ZyXEL Communications P660HWDXV2 802.11g Wireless ADSL Gateway User Manual SMG 700 User s Guide V1 00 Nov 2004

ZyXEL Communications Corporation 802.11g Wireless ADSL Gateway SMG 700 User s Guide V1 00 Nov 2004

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Chapter 6 LAN SetupP-660HW-Dx v2 User’s Guide 101The following table describes the labels in this screen.6.5 LAN Client ListThis table allows you to assign IP addresses on the LAN to specific individual computers based on their MAC Addresses. Every Ethernet device has a unique MAC (Media Access Control) address. The MAC address is assigned at the factory and consists of six pairs of hexadecimal characters, for example, 00:A0:C5:00:00:02.To change your ZyXEL Device’s static DHCP settings, click Network > LAN > Client List. The screen appears as shown.Table 28 DHCP SetupLABEL DESCRIPTIONDHCP SetupDHCP If set to Server, your ZyXEL Device can assign IP addresses, an IP default gateway and DNS servers to Windows 95, Windows NT and other systems that support the DHCP client.If set to None, the DHCP server will be disabled. If set to Relay, the ZyXEL Device acts as a surrogate DHCP server and relays DHCP requests and responses between the remote server and the clients. Enter the IP address of the actual, remote DHCP server in the Remote DHCP Server field in this case. When DHCP is used, the following items need to be set: IP Pool Starting AddressThis field specifies the first of the contiguous addresses in the IP address pool.Pool Size This field specifies the size, or count of the IP address pool.Remote DHCP ServerIf Relay is selected in the DHCP field above then enter the IP address of the actual remote DHCP server here.DNS ServerDNS Servers Assigned by DHCP ServerThe ZyXEL Device passes a DNS (Domain Name System) server IP address to the DHCP clients. Primary DNS ServerSecondary DNS ServerThis field is not available when you set DHCP to Relay.Enter the IP addresses of the DNS servers. The DNS servers are passed to the DHCP clients along with the IP address and the subnet mask.If the fields are left as 0.0.0.0, the ZyXEL Device acts as a DNS proxy and forwards the DHCP client’s DNS query to the real DNS server learned through IPCP and relays the response back to the computer.Apply Click Apply to save your changes to the ZyXEL Device.Cancel Click Cancel to begin configuring this screen afresh.

Chapter 6 LAN SetupP-660HW-Dx v2 User’s Guide102Figure 57 LAN Client ListThe following table describes the labels in this screen.6.6 LAN IP AliasIP alias allows you to partition a physical network into different logical networks over the same Ethernet interface. The ZyXEL Device supports three logical LAN interfaces via its single physical Ethernet interface with the ZyXEL Device itself as the gateway for each LAN network.Table 29 LAN Client ListLABEL DESCRIPTIONIP Address Enter the IP address that you want to assign to the computer on your LAN with the MAC address specified below.The IP address should be within the range of IP addresses you specified in the DHCP Setup for the DHCP client.MAC Address Enter the MAC address of a computer on your LAN.Add Click Add to add a static DHCP entry. # This is the index number of the static IP table entry (row).Status This field displays whether the client is connected to the ZyXEL Device.Host Name This field displays the computer host name.IP Address This field displays the IP address relative to the # field listed above.MAC Address The MAC (Media Access Control) or Ethernet address on a LAN (Local Area Network) is unique to your computer (six pairs of hexadecimal notation).A network interface card such as an Ethernet adapter has a hardwired address that is assigned at the factory. This address follows an industry standard that ensures no other adapter has a similar address.Reserve Select the check box(es) in each entry to have the ZyXEL Device always assign the selected entry(ies)’s IP address(es) to the corresponding MAC address(es) (and host name(s)). You can select up to 32 entries in this table. Modify Click the modify icon to have the IP address field editable and change it.Apply Click Apply to save your changes to the ZyXEL Device.Cancel Click Cancel to begin configuring this screen afresh.Refresh Click Refresh to reload the DHCP table.

Chapter 6 LAN SetupP-660HW-Dx v2 User’s Guide 103When you use IP alias, you can also configure firewall rules to control access between the LAN's logical networks (subnets)."Make sure that the subnets of the logical networks do not overlap.The following figure shows a LAN divided into subnets A, B, and C.Figure 58 Physical Network & Partitioned Logical NetworksTo change your ZyXEL Device’s IP alias settings, click Network > LAN > IP Alias. The screen appears as shown.Figure 59 LAN IP Alias

Chapter 6 LAN SetupP-660HW-Dx v2 User’s Guide104The following table describes the labels in this screen.Table 30 LAN IP AliasLABEL DESCRIPTIONIP Alias 1, 2 Select the check box to configure another LAN network for the ZyXEL Device.IP Address Enter the IP address of your ZyXEL Device in dotted decimal notation. Alternatively, click the right mouse button to copy and/or paste the IP address.IP Subnet Mask Your ZyXEL Device will automatically calculate the subnet mask based on the IP address that you assign. Unless you are implementing subnetting, use the subnet mask computed by the ZyXEL Device.RIP Direction RIP (Routing Information Protocol, RFC 1058 and RFC 1389) allows a router to exchange routing information with other routers. The RIP Direction field controls the sending and receiving of RIP packets. Select the RIP direction from None/Both/In Only/Out Only. When set to Both or Out Only, the ZyXEL Device will broadcast its routing table periodically. When set to Both or In Only, it will incorporate the RIP information that it receives; when set to None, it will not send any RIP packets and will ignore any RIP packets received.RIP Version The RIP Version field controls the format and the broadcasting method of the RIP packets that the ZyXEL Device sends (it recognizes both formats when receiving). RIP-1 is universally supported but RIP-2 carries more information. RIP-1 is probably adequate for most networks, unless you have an unusual network topology. Both RIP-2B and RIP-2M sends the routing data in RIP-2 format; the difference being that RIP-2B uses subnet broadcasting while RIP-2M uses multicasting. Multicasting can reduce the load on non-router machines since they generally do not listen to the RIP multicast address and so will not receive the RIP packets. However, if one router uses multicasting, then all routers on your network must use multicasting, also. By default, RIP direction is set to Both and the Version set to RIP-1.Apply Click Apply to save your changes to the ZyXEL Device.Cancel Click Cancel to begin configuring this screen afresh.

P-660HW-Dx v2 User’s Guide 105CHAPTER 7 Wireless LANThis chapter discusses how to configure the wireless network settings on your ZyXEL Device. See the appendices for more detailed information about wireless networks.7.1 Wireless Network OverviewThe following figure provides an example of a wireless network.Figure 60 Example of a Wireless NetworkThe wireless network is the part in the blue circle. In this wireless network, devices A and B are called wireless clients. The wireless clients use the access point (AP) to interact with other devices (such as the printer) or with the Internet. Your ZyXEL Device is the AP.Every wireless network must follow these basic guidelines.• Every wireless client in the same wireless network must use the same SSID.The SSID is the name of the wireless network. It stands for Service Set IDentity.• If two wireless networks overlap, they should use different channels.Like radio stations or television channels, each wireless network uses a specific channel, or frequency, to send and receive information.

Chapter 7 Wireless LANP-660HW-Dx v2 User’s Guide106• Every wireless client in the same wireless network must use security compatible with the AP.Security stops unauthorized devices from using the wireless network. It can also protect the information that is sent in the wireless network.7.2 Wireless Security OverviewThe following sections introduce different types of wireless security you can set up in the wireless network.7.2.1 SSIDNormally, the AP acts like a beacon and regularly broadcasts the SSID in the area. You can hide the SSID instead, in which case the AP does not broadcast the SSID. In addition, you should change the default SSID to something that is difficult to guess.This type of security is fairly weak, however, because there are ways for unauthorized devices to get the SSID. In addition, unauthorized devices can still see the information that is sent in the wireless network.7.2.2 MAC Address FilterEvery wireless client has a unique identification number, called a MAC address.1 A MAC address is usually written using twelve hexadecimal characters2; for example, 00A0C5000002 or 00:A0:C5:00:00:02. To get the MAC address for each wireless client, see the appropriate User’s Guide or other documentation.You can use the MAC address filter to tell the AP which wireless clients are allowed or not allowed to use the wireless network. If a wireless client is allowed to use the wireless network, it still has to have the correct settings (SSID, channel, and security). If a wireless client is not allowed to use the wireless network, it does not matter if it has the correct settings.This type of security does not protect the information that is sent in the wireless network. Furthermore, there are ways for unauthorized devices to get the MAC address of an authorized wireless client. Then, they can use that MAC address to use the wireless network.7.2.3 User AuthenticationAuthentication is the process of verifying whether a wireless device is allowed to use the wireless network. You can make every user log in to the wireless network before they can use it. This is called user authentication. However, every wireless client in the wireless network has to support IEEE 802.1x to do this.For wireless networks, there are two typical places to store the user names and passwords for each user.• In the AP: this feature is called a local user database or a local database.1. Some wireless devices, such as scanners, can detect wireless networks but cannot use wireless networks. These kinds of wireless devices might not have MAC addresses.2. Hexadecimal characters are 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, and F.

Chapter 7 Wireless LANP-660HW-Dx v2 User’s Guide 107• In a RADIUS server: this is a server used in businesses more than in homes.If your AP does not provide a local user database and if you do not have a RADIUS server, you cannot set up user names and passwords for your users.Unauthorized devices can still see the information that is sent in the wireless network, even if they cannot use the wireless network. Furthermore, there are ways for unauthorized wireless users to get a valid user name and password. Then, they can use that user name and password to use the wireless network.Local user databases also have an additional limitation that is explained in the next section.7.2.4 EncryptionWireless networks can use encryption to protect the information that is sent in the wireless network. Encryption is like a secret code. If you do not know the secret code, you cannot understand the message.The types of encryption you can choose depend on the type of user authentication. (See Section 7.2.3 on page 106 for information about this.)For example, if the wireless network has a RADIUS server, you can choose WPA or WPA2. If users do not log in to the wireless network, you can choose no encryption, Static WEP, WPA-PSK, or WPA2-PSK.Usually, you should set up the strongest encryption that every wireless client in the wireless network supports. For example, suppose the AP does not have a local user database, and you do not have a RADIUS server. Therefore, there is no user authentication. Suppose the wireless network has two wireless clients. Device A only supports WEP, and device B supports WEP and WPA. Therefore, you should set up Static WEP in the wireless network."It is recommended that wireless networks use WPA-PSK, WPA, or stronger encryption. IEEE 802.1x and WEP encryption are better than none at all, but it is still possible for unauthorized devices to figure out the original information pretty quickly.It is not possible to use WPA-PSK, WPA or stronger encryption with a local user database. In this case, it is better to set up stronger encryption with no authentication than to set up weaker encryption with the local user database.Table 31 Types of Encryption for Each Type of AuthenticationNO AUTHENTICATION RADIUS SERVERWeakest No Security WPAStatic WEPWPA-PSKStrongest WPA2-PSK WPA2

Chapter 7 Wireless LANP-660HW-Dx v2 User’s Guide108When you select WPA2 or WPA2-PSK in your ZyXEL Device, you can also select an option (WPA compatible) to support WPA as well. In this case, if some wireless clients support WPA and some support WPA2, you should set up WPA2-PSK or WPA2 (depending on the type of wireless network login) and select the WPA compatible option in the ZyXEL Device.Many types of encryption use a key to protect the information in the wireless network. The longer the key, the stronger the encryption. Every wireless client in the wireless network must have the same key.7.2.5 One-Touch Intelligent Security Technology (OTIST)With ZyXEL’s OTIST, you set up the SSID and WPA-PSK on the ZyXEL Device. Then, the ZyXEL Device transfers them to the devices in the wireless networks. As a result, you do not have to set up the SSID and encryption on every device in the wireless network.The devices in the wireless network have to support OTIST, and they have to be in range of the ZyXEL Device when you activate it. See Section 7.4 on page 117 for more details.7.3 General Wireless LAN Screen "If you are configuring the ZyXEL Device from a computer connected to the wireless LAN and you change the ZyXEL Device’s SSID or WEP settings, you will lose your wireless connection when you press Apply to confirm. You must then change the wireless settings of your computer to match the ZyXEL Device’s new settings.Click Network > Wireless LAN to open the General screen.Figure 61 Wireless LAN: General

Chapter 7 Wireless LANP-660HW-Dx v2 User’s Guide 109The following table describes the general wireless LAN labels in this screen.See the rest of this chapter for information on the other labels in this screen. 7.3.1 No SecuritySelect No Security to allow wireless clients to communicate with the access points without any data encryption. "If you do not enable any wireless security on your ZyXEL Device, your network is accessible to any wireless networking device that is within range.Table 32 Wireless LAN: GeneralLABEL DESCRIPTIONWireless SetupActive Wireless LANClick the check box to activate wireless LAN.Network Name (SSID)(Service Set IDentity) The SSID identifies the Service Set with which a wireless client is associated. Wireless clients associating to the access point (AP) must have the same SSID. Enter a descriptive name (up to 32 printable 7-bit ASCII characters) for the wireless LAN. Note: If you are configuring the ZyXEL Device from a computer connected to the wireless LAN and you change the ZyXEL Device’s SSID or WEP settings, you will lose your wireless connection when you press Apply to confirm. You must then change the wireless settings of your computer to match the ZyXEL Device’s new settings.Hide SSID Select this check box to hide the SSID in the outgoing beacon frame so a station cannot obtain the SSID through scanning using a site survey tool.Channel SelectionSet the operating frequency/channel depending on your particular region. Select a channel from the drop-down list box. Apply Click Apply to save your changes to the ZyXEL Device.Cancel Click Cancel to reload the previous configuration for this screen.Advanced SetupClick Advanced Setup to display the Wireless Advanced Setup screen and edit more details of your WLAN setup.

Chapter 7 Wireless LANP-660HW-Dx v2 User’s Guide110Figure 62 Wireless: No SecurityThe following table describes the labels in this screen.7.3.2 WEP EncryptionWEP encryption scrambles the data transmitted between the wireless clients and the access points to keep network communications private. It encrypts unicast and multicast communications in a network. Both the wireless clients and the access points must use the same WEP key.Your ZyXEL Device allows you to configure up to four 64-bit, 128-bit or 256-bit WEP keys but only one key can be enabled at any one time.In order to configure and enable WEP encryption; click Network > Wireless LAN to display the General screen. Select Static WEP from the Security Mode list.Table 33 Wireless No SecurityLABEL DESCRIPTIONSecurity Mode Choose No Security from the drop-down list box.Apply Click Apply to save your changes to the ZyXEL Device.Cancel Click Cancel to reload the previous configuration for this screen.Advanced SetupClick Advanced Setup to display the Wireless Advanced Setup screen and edit more details of your WLAN setup.

Chapter 7 Wireless LANP-660HW-Dx v2 User’s Guide 111Figure 63 Wireless: Static WEP EncryptionThe following table describes the wireless LAN security labels in this screen.7.3.3 WPA-PSK/WPA2-PSK In order to configure and enable WPA(2)-PSK authentication; click Network > Wireless LAN to display the General screen. Select WPA-PSK or WPA2-PSK from the Security Mode list.Table 34 Wireless: Static WEP EncryptionLABEL DESCRIPTIONSecurity Mode Choose Static WEP from the drop-down list box.Passphrase Enter a Passphrase (up to 32 printable characters) and clicking Generate. The ZyXEL Device automatically generates a WEP key.WEP Key The WEP keys are used to encrypt data. Both the ZyXEL Device and the wireless clients must use the same WEP key for data transmission.If you want to manually set the WEP key, enter any 5, 13 or 29 characters (ASCII string) or 10, 26 or 58 hexadecimal characters ("0-9", "A-F") for a 64-bit, 128-bit or 256-bit WEP key respectively.Apply Click Apply to save your changes to the ZyXEL Device.Cancel Click Cancel to reload the previous configuration for this screen.Advanced SetupClick Advanced Setup to display the Wireless Advanced Setup screen and edit more details of your WLAN setup.

Chapter 7 Wireless LANP-660HW-Dx v2 User’s Guide112Figure 64 Wireless: WPA-PSK/WPA2-PSKThe following table describes the wireless LAN security labels in this screen.Table 35 Wireless: WPA-PSK/WPA2-PSKLABEL DESCRIPTIONSecurity Mode Choose WPA-PSK or WPA2-PSK from the drop-down list box.WPA Compatible This check box is available only when you select WPA2-PSK or WPA2 in the Security Mode field.Select the check box to have both WPA2 and WPA wireless clients be able to communicate with the ZyXEL Device even when the ZyXEL Device is using WPA2-PSK or WPA2.Pre-Shared Key The encryption mechanisms used for WPA/WPA2 and WPA-PSK/WPA2-PSK are the same. The only difference between the two is that WPA-PSK/WPA2-PSK uses a simple common password, instead of user-specific credentials.Type a pre-shared key from 8 to 63 case-sensitive ASCII characters (including spaces and symbols).ReAuthentication Timer (In Seconds)Specify how often wireless clients have to resend usernames and passwords in order to stay connected. Enter a time interval between 10 and 9999 seconds. The default time interval is 1800 seconds (30 minutes). Note: If wireless client authentication is done using a RADIUS server, the reauthentication timer on the RADIUS server has priority.

Chapter 7 Wireless LANP-660HW-Dx v2 User’s Guide 1137.3.4 WPA/WPA2In order to configure and enable WPA/WPA2; click the Wireless LAN link under Network to display the General screen. Select WPA or WPA2 from the Security Mode list.Idle Timeout (In Seconds)The ZyXEL Device automatically disconnects a wireless station from the wireless network after a period of inactivity. The wireless station needs to send the username and password again before it can use the wireless network again. Some wireless clients may prompt users for a username and password; other clients may use saved login credentials. In either case, there is usually a short delay while the wireless client logs in to the wireless network again.This value is usually smaller when the wireless network is keeping track of how much time each wireless station is connected to the wireless network (for example, using an authentication server). If the wireless network is not keeping track of this information, you can usually set this value higher to reduce the number of delays caused by logging in again.Group Key Update Timer (In Seconds)The Group Key Update Timer is the rate at which the AP (if using WPA-PSK/WPA2-PSK key management) or RADIUS server (if using WPA(2) key management) sends a new group key out to all clients. The re-keying process is the WPA(2) equivalent of automatically changing the WEP key for an AP and all stations in a WLAN on a periodic basis. Setting of the Group Key Update Timer is also supported in WPA-PSK/WPA2-PSK mode. The default is 1800 seconds (30 minutes).Apply Click Apply to save your changes to the ZyXEL Device.Cancel Click Cancel to reload the previous configuration for this screen.Advanced Setup Click Advanced Setup to display the Wireless Advanced Setup screen and edit more details of your WLAN setup.Table 35 Wireless: WPA-PSK/WPA2-PSKLABEL DESCRIPTION

Chapter 7 Wireless LANP-660HW-Dx v2 User’s Guide114Figure 65 Wireless: WPA/WPA2The following table describes the wireless LAN security labels in this screen.Table 36 Wireless: WPA/WPA2LABEL DESCRIPTIONWPA Compatible This check box is available only when you select WPA2-PSK or WPA2 in the Security Mode field.Select the check box to have both WPA2 and WPA wireless clients be able to communicate with the ZyXEL Device even when the ZyXEL Device is using WPA2-PSK or WPA2.ReAuthentication Timer (In Seconds)Specify how often wireless clients have to resend usernames and passwords in order to stay connected. Enter a time interval between 10 and 9999 seconds. The default time interval is 1800 seconds (30 minutes). Note: If wireless client authentication is done using a RADIUS server, the reauthentication timer on the RADIUS server has priority.Idle Timeout (In Seconds)The ZyXEL Device automatically disconnects a wireless client from the wired network after a period of inactivity. The wireless client needs to enter the username and password again before access to the wired network is allowed. The default time interval is 3600 seconds (or 1 hour).

Chapter 7 Wireless LANP-660HW-Dx v2 User’s Guide 1157.3.5 Wireless LAN Advanced SetupTo configure advanced wireless settings, click the Advanced Setup button in the General screen. The screen appears as shown.Group Key Update Timer (In Seconds)The Group Key Update Timer is the rate at which the AP (if using WPA-PSK/WPA2-PSK key management) or RADIUS server (if using WPA(2) key management) sends a new group key out to all clients. The re-keying process is the WPA(2) equivalent of automatically changing the WEP key for an AP and all stations in a WLAN on a periodic basis. Setting of the Group Key Update Timer is also supported in WPA-PSK/WPA2-PSK mode. The default is 1800 seconds (30 minutes).Authentication ServerIP Address Enter the IP address of the external authentication server in dotted decimal notation.Port Number Enter the port number of the external authentication server. The default port number is 1812. You need not change this value unless your network administrator instructs you to do so with additional information. Shared Secret Enter a password (up to 31 alphanumeric characters) as the key to be shared between the external authentication server and the ZyXEL Device.The key must be the same on the external authentication server and your ZyXEL Device. The key is not sent over the network. Accounting Server (optional)IP Address Enter the IP address of the external accounting server in dotted decimal notation.Port Number Enter the port number of the external accounting server. The default port number is 1813. You need not change this value unless your network administrator instructs you to do so with additional information. Shared Secret Enter a password (up to 31 alphanumeric characters) as the key to be shared between the external accounting server and the ZyXEL Device.The key must be the same on the external accounting server and your ZyXEL Device. The key is not sent over the network. Apply Click Apply to save your changes to the ZyXEL Device.Cancel Click Cancel to reload the previous configuration for this screen.Advanced Setup Click Advanced Setup to display the Wireless Advanced Setup screen and edit more details of your WLAN setup.Table 36 Wireless: WPA/WPA2 (continued)LABEL DESCRIPTION

Chapter 7 Wireless LANP-660HW-Dx v2 User’s Guide116Figure 66 AdvancedThe following table describes the labels in this screen. Table 37 Wireless LAN: AdvancedLABEL DESCRIPTIONWireless Advanced SetupRTS/CTS ThresholdEnter a value between 0 and 2432.Fragmentation ThresholdThis is the maximum data fragment size that can be sent. Enter a value between 256 and 2432.Output Power Set the output power of the ZyXEL Device in this field. This control changes the strength of the ZyXEL Device's antenna gain or transmission power. Antenna gain is the increase in coverage. Higher antenna gain improves the range of the signal for better communications. If there is a high density of APs within an area, decrease the output power of the ZyXEL Device to reduce interference with other APs.The options are Maximum, Middle and Minimum.Preamble Select Long preamble if you are unsure what preamble mode the wireless adapters support, and to provide more reliable communications in busy wireless networks. Select Short preamble if you are sure the wireless adapters support it, and to provide more efficient communications.Select Dynamic to have the ZyXEL Device automatically use short preamble when wireless adapters support it, otherwise the ZyXEL Device uses long preamble.802.11 Mode Select 802.11b Only to allow only IEEE 802.11b compliant WLAN devices to associate with the ZyXEL Device.Select 802.11g Only to allow only IEEE 802.11g compliant WLAN devices to associate with the ZyXEL Device.Select Mixed to allow either IEEE802.11b or IEEE802.11g compliant WLAN devices to associate with the ZyXEL Device. The transmission rate of your ZyXEL Device might be reduced.Max. Frame BurstEnable Maximum Frame Burst to help eliminate collisions in mixed-mode networks (networks with both IEEE 802.11g and IEEE 802.11b traffic) and enhance the performance of both pure IEEE 802.11g and mixed IEEE 802.11b/g networks. Maximum Frame Burst sets the maximum time, in micro-seconds, that the ZZyXEL Device transmits IEEE 802.11g wireless traffic only. Type the maximum frame burst between 0 and 1800 (650, 1000 or 1800 recommended). Enter 0 to disable this feature.Back Click Back to return to the previous screen.

Chapter 7 Wireless LANP-660HW-Dx v2 User’s Guide 1177.4 OTIST In a wireless network, the wireless clients must have the same SSID and security settings as the access point (AP) or wireless router (we will refer to both as “AP” here) in order to associate with it. Traditionally this meant that you had to configure the settings on the AP and then manually configure the exact same settings on each wireless client.OTIST (One-Touch Intelligent Security Technology) allows you to transfer your AP’s SSID and WPA-PSK security settings to wireless clients that support OTIST and are within transmission range. You can also choose to have OTIST generate a WPA-PSK key for you if you didn’t configure one manually."OTIST replaces the pre-configured wireless settings on the wireless clients.7.4.1 Enabling OTISTYou must enable OTIST on both the AP and wireless client before you start transferring settings."The AP and wireless client(s) MUST use the same Setup key.7.4.1.1 APYou can enable OTIST using the RESET button or the web configurator. 7.4.1.1.1 Reset buttonIf you use the RESET button, the default (01234567) or previous saved (through the web configurator) Setup key is used to encrypt the settings that you want to transfer. Hold in the RESET button for three to eight seconds. "If you hold in the RESET button too long, the device will reset to the factory defaults!Apply Click Apply to save your changes to the ZyXEL Device.Cancel Click Cancel to reload the previous configuration for this screen.Table 37 Wireless LAN: Advanced (continued)LABEL DESCRIPTION

Chapter 7 Wireless LANP-660HW-Dx v2 User’s Guide1187.4.1.1.2 Web ConfiguratorClick the Network > Wireless LAN > OTIST. The following screen displays.Figure 67 OTISTThe following table describes the labels in this screen.7.4.1.2 Wireless ClientStart the ZyXEL utility and click the Adapter tab. Select the OTIST check box, enter the same Setup Key as your AP’s and click Save.Table 38 OTISTLABEL DESCRIPTIONSetup Key Type an OTIST Setup Key of exactly eight ASCII characters in length. The default OTIST setup key is "01234567".Note: If you change the OTIST setup key here, you must also make the same change on the wireless client(s).Yes! If you want OTIST to automatically generate a WPA-PSK, you must:• Change your security to any security other than WPA-PSK in the Wireless LAN > General screen.• Select the Yes! checkbox in the OTIST screen and click Start.• The wireless screen displays an auto generated WPA-PSK and is now in WPA-PSK security mode. The WPA-PSK security settings are assigned to the wireless client when you start OTIST.Note: If you already have a WPA-PSK configured in the Wireless LAN > General screen, and you run OTIST with Yes! selected, OTIST will use the existing WPA-PSK.Start Click Start to encrypt the wireless security data using the setup key and have the ZyXEL Device set the wireless client(s) to use the same wireless settings as the ZyXEL Device. You must also activate and start OTIST on the wireless client(s) all within three minutes.

Chapter 7 Wireless LANP-660HW-Dx v2 User’s Guide 119Figure 68 Example Wireless Client OTIST Screen7.4.2 Starting OTIST"You must click Start in the AP OTIST web configurator screen and in the wireless client(s) Adapter screen all within three minutes (at the time of writing). You can start OTIST in the wireless clients and AP in any order but they must all be within range and have OTIST enabled.1In the AP, a web configurator screen pops up showing you the security settings to transfer. You can use the key in this screen to set up WPA-PSK encryption manually for non-OTIST devices in the wireless network. After reviewing the settings, click OK.Figure 69 Security Key2This screen appears while OTIST settings are being transferred. It closes when the transfer is complete. Figure 70 OTIST in Progress (AP)

Chapter 7 Wireless LANP-660HW-Dx v2 User’s Guide120Figure 71 OTIST in progress (Client)In the wireless client, you see this screen if it can’t find an OTIST-enabled AP (with the same Setup key). Click OK to go back to the ZyXEL utility main screen.Figure 72 No AP with OTIST Found• If there is more than one OTIST-enabled AP within range, you see a screen asking you to select one AP to get settings from.7.4.3 Notes on OTIST1If you enabled OTIST in the wireless client, you see this screen each time you start the utility. Click Ye s for it to search for an OTIST-enabled AP.Figure 73 Start OTIST?2If an OTIST-enabled wireless client loses its wireless connection for more than ten seconds, it will search for an OTIST-enabled AP for up to one minute. (If you manually have the wireless client search for an OTIST-enabled AP, there is no timeout; click Cancel in the OTIST progress screen to stop the search.)3When the wireless client finds an OTIST-enabled AP, you must still click Start in the AP OTIST web configurator screen or hold in the RESET button (for one to five seconds) for the AP to transfer settings.4If you change the SSID or the keys on the AP after using OTIST, you need to run OTIST again or enter them manually in the wireless client(s).5If you configure OTIST to generate a WPA-PSK key, this key changes each time you run OTIST. Therefore, if a new wireless client joins your wireless network, you need to run OTIST on the AP and ALL wireless clients again.

Chapter 7 Wireless LANP-660HW-Dx v2 User’s Guide 1217.5 MAC Filter The MAC filter screen allows you to configure the ZyXEL Device to give exclusive access to up to 32 devices (Allow) or exclude up to 32 devices from accessing the ZyXEL Device (Deny). Every Ethernet device has a unique MAC (Media Access Control) address. The MAC address is assigned at the factory and consists of six pairs of hexadecimal characters, for example, 00:A0:C5:00:00:02. You need to know the MAC address of the devices to configure this screen.To change your ZyXEL Device’s MAC filter settings, click Network > Wireless LAN > MAC Filter. The screen appears as shown.Figure 74 MAC Address FilterThe following table describes the labels in this menu.Table 39 MAC Address FilterLABEL DESCRIPTIONActive MAC FilterSelect the check box to enable MAC address filtering.Filter Action Define the filter action for the list of MAC addresses in the MAC Address table. Select Deny to block access to the ZyXEL Device, MAC addresses not listed will be allowed to access the ZyXEL Device Select Allow to permit access to the ZyXEL Device, MAC addresses not listed will be denied access to the ZyXEL Device. Set This is the index number of the MAC address.

Chapter 7 Wireless LANP-660HW-Dx v2 User’s Guide1227.6 WMM QoSWMM (Wi-Fi MultiMedia) QoS (Quality of Service) allows you to prioritize wireless traffic according to the delivery requirements of individual services.WMM is a part of the IEEE 802.11e QoS enhancement to certified Wi-Fi wireless networks.7.6.1 WMM QoS ExampleWhen WMM QoS is not enabled, all traffic streams are given the same access throughput to the wireless network. If the introduction of another traffic stream creates a data transmission demand that exceeds the current network capacity, then the new traffic stream reduces the throughput of the other traffic streams.When WMM QoS is enabled, the streams are prioritized according to the needs of the application. You can assign different priorities to different applications. This prevents reductions in data transmission for applications that are sensitive.7.6.2 WMM QoS PrioritiesThe following table describes the priorities that you can apply to traffic that the ZyXEL Device sends to the wireless network.MAC AddressEnter the MAC addresses of the wireless client that are allowed or denied access to the ZyXEL Device in these address fields. Enter the MAC addresses in a valid MAC address format, that is, six hexadecimal character pairs, for example, 12:34:56:78:9a:bc.Apply Click Apply to save your changes to the ZyXEL Device.Cancel Click Cancel to reload the previous configuration for this screen.Table 39 MAC Address FilterLABEL DESCRIPTIONTable 40 WMM QoS PrioritiesPRIORITY LEVELS:Highest Typically used for voice traffic or video that is especially sensitive to jitter (variations in delay). Use the highest priority to reduce latency for improved voice quality.High Typically used for video traffic which has some tolerance for jitter but needs to be prioritized over other data traffic.Mid Typically used for traffic from applications or devices that lack QoS capabilities. Use mid priority for traffic that is less sensitive to latency, but is affected by long delays, such as Internet surfing.Low This is typically used for non-critical “background” traffic such as bulk transfers and print jobs that are allowed but that should not affect other applications and users. Use low priority for applications that do not have strict latency and throughput requirements.

Chapter 7 Wireless LANP-660HW-Dx v2 User’s Guide 1237.6.3 ServicesThe commonly used services and port numbers are shown in the following table. Please refer to RFC 1700 for further information about port numbers. Next to the name of the service, two fields appear in brackets. The first field indicates the IP protocol type (TCP, UDP, or ICMP). The second field indicates the IP port number that defines the service. (Note that there may be more than one IP protocol type. For example, look at the DNS service. (UDP/TCP:53) means UDP port 53 and TCP port 53. Table 41 Commonly Used ServicesSERVICE DESCRIPTIONAIM/New-ICQ(TCP:5190) AOL’s Internet Messenger service, used as a listening port by ICQ.AUTH(TCP:113) Authentication protocol used by some servers.BGP(TCP:179) Border Gateway Protocol.BOOTP_CLIENT(UDP:68) DHCP Client.BOOTP_SERVER(UDP:67) DHCP Server.CU-SEEME(TCP/UDP:7648, 24032) A popular videoconferencing solution from White Pines Software.DNS(UDP/TCP:53) Domain Name Server, a service that matches web names (e.g. www.zyxel.com) to IP numbers.FINGER(TCP:79) Finger is a UNIX or Internet related command that can be used to find out if a user is logged on.FTP(TCP:20.21) File Transfer Program, a program to enable fast transfer of files, including large files that may not be possible by e-mail.H.323(TCP:1720) NetMeeting uses this protocol.HTTP(TCP:80) Hyper Text Transfer Protocol - a client/server protocol for the world wide web.HTTPS(TCP:443) HTTPS is a secured http session often used in e-commerce.ICQ(UDP:4000) This is a popular Internet chat program.IKE(UDP:500) The Internet Key Exchange algorithm is used for key distribution and management.IPSEC_TUNNEL(AH:0) The IPSEC AH (Authentication Header) tunneling protocol uses this service.IPSEC_TUNNEL(ESP:0) The IPSEC ESP (Encapsulation Security Protocol) tunneling protocol uses this service.IRC(TCP/UDP:6667) This is another popular Internet chat program.MSN Messenger(TCP:1863) Microsoft Networks’ messenger service uses this protocol. MULTICAST(IGMP:0) Internet Group Multicast Protocol is used when sending packets to a specific group of hosts.NEW-ICQ(TCP:5190) An Internet chat program.NEWS(TCP:144) A protocol for news groups.NFS(UDP:2049) Network File System - NFS is a client/server distributed file service that provides transparent file sharing for network environments.NNTP(TCP:119) Network News Transport Protocol is the delivery mechanism for the USENET newsgroup service.

Chapter 7 Wireless LANP-660HW-Dx v2 User’s Guide1247.7 QoS ScreenThe QoS screen by default allows you to automatically give a service a priority level according to the ToS value in the IP header of the packets it sends.PING(ICMP:0) Packet INternet Groper is a protocol that sends out ICMP echo requests to test whether or not a remote host is reachable.POP3(TCP:110) Post Office Protocol version 3 lets a client computer get e-mail from a POP3 server through a temporary connection (TCP/IP or other).PPTP(TCP:1723) Point-to-Point Tunneling Protocol enables secure transfer of data over public networks. This is the control channel.PPTP_TUNNEL(GRE:0) Point-to-Point Tunneling Protocol enables secure transfer of data over public networks. This is the data channel.RCMD(TCP:512) Remote Command Service.REAL_AUDIO(TCP:7070) A streaming audio service that enables real time sound over the web.REXEC(TCP:514) Remote Execution Daemon.RLOGIN(TCP:513) Remote Login.RTELNET(TCP:107) Remote Telnet.RTSP(TCP/UDP:554) The Real Time Streaming (media control) Protocol (RTSP) is a remote control for multimedia on the Internet. SFTP(TCP:115) Simple File Transfer Protocol.SMTP(TCP:25) Simple Mail Transfer Protocol is the message-exchange standard for the Internet. SMTP enables you to move messages from one e-mail server to another.SNMP(TCP/UDP:161) Simple Network Management Program.SNMP-TRAPS(TCP/UDP:162) Traps for use with the SNMP (RFC:1215).SQL-NET(TCP:1521) Structured Query Language is an interface to access data on many different types of database systems, including mainframes, midrange systems, UNIX systems and network servers.SSH(TCP/UDP:22) Secure Shell Remote Login Program.STRM WORKS(UDP:1558) Stream Works Protocol.SYSLOG(UDP:514) Syslog allows you to send system logs to a UNIX server.TACACS(UDP:49) Login Host Protocol used for (Terminal Access Controller Access Control System).TELNET(TCP:23) Telnet is the login and terminal emulation protocol common on the Internet and in UNIX environments. It operates over TCP/IP networks. Its primary function is to allow users to log into remote host systems.TFTP(UDP:69) Trivial File Transfer Protocol is an Internet file transfer protocol similar to FTP, but uses the UDP (User Datagram Protocol) rather than TCP (Transmission Control Protocol).VDOLIVE(TCP:7000) Another videoconferencing solution.Table 41 Commonly Used Services (continued)SERVICE DESCRIPTION

Chapter 7 Wireless LANP-660HW-Dx v2 User’s Guide 1257.7.1 ToS (Type of Service) and WMM QoSToS defines the DS (Differentiated Service) field in the IP packet header. The ToS value of outgoing packets is between 0 and 255. 0 is the lowest priority.WMM QoS checks the ToS in the header of transmitted data packets. It gives the application a priority according to this number. If the ToS is not specified, then transmitted data is treated as normal or best-effort traffic.Click Network > Wireless LAN > QoS. The following screen displays.Figure 75 Wireless LAN: QoSThe following table describes the fields in this screen.Table 42 Wireless Lan: QoSLABEL DESCRIPTIONQoSEnable WMM QoS Select the check box to enable WMM QoS on the ZyXEL Device.WMM QoS Policy Select Default to have the ZyXEL Device automatically give a service a priority level according to the ToS value in the IP header of packets it sends.Select Application Priority from the drop-down list box to display a table of application names, services, ports and priorities to which you want to apply WMM QoS.# This is the number of an individual application entry.Name This field displays a description given to an application entry.Service This field displays either FTP, WWW, E-mail or a User Defined service to which you want to apply WMM QoS.

Chapter 7 Wireless LANP-660HW-Dx v2 User’s Guide1267.7.2 Application Priority ConfigurationTo edit a WMM QoS application entry, click the edit icon ( ) under Modify. The following screen displays.Figure 76 Application Priority ConfigurationThe following table describes the fields in this screen.Dest Port This field displays the destination port number to which the application sends traffic.Priority This field displays the WMM QoS priority for traffic bandwidth.Modify Click the to open the Application Priority Configuration screen. Modify an existing application entry or create a application entry in the Application Priority Configuration screen.Click the Remove icon to delete an application entry.Apply Click Apply to save your changes back to the ZyXEL Device.Cancel Click Cancel to reload the previous configuration for this screen.Table 42 Wireless Lan: QoS (continued)LABEL DESCRIPTIONTable 43 Application Priority ConfigurationLABEL DESCRIPTIONApplication Priority ConfigurationName Type a description of the application priority.

Chapter 7 Wireless LANP-660HW-Dx v2 User’s Guide 127Service The following is a description of the applications you can prioritize with WMM QoS. Select a service from the drop-down list box. • FTPFile Transfer Program enables fast transfer of files, including large files that may not be possible by e-mail. FTP uses port number 21.• E-MailElectronic mail consists of messages sent through a computer network to specific groups or individuals. Here are some default ports for e-mail: POP3 - port 110IMAP - port 143SMTP - port 25HTTP - port 80•WWWThe World Wide Web is an Internet system to distribute graphical, hyper-linked information, based on Hyper Text Transfer Protocol (HTTP) - a client/server protocol for the World Wide Web. The Web is not synonymous with the Internet; rather, it is just one service on the Internet. Other services on the Internet include Internet Relay Chat and Newsgroups. The Web is accessed through use of a browser.• User-DefinedUser-defined services are user specific services configured using known ports and applications.Dest Port This displays the port the selected service uses. Type a port number in the field provided if you want to use a different port to the default port. See table Table 41 on page 123 for information on port numbers.Priority Select a priority from the drop-down list box. Apply Click Apply to save your changes back to the ZyXEL Device.Cancel Click Cancel to return to the previous screen without saving your changes.Table 43 Application Priority Configuration (continued)LABEL DESCRIPTION

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P-660HW-Dx v2 User’s Guide 129CHAPTER 8 Network Address Translation(NAT) ScreensThis chapter discusses how to configure NAT on the ZyXEL Device.8.1 NAT Overview NAT (Network Address Translation - NAT, RFC 1631) is the translation of the IP address of a host in a packet, for example, the source address of an outgoing packet, used within one network to a different IP address known within another network. 8.1.1 NAT DefinitionsInside/outside denotes where a host is located relative to the ZyXEL Device, for example, the computers of your subscribers are the inside hosts, while the web servers on the Internet are the outside hosts. Global/local denotes the IP address of a host in a packet as the packet traverses a router, for example, the local address refers to the IP address of a host when the packet is in the local network, while the global address refers to the IP address of the host when the same packet is traveling in the WAN side. Note that inside/outside refers to the location of a host, while global/local refers to the IP address of a host used in a packet. Thus, an inside local address (ILA) is the IP address of an inside host in a packet when the packet is still in the local network, while an inside global address (IGA) is the IP address of the same inside host when the packet is on the WAN side. The following table summarizes this information.NAT never changes the IP address (either local or global) of an outside host.Table 44 NAT DefinitionsITEM DESCRIPTIONInside This refers to the host on the LAN.Outside This refers to the host on the WAN.Local This refers to the packet address (source or destination) as the packet travels on the LAN.Global This refers to the packet address (source or destination) as the packet travels on the WAN.

Chapter 8 Network Address Translation (NAT) ScreensP-660HW-Dx v2 User’s Guide1308.1.2 What NAT DoesIn the simplest form, NAT changes the source IP address in a packet received from a subscriber (the inside local address) to another (the inside global address) before forwarding the packet to the WAN side. When the response comes back, NAT translates the destination address (the inside global address) back to the inside local address before forwarding it to the original inside host. Note that the IP address (either local or global) of an outside host is never changed.The global IP addresses for the inside hosts can be either static or dynamically assigned by the ISP. In addition, you can designate servers, for example, a web server and a telnet server, on your local network and make them accessible to the outside world. If you do not define any servers (for Many-to-One and Many-to-Many Overload mapping – see Table 45 on page 132), NAT offers the additional benefit of firewall protection. With no servers defined, your ZyXEL Device filters out all incoming inquiries, thus preventing intruders from probing your network. For more information on IP address translation, refer to RFC 1631, The IP Network Address Translator (NAT).8.1.3 How NAT WorksEach packet has two addresses – a source address and a destination address. For outgoing packets, the ILA (Inside Local Address) is the source address on the LAN, and the IGA (Inside Global Address) is the source address on the WAN. For incoming packets, the ILA is the destination address on the LAN, and the IGA is the destination address on the WAN. NAT maps private (local) IP addresses to globally unique ones required for communication with hosts on other networks. It replaces the original IP source address (and TCP or UDP source port numbers for Many-to-One and Many-to-Many Overload NAT mapping) in each packet and then forwards it to the Internet. The ZyXEL Device keeps track of the original addresses and port numbers so incoming reply packets can have their original values restored. The following figure illustrates this.Figure 77 How NAT Works8.1.4 NAT ApplicationThe following figure illustrates a possible NAT application, where three inside LANs (logical LANs using IP Alias) behind the ZyXEL Device can communicate with three distinct WAN networks. More examples follow at the end of this chapter.

Chapter 8 Network Address Translation (NAT) ScreensP-660HW-Dx v2 User’s Guide 131Figure 78 NAT Application With IP Alias8.1.5 NAT Mapping TypesNAT supports five types of IP/port mapping. They are:•One to One: In One-to-One mode, the ZyXEL Device maps one local IP address to one global IP address.•Many to One: In Many-to-One mode, the ZyXEL Device maps multiple local IP addresses to one global IP address. This is equivalent to SUA (for instance, PAT, port address translation), ZyXEL’s Single User Account feature that previous ZyXEL routers supported (the SUA Only option in today’s routers). •Many to Many Overload: In Many-to-Many Overload mode, the ZyXEL Device maps the multiple local IP addresses to shared global IP addresses.•Many-to-Many No Overload: In Many-to-Many No Overload mode, the ZyXEL Device maps each local IP address to a unique global IP address. •Server: This type allows you to specify inside servers of different services behind the NAT to be accessible to the outside world.Port numbers do NOT change for One-to-One and Many-to-Many No Overload NAT mapping types.

Chapter 8 Network Address Translation (NAT) ScreensP-660HW-Dx v2 User’s Guide132The following table summarizes these types.8.2 SUA (Single User Account) Versus NATSUA (Single User Account) is a ZyNOS implementation of a subset of NAT that supports two types of mapping, Many-to-One and Server. The ZyXEL Device also supports Full Feature NAT to map multiple global IP addresses to multiple private LAN IP addresses of clients or servers using mapping types as outlined in Table 45 on page 132. • Choose SUA Only if you have just one public WAN IP address for your ZyXEL Device.• Choose Full Feature if you have multiple public WAN IP addresses for your ZyXEL Device.8.3 SIP ALGSome applications, such as SIP, cannot operate through NAT (are NAT un-friendly) because they embed IP addresses and port numbers in their packets’ data payload. Some NAT routers may include a SIP Application Layer Gateway (ALG). An Application Layer Gateway (ALG) manages a specific protocol (such as SIP, H.323 or FTP) at the application layer. A SIP ALG allows SIP calls to pass through NAT by examining and translating IP addresses embedded in the data stream. When the ZyXEL Device registers with the SIP register server, the SIP ALG translates the ZyXEL Device’s private IP address inside the SIP data stream to a public IP address. You do not need to use STUN or an outbound proxy if your ZyXEL Device is behind a SIP ALG. Table 45 NAT Mapping TypesTYPE IP MAPPINGOne-to-One ILA1ÅÆ IGA1Many-to-One (SUA/PAT) ILA1ÅÆ IGA1ILA2ÅÆ IGA1…Many-to-Many Overload ILA1ÅÆ IGA1ILA2ÅÆ IGA2ILA3ÅÆ IGA1ILA4ÅÆ IGA2…Many-to-Many No Overload ILA1ÅÆ IGA1ILA2ÅÆ IGA2ILA3ÅÆ IGA3…Server Server 1 IPÅÆ IGA1Server 2 IPÅÆ IGA1Server 3 IPÅÆ IGA1

Chapter 8 Network Address Translation (NAT) ScreensP-660HW-Dx v2 User’s Guide 1338.4 NAT General Setup You must create a firewall rule in addition to setting up SUA/NAT, to allow traffic from the WAN to be forwarded through the ZyXEL Device. Click Network > NAT to open the following screen. Figure 79 NAT General The following table describes the labels in this screen. Table 46 NAT GeneralLABEL DESCRIPTIONActive Network Address Translation (NAT)Select this check box to enable NAT.SUA Only Select this radio button if you have just one public WAN IP address for your ZyXEL Device. Full Feature Select this radio button if you have multiple public WAN IP addresses for your ZyXEL Device. Max NAT/Firewall Session Per UserWhen computers use peer to peer applications, such as file sharing applications, they need to establish NAT sessions. If you do not limit the number of NAT sessions a single client can establish, this can result in all of the available NAT sessions being used. In this case, no additional NAT sessions can be established, and users may not be able to access the Internet. Each NAT session establishes a corresponding firewall session. Use this field to limit the number of NAT/firewall sessions each client computer can establish through the ZyXEL Device. If your network has a small number of clients using peer to peer applications, you can raise this number to ensure that their performance is not degraded by the number of NAT sessions they can establish. If your network has a large number of users using peer to peer applications, you can lower this number to ensure no single client is using all of the available NAT sessions. Enable SIP ALGSelect this option if you want to enable SIP ALG, for example, to use an IP phone through your NAT enabled ZyXEL Device.Apply Click Apply to save your changes to the ZyXEL Device.Cancel Click Cancel to reload the previous configuration for this screen.

Chapter 8 Network Address Translation (NAT) ScreensP-660HW-Dx v2 User’s Guide1348.5 Port Forwarding A port forwarding set is a list of inside (behind NAT on the LAN) servers, for example, web or FTP, that you can make visible to the outside world even though NAT makes your whole inside network appear as a single computer to the outside world. You may enter a single port number or a range of port numbers to be forwarded, and the local IP address of the desired server. The port number identifies a service; for example, web service is on port 80 and FTP on port 21. In some cases, such as for unknown services or where one server can support more than one service (for example both FTP and web service), it might be better to specify a range of port numbers. You can allocate a server IP address that corresponds to a port or a range of ports.Many residential broadband ISP accounts do not allow you to run any server processes (such as a Web or FTP server) from your location. Your ISP may periodically check for servers and may suspend your account if it discovers any active services at your location. If you are unsure, refer to your ISP.8.5.1 Default Server IP AddressIn addition to the servers for specified services, NAT supports a default server IP address. A default server receives packets from ports that are not specified in this screen."If you do not assign a Default Server IP address, the ZyXEL Device discards all packets received for ports that are not specified here or in the remote management setup.8.5.2 Port Forwarding: Services and Port NumbersUse the Port Forwarding screen to forward incoming service requests to the server(s) on your local network. The most often used port numbers are shown in the following table. Please refer to RFC 1700 for further information about port numbers. Table 47 Services and Port NumbersSERVICES PORT NUMBERECHO 7FTP (File Transfer Protocol) 21SMTP (Simple Mail Transfer Protocol) 25DNS (Domain Name System) 53Finger 79HTTP (Hyper Text Transfer protocol or WWW, Web) 80POP3 (Post Office Protocol) 110NNTP (Network News Transport Protocol) 119SNMP (Simple Network Management Protocol) 161

Chapter 8 Network Address Translation (NAT) ScreensP-660HW-Dx v2 User’s Guide 1358.5.3 Configuring Servers Behind Port Forwarding (Example)Let's say you want to assign ports 21-25 to one FTP, Telnet and SMTP server (A in the example), port 80 to another (B in the example) and assign a default server IP address of 192.168.1.35 to a third (C in the example). You assign the LAN IP addresses and the ISP assigns the WAN IP address. The NAT network appears as a single host on the Internet.Figure 80 Multiple Servers Behind NAT Example8.6 Configuring Port Forwarding "The Port Forwarding screen is available only when you select SUA Only in the NAT > General screen."If you do not assign a Default Server IP address, the ZyXEL Device discards all packets received for ports that are not specified here or in the remote management setup.Click Network > NAT > Port Forwarding to open the following screen. See Table 47 on page 134 for port numbers commonly used for particular services. SNMP trap 162PPTP (Point-to-Point Tunneling Protocol) 1723Table 47 Services and Port NumbersSERVICES PORT NUMBER

Chapter 8 Network Address Translation (NAT) ScreensP-660HW-Dx v2 User’s Guide136Figure 81 NAT Port ForwardingThe following table describes the fields in this screen. 8.6.1 Port Forwarding Rule Edit To edit a port forwarding rule, click the rule’s edit icon ( ) in the Port Forwarding screen to display the screen shown next. Table 48 NAT Port ForwardingLABEL DESCRIPTIONDefault Server SetupDefault Server In addition to the servers for specified services, NAT supports a default server. A default server receives packets from ports that are not specified in this screen. If you do not assign a Default Server IP address, the ZyXEL Device discards all packets received for ports that are not specified here or in the remote management setup.Port ForwardingService Name Select a service from the drop-down list box.Server IP AddressEnter the IP address of the server for the specified service.Add Click this button to add a rule to the table below.#This is the rule index number (read-only).Active Click this check box to enable the rule.Service Name This is a service’s name.Start Port This is the first port number that identifies a service.End Port This is the last port number that identifies a service.Server IP AddressThis is the server’s IP address.Modify Click the edit icon to go to the screen where you can edit the port forwarding rule.Click the delete icon to delete an existing port forwarding rule. Note that subsequent rules move up by one when you take this action.Apply Click Apply to save your changes to the ZyXEL Device.Cancel Click Cancel to return to the previous configuration.

Chapter 8 Network Address Translation (NAT) ScreensP-660HW-Dx v2 User’s Guide 137Figure 82 Port Forwarding Rule Setup The following table describes the fields in this screen. 8.7 Address Mapping "The Address Mapping screen is available only when you select Full Feature in the NAT > General screen.Ordering your rules is important because the ZyXEL Device applies the rules in the order that you specify. When a rule matches the current packet, the ZyXEL Device takes the corresponding action and the remaining rules are ignored. If there are any empty rules before your new configured rule, your configured rule will be pushed up by that number of empty Table 49 Port Forwarding Rule Setup LABEL DESCRIPTIONActive Click this check box to enable the rule.Service Name Enter a name to identify this port-forwarding rule.Start Port Enter a port number in this field. To forward only one port, enter the port number again in the End Port field. To forward a series of ports, enter the start port number here and the end port number in the End Port field.End Port Enter a port number in this field. To forward only one port, enter the port number again in the Start Port field above and then enter it again in this field. To forward a series of ports, enter the last port number in a series that begins with the port number in the Start Port field above.Server IP AddressEnter the inside IP address of the server here.Back Click Back to return to the previous screen.Apply Click Apply to save your changes to the ZyXEL Device.Cancel Click Cancel to begin configuring this screen afresh.

Chapter 8 Network Address Translation (NAT) ScreensP-660HW-Dx v2 User’s Guide138rules. For example, if you have already configured rules 1 to 6 in your current set and now you configure rule number 9. In the set summary screen, the new rule will be rule 7, not 9. Now if you delete rule 4, rules 5 to 7 will be pushed up by 1 rule, so old rules 5, 6 and 7 become new rules 4, 5 and 6. To change your ZyXEL Device’s address mapping settings, click Network > NAT > Address Mapping to open the following screen. Figure 83 Address Mapping RulesThe following table describes the fields in this screen. Table 50 Address Mapping RulesLABEL DESCRIPTION#This is the rule index number.Local Start IP This is the starting Inside Local IP Address (ILA). Local IP addresses are N/A for Server port mapping.Local End IP This is the end Inside Local IP Address (ILA). If the rule is for all local IP addresses, then this field displays 0.0.0.0 as the Local Start IP address and 255.255.255.255 as the Local End IP address. This field is N/A for One-to-one and Server mapping types.Global Start IP This is the starting Inside Global IP Address (IGA). Enter 0.0.0.0 here if you have a dynamic IP address from your ISP. You can only do this for Many-to-One and Server mapping types. Global End IP This is the ending Inside Global IP Address (IGA). This field is N/A for One-to-one, Many-to-One and Server mapping types.

Chapter 8 Network Address Translation (NAT) ScreensP-660HW-Dx v2 User’s Guide 1398.7.1 Address Mapping Rule Edit To edit an address mapping rule, click the rule’s edit icon in the Address Mapping screen to display the screen shown next. Figure 84 Edit Address Mapping Rule Type 1-1: One-to-one mode maps one local IP address to one global IP address. Note that port numbers do not change for the One-to-one NAT mapping type. M-1: Many-to-One mode maps multiple local IP addresses to one global IP address. This is equivalent to SUA (i.e., PAT, port address translation), ZyXEL's Single User Account feature that previous ZyXEL routers supported only. M-M Ov (Overload): Many-to-Many Overload mode maps multiple local IP addresses to shared global IP addresses. MM No (No Overload): Many-to-Many No Overload mode maps each local IP address to unique global IP addresses. Server: This type allows you to specify inside servers of different services behind the NAT to be accessible to the outside world. Modify Click the edit icon to go to the screen where you can edit the address mapping rule.Click the delete icon to delete an existing address mapping rule. Note that subsequent address mapping rules move up by one when you take this action.Table 50 Address Mapping Rules (continued)LABEL DESCRIPTION

Chapter 8 Network Address Translation (NAT) ScreensP-660HW-Dx v2 User’s Guide140The following table describes the fields in this screen. Table 51 Edit Address Mapping Rule LABEL DESCRIPTIONType Choose the port mapping type from one of the following. •One-to-One: One-to-One mode maps one local IP address to one global IP address. Note that port numbers do not change for One-to-one NAT mapping type.•Many-to-One: Many-to-One mode maps multiple local IP addresses to one global IP address. This is equivalent to SUA (i.e., PAT, port address translation), ZyXEL's Single User Account feature that previous ZyXEL routers supported only. •Many-to-Many Overload: Many-to-Many Overload mode maps multiple local IP addresses to shared global IP addresses. •Many-to-Many No Overload: Many-to-Many No Overload mode maps each local IP address to unique global IP addresses. •Server: This type allows you to specify inside servers of different services behind the NAT to be accessible to the outside world.Local Start IP This is the starting local IP address (ILA). Local IP addresses are N/A for Server port mapping.Local End IP This is the end local IP address (ILA). If your rule is for all local IP addresses, then enter 0.0.0.0 as the Local Start IP address and 255.255.255.255 as the Local End IP address. This field is N/A for One-to-One and Server mapping types.Global Start IP This is the starting global IP address (IGA). Enter 0.0.0.0 here if you have a dynamic IP address from your ISP. Global End IP This is the ending global IP address (IGA). This field is N/A for One-to-One, Many-to-One and Server mapping types.Server Mapping SetOnly available when Type is set to Server. Select a number from the drop-down menu to choose a server mapping set.Edit Details Click this link to go to the Port Forwarding screen to edit a server mapping set that you have selected in the Server Mapping Set field.Back Click Back to return to the previous screen.Apply Click Apply to save your changes to the ZyXEL Device.Cancel Click Cancel to begin configuring this screen afresh.

141PART IVSecurityFirewalls (143)Firewall Configuration (155)Content Filtering (177)Certificates (145)

142

P-660HW-Dx v2 User’s Guide 143CHAPTER 9 FirewallsThis chapter gives some background information on firewalls and introduces the ZyXEL Device firewall.9.1 Firewall Overview Originally, the term firewall referred to a construction technique designed to prevent the spread of fire from one room to another. The networking term “firewall” is a system or group of systems that enforces an access-control policy between two networks. It may also be defined as a mechanism used to protect a trusted network from an untrusted network. Of course, firewalls cannot solve every security problem. A firewall is one of the mechanisms used to establish a network security perimeter in support of a network security policy. It should never be the only mechanism or method employed. For a firewall to guard effectively, you must design and deploy it appropriately. This requires integrating the firewall into a broad information-security policy. In addition, specific policies must be implemented within the firewall itself. Refer to Section 10.5 on page 158 to configure default firewall settings. Refer to Section 10.6 on page 159 to view firewall rules. Refer to Section 10.6.1 on page 161 to configure firewall rules. Refer to Section 10.6.2 on page 164 to configure a custom service. Refer to Section 10.10.3 on page 173 to configure firewall thresholds. 9.2 Types of FirewallsThere are three main types of firewalls:• Packet Filtering Firewalls• Application-level Firewalls• Stateful Inspection Firewalls9.2.1 Packet Filtering FirewallsPacket filtering firewalls restrict access based on the source/destination computer network address of a packet and the type of application.

Chapter 9 FirewallsP-660HW-Dx v2 User’s Guide1449.2.2 Application-level FirewallsApplication-level firewalls restrict access by serving as proxies for external servers. Since they use programs written for specific Internet services, such as HTTP, FTP and telnet, they can evaluate network packets for valid application-specific data. Application-level gateways have a number of general advantages over the default mode of permitting application traffic directly to internal hosts:Information hiding prevents the names of internal systems from being made known via DNS to outside systems, since the application gateway is the only host whose name must be made known to outside systems.Robust authentication and logging pre-authenticates application traffic before it reaches internal hosts and causes it to be logged more effectively than if it were logged with standard host logging. Filtering rules at the packet filtering router can be less complex than they would be if the router needed to filter application traffic and direct it to a number of specific systems. The router need only allow application traffic destined for the application gateway and reject the rest.9.2.3 Stateful Inspection Firewalls Stateful inspection firewalls restrict access by screening data packets against defined access rules. They make access control decisions based on IP address and protocol. They also "inspect" the session data to assure the integrity of the connection and to adapt to dynamic protocols. These firewalls generally provide the best speed and transparency, however, they may lack the granular application level access control or caching that some proxies support. See Section 9.5 on page 148 for more information on stateful inspection.Firewalls, of one type or another, have become an integral part of standard security solutions for enterprises.9.3 Introduction to ZyXEL’s FirewallThe ZyXEL Device firewall is a stateful inspection firewall and is designed to protect against Denial of Service attacks when activated. The ZyXEL Device’s purpose is to allow a private Local Area Network (LAN) to be securely connected to the Internet. The ZyXEL Device can be used to prevent theft, destruction and modification of data, as well as log events, which may be important to the security of your network. The ZyXEL Device also has packet filtering capabilities.The ZyXEL Device is installed between the LAN and the Internet. This allows it to act as a secure gateway for all data passing between the Internet and the LAN.The ZyXEL Device has one DSL/ISDN port and one Ethernet LAN port, which physically separate the network into two areas.• The DSL/ISDN port connects to the Internet.• The LAN (Local Area Network) port attaches to a network of computers, which needs security from the outside world. These computers will have access to Internet services such as e-mail, FTP, and the World Wide Web. However, “inbound access” will not be allowed unless you configure remote management or create a firewall rule to allow a remote host to use a specific service.

Chapter 9 FirewallsP-660HW-Dx v2 User’s Guide 1459.3.1 Denial of Service AttacksFigure 85 Firewall Application9.4 Denial of ServiceDenials of Service (DoS) attacks are aimed at devices and networks with a connection to the Internet. Their goal is not to steal information, but to disable a device or network so users no longer have access to network resources. The ZyXEL Device is pre-configured to automatically detect and thwart all known DoS attacks.9.4.1 BasicsComputers share information over the Internet using a common language called TCP/IP. TCP/IP, in turn, is a set of application protocols that perform specific functions. An “extension number”, called the "TCP port" or "UDP port" identifies these protocols, such as HTTP (Web), FTP (File Transfer Protocol), POP3 (E-mail), etc. For example, Web traffic by default uses TCP port 80. When computers communicate on the Internet, they are using the client/server model, where the server "listens" on a specific TCP/UDP port for information requests from remote client computers on the network. For example, a Web server typically listens on port 80. Please note that while a computer may be intended for use over a single port, such as Web on port 80, other ports are also active. If the person configuring or managing the computer is not careful, a hacker could attack it over an unprotected port. Some of the most common IP ports are: Table 52 Common IP Ports21 FTP 53 DNS23 Telnet 80 HTTP25 SMTP 110 POP3

Chapter 9 FirewallsP-660HW-Dx v2 User’s Guide1469.4.2 Types of DoS AttacksThere are four types of DoS attacks: 1Those that exploit bugs in a TCP/IP implementation.2Those that exploit weaknesses in the TCP/IP specification.3Brute-force attacks that flood a network with useless data. 4IP Spoofing.5"Ping of Death" and "Teardrop" attacks exploit bugs in the TCP/IP implementations of various computer and host systems. • Ping of Death uses a "ping" utility to create an IP packet that exceeds the maximum 65,536 bytes of data allowed by the IP specification. The oversize packet is then sent to an unsuspecting system. Systems may crash, hang or reboot. • Teardrop attack exploits weaknesses in the re-assembly of IP packet fragments. As data is transmitted through a network, IP packets are often broken up into smaller chunks. Each fragment looks like the original IP packet except that it contains an offset field that says, for instance, "This fragment is carrying bytes 200 through 400 of the original (non fragmented) IP packet." The Teardrop program creates a series of IP fragments with overlapping offset fields. When these fragments are reassembled at the destination, some systems will crash, hang, or reboot. 6Weaknesses in the TCP/IP specification leave it open to "SYN Flood" and "LAND" attacks. These attacks are executed during the handshake that initiates a communication session between two applications.Figure 86 Three-Way HandshakeUnder normal circumstances, the application that initiates a session sends a SYN (synchronize) packet to the receiving server. The receiver sends back an ACK (acknowledgment) packet and its own SYN, and then the initiator responds with an ACK (acknowledgment). After this handshake, a connection is established. •SYN Attack floods a targeted system with a series of SYN packets. Each packet causes the targeted system to issue a SYN-ACK response. While the targeted system waits for the ACK that follows the SYN-ACK, it queues up all outstanding SYN-ACK responses on what is known as a backlog queue. SYN-ACKs are moved off the queue only when an ACK comes back or when an internal timer (which is set at relatively long intervals) terminates the three-way handshake. Once the queue is full, the system will ignore all incoming SYN requests, making the system unavailable for legitimate users.

Chapter 9 FirewallsP-660HW-Dx v2 User’s Guide 147Figure 87 SYN Flood•In a LAND Attack, hackers flood SYN packets into the network with a spoofed source IP address of the targeted system. This makes it appear as if the host computer sent the packets to itself, making the system unavailable while the target system tries to respond to itself. 7A brute-force attack, such as a "Smurf" attack, targets a feature in the IP specification known as directed or subnet broadcasting, to quickly flood the target network with useless data. A Smurf hacker floods a router with Internet Control Message Protocol (ICMP) echo request packets (pings). Since the destination IP address of each packet is the broadcast address of the network, the router will broadcast the ICMP echo request packet to all hosts on the network. If there are numerous hosts, this will create a large amount of ICMP echo request and response traffic. If a hacker chooses to spoof the source IP address of the ICMP echo request packet, the resulting ICMP traffic will not only clog up the "intermediary" network, but will also congest the network of the spoofed source IP address, known as the "victim" network. This flood of broadcast traffic consumes all available bandwidth, making communications impossible. Figure 88 Smurf Attack

Chapter 9 FirewallsP-660HW-Dx v2 User’s Guide1489.4.2.1 ICMP Vulnerability ICMP is an error-reporting protocol that works in concert with IP. The following ICMP types trigger an alert:9.4.2.2 Illegal Commands (NetBIOS and SMTP)The only legal NetBIOS commands are the following - all others are illegal.All SMTP commands are illegal except for those displayed in the following tables. 9.4.2.3 TracerouteTraceroute is a utility used to determine the path a packet takes between two endpoints. Sometimes when a packet filter firewall is configured incorrectly an attacker can traceroute the firewall gaining knowledge of the network topology inside the firewall.Often, many DoS attacks also employ a technique known as "IP Spoofing" as part of their attack. IP Spoofing may be used to break into systems, to hide the hacker's identity, or to magnify the effect of the DoS attack. IP Spoofing is a technique used to gain unauthorized access to computers by tricking a router or firewall into thinking that the communications are coming from within the trusted network. To engage in IP spoofing, a hacker must modify the packet headers so that it appears that the packets originate from a trusted host and should be allowed through the router or firewall. The ZyXEL Device blocks all IP Spoofing attempts.9.5 Stateful InspectionWith stateful inspection, fields of the packets are compared to packets that are already known to be trusted. For example, if you access some outside service, the proxy server remembers things about your original request, like the port number and source and destination addresses. This “remembering” is called saving the state. When the outside system responds to your request, the firewall compares the received packets with the saved state to determine if they Table 53 ICMP Commands That Trigger Alerts5REDIRECT13 TIMESTAMP_REQUEST14 TIMESTAMP_REPLY17 ADDRESS_MASK_REQUEST18 ADDRESS_MASK_REPLYTable 54 Legal NetBIOS CommandsMESSAGE:REQUEST:POSITIVE:VE:RETARGET:KEEPALIVE:Table 55 Legal SMTP CommandsAUTH DATA EHLO ETRN EXPN HELO HELP MAIL NOOPQUIT RCPT RSET SAML SEND SOML TURN VRFY

Chapter 9 FirewallsP-660HW-Dx v2 User’s Guide 149are allowed in. The ZyXEL Device uses stateful packet inspection to protect the private LAN from hackers and vandals on the Internet. By default, the ZyXEL Device’s stateful inspection allows all communications to the Internet that originate from the LAN, and blocks all traffic to the LAN that originates from the Internet. In summary, stateful inspection: • Allows all sessions originating from the LAN (local network) to the WAN (Internet).• Denies all sessions originating from the WAN to the LAN.Figure 89 Stateful InspectionThe previous figure shows the ZyXEL Device’s default firewall rules in action as well as demonstrates how stateful inspection works. User A can initiate a Telnet session from within the LAN and responses to this request are allowed. However other Telnet traffic initiated from the WAN is blocked.9.5.1 Stateful Inspection ProcessIn this example, the following sequence of events occurs when a TCP packet leaves the LAN network through the firewall's WAN interface. The TCP packet is the first in a session, and the packet's application layer protocol is configured for a firewall rule inspection:1The packet travels from the firewall's LAN to the WAN.2The packet is evaluated against the interface's existing outbound access list, and the packet is permitted (a denied packet would simply be dropped at this point).3The packet is inspected by a firewall rule to determine and record information about the state of the packet's connection. This information is recorded in a new state table entry created for the new connection. If there is not a firewall rule for this packet and it is not an attack, then the settings in the Firewall General screen determine the action for this packet.4Based on the obtained state information, a firewall rule creates a temporary access list entry that is inserted at the beginning of the WAN interface's inbound extended access list. This temporary access list entry is designed to permit inbound packets of the same connection as the outbound packet just inspected.5The outbound packet is forwarded out through the interface.

Chapter 9 FirewallsP-660HW-Dx v2 User’s Guide1506Later, an inbound packet reaches the interface. This packet is part of the connection previously established with the outbound packet. The inbound packet is evaluated against the inbound access list, and is permitted because of the temporary access list entry previously created.7The packet is inspected by a firewall rule, and the connection's state table entry is updated as necessary. Based on the updated state information, the inbound extended access list temporary entries might be modified, in order to permit only packets that are valid for the current state of the connection.8Any additional inbound or outbound packets that belong to the connection are inspected to update the state table entry and to modify the temporary inbound access list entries as required, and are forwarded through the interface.9When the connection terminates or times out, the connection's state table entry is deleted and the connection's temporary inbound access list entries are deleted.9.5.2 Stateful Inspection and the ZyXEL DeviceAdditional rules may be defined to extend or override the default rules. For example, a rule may be created which will:• Block all traffic of a certain type, such as IRC (Internet Relay Chat), from the LAN to the Internet.• Allow certain types of traffic from the Internet to specific hosts on the LAN.• Allow access to a Web server to everyone but competitors.• Restrict use of certain protocols, such as Telnet, to authorized users on the LAN.These custom rules work by evaluating the network traffic’s Source IP address, Destination IP address, IP protocol type, and comparing these to rules set by the administrator."The ability to define firewall rules is a very powerful tool. Using custom rules, it is possible to disable all firewall protection or block all access to the Internet. Use extreme caution when creating or deleting firewall rules. Test changes after creating them to make sure they work correctly.Below is a brief technical description of how these connections are tracked. Connections may either be defined by the upper protocols (for instance, TCP), or by the ZyXEL Device itself (as with the "virtual connections" created for UDP and ICMP). 9.5.3 TCP SecurityThe ZyXEL Device uses state information embedded in TCP packets. The first packet of any new connection has its SYN flag set and its ACK flag cleared; these are "initiation" packets. All packets that do not have this flag structure are called "subsequent" packets, since they represent data that occurs later in the TCP stream. If an initiation packet originates on the WAN, this means that someone is trying to make a connection from the Internet into the LAN. Except in a few special cases (see "Upper Layer Protocols" shown next), these packets are dropped and logged.

Chapter 9 FirewallsP-660HW-Dx v2 User’s Guide 151If an initiation packet originates on the LAN, this means that someone is trying to make a connection from the LAN to the Internet. Assuming that this is an acceptable part of the security policy (as is the case with the default policy), the connection will be allowed. A cache entry is added which includes connection information such as IP addresses, TCP ports, sequence numbers, etc.When the ZyXEL Device receives any subsequent packet (from the Internet or from the LAN), its connection information is extracted and checked against the cache. A packet is only allowed to pass through if it corresponds to a valid connection (that is, if it is a response to a connection which originated on the LAN).9.5.4 UDP/ICMP SecurityUDP and ICMP do not themselves contain any connection information (such as sequence numbers). However, at the very minimum, they contain an IP address pair (source and destination). UDP also contains port pairs, and ICMP has type and code information. All of this data can be analyzed in order to build "virtual connections" in the cache. For instance, any UDP packet that originates on the LAN will create a cache entry. Its IP address and port pairs will be stored. For a short period of time, UDP packets from the WAN that have matching IP and UDP information will be allowed back in through the firewall.A similar situation exists for ICMP, except that the ZyXEL Device is even more restrictive. Specifically, only outgoing echoes will allow incoming echo replies, outgoing address mask requests will allow incoming address mask replies, and outgoing timestamp requests will allow incoming timestamp replies. No other ICMP packets are allowed in through the firewall, simply because they are too dangerous and contain too little tracking information. For instance, ICMP redirect packets are never allowed in, since they could be used to reroute traffic through attacking machines. 9.5.5 Upper Layer ProtocolsSome higher layer protocols (such as FTP and RealAudio) utilize multiple network connections simultaneously. In general terms, they usually have a "control connection" which is used for sending commands between endpoints, and then "data connections" which are used for transmitting bulk information. Consider the FTP protocol. A user on the LAN opens a control connection to a server on the Internet and requests a file. At this point, the remote server will open a data connection from the Internet. For FTP to work properly, this connection must be allowed to pass through even though a connection from the Internet would normally be rejected.In order to achieve this, the ZyXEL Device inspects the application-level FTP data. Specifically, it searches for outgoing "PORT" commands, and when it sees these, it adds a cache entry for the anticipated data connection. This can be done safely, since the PORT command contains address and port information, which can be used to uniquely identify the connection.Any protocol that operates in this way must be supported on a case-by-case basis. You can use the web configurator’s Custom Ports feature to do this.

Chapter 9 FirewallsP-660HW-Dx v2 User’s Guide1529.6 Guidelines for Enhancing Security with Your Firewall• Change the default password via CLI (Command Line Interpreter) or web configurator. • Limit who can telnet into your router. • Don't enable any local service (such as SNMP or NTP) that you don't use. Any enabled service could present a potential security risk. A determined hacker might be able to find creative ways to misuse the enabled services to access the firewall or the network. • For local services that are enabled, protect against misuse. Protect by configuring the services to communicate only with specific peers, and protect by configuring rules to block packets for the services at specific interfaces. • Protect against IP spoofing by making sure the firewall is active. • Keep the firewall in a secured (locked) room. 9.6.1 Security In GeneralYou can never be too careful! Factors outside your firewall, filtering or NAT can cause security breaches. Below are some generalizations about what you can do to minimize them.• Encourage your company or organization to develop a comprehensive security plan. Good network administration takes into account what hackers can do and prepares against attacks. The best defense against hackers and crackers is information. Educate all employees about the importance of security and how to minimize risk. Produce lists like this one!• DSL or cable modem connections are “always-on” connections and are particularly vulnerable because they provide more opportunities for hackers to crack your system. Turn your computer off when not in use. • Never give out a password or any sensitive information to an unsolicited telephone call or e-mail.• Never e-mail sensitive information such as passwords, credit card information, etc., without encrypting the information first.• Never submit sensitive information via a web page unless the web site uses secure connections. You can identify a secure connection by looking for a small “key” icon on the bottom of your browser (Internet Explorer 3.02 or better or Netscape 3.0 or better). If a web site uses a secure connection, it is safe to submit information. Secure web transactions are quite difficult to crack.• Never reveal your IP address or other system networking information to people outside your company. Be careful of files e-mailed to you from strangers. One common way of getting BackOrifice on a system is to include it as a Trojan horse with other files.• Change your passwords regularly. Also, use passwords that are not easy to figure out. The most difficult passwords to crack are those with upper and lower case letters, numbers and a symbol such as % or #.• Upgrade your software regularly. Many older versions of software, especially web browsers, have well known security deficiencies. When you upgrade to the latest versions, you get the latest patches and fixes.• If you use “chat rooms” or IRC sessions, be careful with any information you reveal to strangers.• If your system starts exhibiting odd behavior, contact your ISP. Some hackers will set off hacks that cause your system to slowly become unstable or unusable.

Chapter 9 FirewallsP-660HW-Dx v2 User’s Guide 153• Always shred confidential information, particularly about your computer, before throwing it away. Some hackers dig through the trash of companies or individuals for information that might help them in an attack.9.7 Packet Filtering Vs FirewallBelow are some comparisons between the ZyXEL Device’s filtering and firewall functions.9.7.1 Packet Filtering:• The router filters packets as they pass through the router’s interface according to the filter rules you designed.• Packet filtering is a powerful tool, yet can be complex to configure and maintain, especially if you need a chain of rules to filter a service.• Packet filtering only checks the header portion of an IP packet.9.7.1.1 When To Use Filtering• To block/allow LAN packets by their MAC addresses.• To block/allow special IP packets which are neither TCP nor UDP, nor ICMP packets.• To block/allow both inbound (WAN to LAN) and outbound (LAN to WAN) traffic between the specific inside host/network "A" and outside host/network "B". If the filter blocks the traffic from A to B, it also blocks the traffic from B to A. Filters can not distinguish traffic originating from an inside host or an outside host by IP address.• To block/allow IP trace route.9.7.2 Firewall• The firewall inspects packet contents as well as their source and destination addresses. Firewalls of this type employ an inspection module, applicable to all protocols, that understands data in the packet is intended for other layers, from the network layer (IP headers) up to the application layer.• The firewall performs stateful inspection. It takes into account the state of connections it handles so that, for example, a legitimate incoming packet can be matched with the outbound request for that packet and allowed in. Conversely, an incoming packet masquerading as a response to a nonexistent outbound request can be blocked.• The firewall uses session filtering, i.e., smart rules, that enhance the filtering process and control the network session rather than control individual packets in a session.• The firewall provides e-mail service to notify you of routine reports and when alerts occur.9.7.2.1 When To Use The Firewall• To prevent DoS attacks and prevent hackers cracking your network.• A range of source and destination IP addresses as well as port numbers can be specified within one firewall rule making the firewall a better choice when complex rules are required.

Chapter 9 FirewallsP-660HW-Dx v2 User’s Guide154• To selectively block/allow inbound or outbound traffic between inside host/networks and outside host/networks. Remember that filters can not distinguish traffic originating from an inside host or an outside host by IP address.• The firewall performs better than filtering if you need to check many rules.• Use the firewall if you need routine e-mail reports about your system or need to be alerted when attacks occur.• The firewall can block specific URL traffic that might occur in the future. The URL can be saved in an Access Control List (ACL) database.

P-660HW-Dx v2 User’s Guide 155CHAPTER 10 Firewall ConfigurationThis chapter shows you how to enable and configure the ZyXEL Device firewall.10.1 Access MethodsThe web configurator is, by far, the most comprehensive firewall configuration tool your ZyXEL Device has to offer. For this reason, it is recommended that you configure your firewall using the web configurator.CLI (Command Line Interpreter) commands provide limited configuration options and are only recommended for advanced users.10.2 Firewall Policies Overview Firewall rules are grouped based on the direction of travel of packets to which they apply: By default, the ZyXEL Device’s stateful packet inspection allows packets traveling in the following directions:• LAN to LAN/ Router This allows computers on the LAN to manage the ZyXEL Device and communicate between networks or subnets connected to the LAN interface.• LAN to WANBy default, the ZyXEL Device’s stateful packet inspection drops packets traveling in the following directions:•WAN to LAN•WAN to WAN/ Router This prevents computers on the WAN from using the ZyXEL Device as a gateway to communicate with other computers on the WAN and/or managing the ZyXEL Device.You may define additional rules and sets or modify existing ones but please exercise extreme caution in doing so.• LAN to LAN/ Router • WAN to LAN• LAN to WAN • WAN to WAN/ Router

Chapter 10 Firewall ConfigurationP-660HW-Dx v2 User’s Guide156"If you configure firewall rules without a good understanding of how they work, you might inadvertently introduce security risks to the firewall and to the protected network. Make sure you test your rules after you configure them.For example, you may create rules to:• Block certain types of traffic, such as IRC (Internet Relay Chat), from the LAN to the Internet.• Allow certain types of traffic, such as Lotus Notes database synchronization, from specific hosts on the Internet to specific hosts on the LAN.• Allow everyone except your competitors to access a Web server.• Restrict use of certain protocols, such as Telnet, to authorized users on the LAN.These custom rules work by comparing the Source IP address, Destination IP address and IP protocol type of network traffic to rules set by the administrator. Your customized rules take precedence and override the ZyXEL Device’s default rules. 10.3 Rule Logic Overview "Study these points carefully before configuring rules.10.3.1 Rule ChecklistState the intent of the rule. For example, “This restricts all IRC access from the LAN to the Internet.” Or, “This allows a remote Lotus Notes server to synchronize over the Internet to an inside Notes server.”1Is the intent of the rule to forward or block traffic?2What direction of traffic does the rule apply to?3What IP services will be affected?4What computers on the LAN are to be affected (if any)?5What computers on the Internet will be affected? The more specific, the better. For example, if traffic is being allowed from the Internet to the LAN, it is better to allow only certain machines on the Internet to access the LAN.10.3.2 Security Ramifications1Once the logic of the rule has been defined, it is critical to consider the security ramifications created by the rule:2Does this rule stop LAN users from accessing critical resources on the Internet? For example, if IRC is blocked, are there users that require this service?

Chapter 10 Firewall ConfigurationP-660HW-Dx v2 User’s Guide 1573Is it possible to modify the rule to be more specific? For example, if IRC is blocked for all users, will a rule that blocks just certain users be more effective?4Does a rule that allows Internet users access to resources on the LAN create a security vulnerability? For example, if FTP ports (TCP 20, 21) are allowed from the Internet to the LAN, Internet users may be able to connect to computers with running FTP servers.5Does this rule conflict with any existing rules?6Once these questions have been answered, adding rules is simply a matter of plugging the information into the correct fields in the web configurator screens.10.3.3 Key Fields For Configuring Rules 10.3.3.1 ActionShould the action be to Drop, Reject or Permit? "“Drop” means the firewall silently discards the packet. “Reject” means the firewall discards packets and sends an ICMP destination-unreachable message to the sender.10.3.3.2 ServiceSelect the service from the Service scrolling list box. If the service is not listed, it is necessary to first define it. See Section 10.8 on page 169 for more information on predefined services.10.3.3.3 Source AddressWhat is the connection’s source address; is it on the LAN or WAN? Is it a single IP, a range of IPs or a subnet?10.3.3.4 Destination AddressWhat is the connection’s destination address; is it on the LAN or WAN? Is it a single IP, a range of IPs or a subnet?10.4 Connection DirectionThis section describes examples for firewall rules for connections going from LAN to WAN and from WAN to LAN.LAN to LAN/ Router and WAN to WAN/ Router rules apply to packets coming in on the associated interface (LAN or WAN respectively). LAN to LAN/ Router means policies for LAN-to-ZyXEL Device (the policies for managing the ZyXEL Device through the LAN interface) and policies for LAN-to-LAN (the policies that control routing between two subnets on the LAN). Similarly, WAN to WAN/ Router polices apply in the same way to the WAN port.

Chapter 10 Firewall ConfigurationP-660HW-Dx v2 User’s Guide15810.4.1 LAN to WAN RulesThe default rule for LAN to WAN traffic is that all users on the LAN are allowed non-restricted access to the WAN. When you configure a LAN to WAN rule, you in essence want to limit some or all users from accessing certain services on the WAN. WAN to LAN RulesThe default rule for WAN to LAN traffic blocks all incoming connections (WAN to LAN). If you wish to allow certain WAN users to have access to your LAN, you will need to create custom rules to allow it. 10.4.2 AlertsAlerts are reports on events, such as attacks, that you may want to know about right away. You can choose to generate an alert when a rule is matched in the Edit Rule screen (see Figure 92 on page 162). When an event generates an alert, a message can be immediately sent to an e-mail account that you specify in the Log Settings screen. Refer to the chapter on logs for details10.5 General Firewall Policy Click Security > Firewall to display the following screen. Activate the firewall by selecting the Active Firewall check box as seen in the following screen.Refer to Section 9.1 on page 143 for more information. Figure 90 Firewall: General

Chapter 10 Firewall ConfigurationP-660HW-Dx v2 User’s Guide 159The following table describes the labels in this screen. 10.6 Firewall Rules Summary "The ordering of your rules is very important as rules are applied in turn.Refer to Section 9.1 on page 143 for more information. Click Security > Firewall > Rules to bring up the following screen. This screen displays a list of the configured firewall rules. Note the order in which the rules are listed.Table 56 Firewall: GeneralLABEL DESCRIPTIONActive Firewall Select this check box to activate the firewall. The ZyXEL Device performs access control and protects against Denial of Service (DoS) attacks when the firewall is activated.Bypass Triangle RouteSelect this check box to have the ZyXEL Device firewall permit the use of triangle route topology on the network. See the appendix for more on triangle route topology.Note: Allowing asymmetrical routes may let traffic from the WAN go directly to a LAN computer without passing through the router. See Appendix I on page 341 for more on triangle route topology and how to deal with this problem.Packet Direction This is the direction of travel of packets (LAN to LAN / Router, LAN to WAN, WAN to WAN / Router, WAN to LAN).Firewall rules are grouped based on the direction of travel of packets to which they apply. For example, LAN to LAN / Router means packets traveling from a computer/subnet on the LAN to either another computer/subnet on the LAN interface of the ZyXEL Device or the ZyXEL Device itself. Default Action Use the drop-down list boxes to select the default action that the firewall is take on packets that are traveling in the selected direction and do not match any of the firewall rules. Select Drop to silently discard the packets without sending a TCP reset packet or an ICMP destination-unreachable message to the sender.Select Reject to deny the packets and send a TCP reset packet (for a TCP packet) or an ICMP destination-unreachable message (for a UDP packet) to the sender.Select Permit to allow the passage of the packets.Log Select the check box to create a log (when the above action is taken) for packets that are traveling in the selected direction and do not match any of your customized rules.Expand... Click this button to display more information.Basic... Click this button to display less information.Apply Click Apply to save your changes to the ZyXEL Device.Cancel Click Cancel to begin configuring this screen afresh.

Chapter 10 Firewall ConfigurationP-660HW-Dx v2 User’s Guide160Figure 91 Firewall Rules The following table describes the labels in this screen. Table 57 Firewall RulesLABEL DESCRIPTIONFirewall Rules Storage Space in UseThis read-only bar shows how much of the ZyXEL Device's memory for recording firewall rules it is currently using. When you are using 80% or less of the storage space, the bar is green. When the amount of space used is over 80%, the bar is red.Packet DirectionUse the drop-down list box to select a direction of travel of packets for which you want to configure firewall rules.Create a new rule after rule number Select an index number and click Add to add a new firewall rule after the selected index number. For example, if you select “6”, your new rule becomes number 7 and the previous rule 7 (if there is one) becomes rule 8.The following read-only fields summarize the rules you have created that apply to traffic traveling in the selected packet direction. The firewall rules that you configure (summarized below) take priority over the general firewall action settings in the General screen.#This is your firewall rule number. The ordering of your rules is important as rules are applied in turn. Active This field displays whether a firewall is turned on or not. Select the check box to enable the rule. Clear the check box to disable the rule.Source IP This drop-down list box displays the source addresses or ranges of addresses to which this firewall rule applies. Please note that a blank source or destination address is equivalent to Any.Destination IP This drop-down list box displays the destination addresses or ranges of addresses to which this firewall rule applies. Please note that a blank source or destination address is equivalent to Any.Service This drop-down list box displays the services to which this firewall rule applies. See Section 10.8 on page 169 for more information.Action This field displays whether the firewall silently discards packets (Drop), discards packets and sends a TCP reset packet or an ICMP destination-unreachable message to the sender (Reject) or allows the passage of packets (Permit)Schedule This field tells you whether a schedule is specified (Yes) or not (No).

Chapter 10 Firewall ConfigurationP-660HW-Dx v2 User’s Guide 16110.6.1 Configuring Firewall Rules Refer to Section 9.1 on page 143 for more information. In the Rules screen, select an index number and click Add or click a rule’s Edit icon to display this screen and refer to the following table for information on the labels.Log This field shows you whether a log is created when packets match this rule (Yes) or not (No).Modify Click the Edit icon to go to the screen where you can edit the rule.Click the Remove icon to delete an existing firewall rule. A window displays asking you to confirm that you want to delete the firewall rule. Note that subsequent firewall rules move up by one when you take this action.Order Click the Move icon to display the Move the rule to field. Type a number in the Move the rule to field and click the Move button to move the rule to the number that you typed. The ordering of your rules is important as they are applied in order of their numbering.Apply Click Apply to save your changes to the ZyXEL Device.Cancel Click Cancel to begin configuring this screen afresh.Table 57 Firewall Rules (continued)LABEL DESCRIPTION

Chapter 10 Firewall ConfigurationP-660HW-Dx v2 User’s Guide162Figure 92 Firewall: Edit Rule

Chapter 10 Firewall ConfigurationP-660HW-Dx v2 User’s Guide 163The following table describes the labels in this screen.Table 58 Firewall: Edit RuleLABEL DESCRIPTIONActive Select this option to enable this firewall rule. Action for Matched PacketUse the drop-down list box to select what the firewall is to do with packets that match this rule. Select Drop to silently discard the packets without sending a TCP reset packet or an ICMP destination-unreachable message to the sender.Select Reject to deny the packets and send a TCP reset packet (for a TCP packet) or an ICMP destination-unreachable message (for a UDP packet) to the sender.Select Permit to allow the passage of the packets. Source/Destination AddressAddress Type Do you want your rule to apply to packets with a particular (single) IP, a range of IP addresses (e.g., 192.168.1.10 to 192.169.1.50), a subnet or any IP address? Select an option from the drop-down list box that includes: Single Address, Range Address, Subnet Address and Any Address. Start IP Address Enter the single IP address or the starting IP address in a range here. End IP Address Enter the ending IP address in a range here.Subnet Mask Enter the subnet mask here, if applicable.Add >> Click Add >> to add a new address to the Source or Destination Address box. You can add multiple addresses, ranges of addresses, and/or subnets.Edit << To edit an existing source or destination address, select it from the box and click Edit <<.Delete Highlight an existing source or destination address from the Source or Destination Address box above and click Delete to remove it.ServicesAvailable/ Selected ServicesPlease see Section 10.8 on page 169 for more information on services available. Highlight a service from the Available Services box on the left, then click Add >> to add it to the Selected Services box on the right. To remove a service, highlight it in the Selected Services box on the right, then click Remove.Edit Customized ServiceClick the Edit Customized Services link to bring up the screen that you use to configure a new custom service that is not in the predefined list of services.ScheduleDay to Apply Select everyday or the day(s) of the week to apply the rule.Time of Day to Apply (24-Hour Format)Select All Day or enter the start and end times in the hour-minute format to apply the rule.LogLog Packet Detail Information This field determines if a log for packets that match the rule is created or not. Go to the Log Settings page and select the Access Control logs category to have the ZyXEL Device record these logs.Alert Send Alert Message to Administrator When MatchedSelect the check box to have the ZyXEL Device generate an alert when the rule is matched.

Chapter 10 Firewall ConfigurationP-660HW-Dx v2 User’s Guide16410.6.2 Customized Services Configure customized services and port numbers not predefined by the ZyXEL Device. For a comprehensive list of port numbers and services, visit the IANA (Internet Assigned Number Authority) website. For further information on these services, please read Section 10.8 on page 169. Click the Edit Customized Services link while editing a firewall rule to configure a custom service port. This displays the following screen.Refer to Section 9.1 on page 143 for more information. Figure 93 Firewall: Customized ServicesThe following table describes the labels in this screen. 10.6.3 Configuring a Customized Service Click a rule number in the Firewall Customized Services screen to create a new custom port or edit an existing one. This action displays the following screen.Apply Click Apply to save your customized settings and exit this screen.Cancel Click Cancel to exit this screen without saving.Table 58 Firewall: Edit Rule (continued)LABEL DESCRIPTIONTable 59 Customized ServicesLABEL DESCRIPTIONNo. This is the number of your customized port. Click a rule’s number of a service to go to a screen where you can configure or edit a customized service. See Section 10.6.3 on page 164 for more information.Name This is the name of your customized service.Protocol This shows the IP protocol (TCP, UDP or TCP/UDP) that defines your customized service.Port This is the port number or range that defines your customized service.Back Click Back to return the Firewall Edit Rule screen.

Chapter 10 Firewall ConfigurationP-660HW-Dx v2 User’s Guide 165Refer to Section 9.1 on page 143 for more information. Figure 94 Firewall: Configure Customized ServicesThe following table describes the labels in this screen.10.7 Example Firewall Rule The following Internet firewall rule example allows a hypothetical “MyService” connection from the Internet.1Click Security > Firewall > Rules.2Select WAN to LAN in the Packet Direction field. Table 60 Firewall: Configure Customized ServicesLABEL DESCRIPTIONService Name Type a unique name for your custom port.Service Type Choose the IP port (TCP, UDP or TCP/UDP) that defines your customized port from the drop down list box.Port ConfigurationType Click Single to specify one port only or Range to specify a span of ports that define your customized service. Port Number Type a single port number or the range of port numbers that define your customized service.Back Click Back to return to the previous screen.Apply Click Apply to save your customized settings and exit this screen.Cancel Click Cancel to return to the previous screen.Delete Click Delete to delete the current rule and return to the previous screen.

Chapter 10 Firewall ConfigurationP-660HW-Dx v2 User’s Guide166Figure 95 Firewall Example: Rules3In the Rules screen, select the index number after that you want to add the rule. For example, if you select “6”, your new rule becomes number 7 and the previous rule 7 (if there is one) becomes rule 8.4Click Add to display the firewall rule configuration screen.5In the Edit Rule screen, click the Edit Customized Services link to open the Customized Service screen. 6Click an index number to display the Customized Services Config screen and configure the screen as follows and click Apply.Figure 96 Edit Custom Port Example7Select Any in the Destination Address box and then click Delete.8Configure the destination address screen as follows and click Add.

Chapter 10 Firewall ConfigurationP-660HW-Dx v2 User’s Guide 167Figure 97 Firewall Example: Edit Rule: Destination Address 9Use the Add >> and Remove buttons between Available Services and Selected Services list boxes to configure it as follows. Click Apply when you are done."Custom services show up with an “*” before their names in the Services list box and the Rules list box.

Chapter 10 Firewall ConfigurationP-660HW-Dx v2 User’s Guide168Figure 98 Firewall Example: Edit Rule: Select Customized ServicesOn completing the configuration procedure for this Internet firewall rule, the Rules screen should look like the following.Rule 1 allows a “MyService” connection from the WAN to IP addresses 10.0.0.10 through 10.0.0.15 on the LAN.

Chapter 10 Firewall ConfigurationP-660HW-Dx v2 User’s Guide 169Figure 99 Firewall Example: Rules: MyService 10.8 Predefined ServicesThe Available Services list box in the Edit Rule screen (see Section 10.6.1 on page 161) displays all predefined services that the ZyXEL Device already supports. Next to the name of the service, two fields appear in brackets. The first field indicates the IP protocol type (TCP, UDP, or ICMP). The second field indicates the IP port number that defines the service. (Note that there may be more than one IP protocol type. For example, look at the default configuration labeled “(DNS)”. (UDP/TCP:53) means UDP port 53 and TCP port 53. Up to 128 entries are supported. Custom service ports may also be configured using the Edit Customized Services function discussed previously.Table 61 Predefined ServicesSERVICE DESCRIPTIONAIM/NEW_ICQ(TCP:5190) AOL’s Internet Messenger service, used as a listening port by ICQ.AUTH(TCP:113) Authentication protocol used by some servers.BGP(TCP:179) Border Gateway Protocol.BOOTP_CLIENT(UDP:68) DHCP Client.BOOTP_SERVER(UDP:67) DHCP Server.CU-SEEME(TCP/UDP:7648, 24032) A popular videoconferencing solution from White Pines Software.DNS(UDP/TCP:53) Domain Name Server, a service that matches web names (e.g. www.zyxel.com) to IP numbers.FINGER(TCP:79) Finger is a UNIX or Internet related command that can be used to find out if a user is logged on.FTP(TCP:20.21) File Transfer Program, a program to enable fast transfer of files, including large files that may not be possible by e-mail.H.323(TCP:1720) Net Meeting uses this protocol.

Chapter 10 Firewall ConfigurationP-660HW-Dx v2 User’s Guide170HTTP(TCP:80) Hyper Text Transfer Protocol - a client/server protocol for the world wide web.HTTPS HTTPS is a secured http session often used in e-commerce.ICQ(UDP:4000) This is a popular Internet chat program.IPSEC_TRANSPORT/TUNNEL(AH:0)The IPSEC AH (Authentication Header) tunneling protocol uses this service.IPSEC_TUNNEL(ESP:0) The IPSEC ESP (Encapsulation Security Protocol) tunneling protocol uses this service.IRC(TCP/UDP:6667) This is another popular Internet chat program.MSN Messenger(TCP:1863) Microsoft Networks’ messenger service uses this protocol. MULTICAST(IGMP:0) Internet Group Multicast Protocol is used when sending packets to a specific group of hosts.NEWS(TCP:144) A protocol for news groups.NFS(UDP:2049) Network File System - NFS is a client/server distributed file service that provides transparent file-sharing for network environments.NNTP(TCP:119) Network News Transport Protocol is the delivery mechanism for the USENET newsgroup service.PING(ICMP:0) Packet INternet Groper is a protocol that sends out ICMP echo requests to test whether or not a remote host is reachable.POP3(TCP:110) Post Office Protocol version 3 lets a client computer get e-mail from a POP3 server through a temporary connection (TCP/IP or other).PPTP(TCP:1723) Point-to-Point Tunneling Protocol enables secure transfer of data over public networks. This is the control channel.PPTP_TUNNEL(GRE:0) Point-to-Point Tunneling Protocol enables secure transfer of data over public networks. This is the data channel.RCMD(TCP:512) Remote Command Service.REAL_AUDIO(TCP:7070) A streaming audio service that enables real time sound over the web.REXEC(TCP:514) Remote Execution Daemon.RLOGIN(TCP:513) Remote Login.RTELNET(TCP:107) Remote Telnet.RTSP(TCP/UDP:554) The Real Time Streaming (media control) Protocol (RTSP) is a remote control for multimedia on the Internet. SFTP(TCP:115) Simple File Transfer Protocol.SMTP(TCP:25) Simple Mail Transfer Protocol is the message-exchange standard for the Internet. SMTP enables you to move messages from one e-mail server to another.SNMP(TCP/UDP:161) Simple Network Management Program.SNMP-TRAPS (TCP/UDP:162) Traps for use with the SNMP (RFC:1215).SQL-NET(TCP:1521) Structured Query Language is an interface to access data on many different types of database systems, including mainframes, midrange systems, UNIX systems and network servers.SSDP(UDP:1900) Simole Service Discovery Protocol (SSDP) is a discovery service searching for Universal Plug and Play devices on your home network or upstream Internet gateways using DUDP port 1900. Table 61 Predefined Services (continued)SERVICE DESCRIPTION

Chapter 10 Firewall ConfigurationP-660HW-Dx v2 User’s Guide 17110.9 Anti-Probing If an outside user attempts to probe an unsupported port on your ZyXEL Device, an ICMP response packet is automatically returned. This allows the outside user to know the ZyXEL Device exists. The ZyXEL Device supports anti-probing, which prevents the ICMP response packet from being sent. This keeps outsiders from discovering your ZyXEL Device when unsupported ports are probed. Internet Control Message Protocol (ICMP) is a message control and error-reporting protocol between a host server and a gateway to the Internet. ICMP uses Internet Protocol (IP) datagrams, but the messages are processed by the TCP/IP software and directly apparent to the application user. Refer to Section 9.1 on page 143 for more information. Click Security > Firewall > Anti Probing to display the screen as shown. Figure 100 Firewall: Anti ProbingSSH(TCP/UDP:22) Secure Shell Remote Login Program.STRMWORKS(UDP:1558) Stream Works Protocol.SYSLOG(UDP:514) Syslog allows you to send system logs to a UNIX server.TACACS(UDP:49) Login Host Protocol used for (Terminal Access Controller Access Control System).TELNET(TCP:23) Telnet is the login and terminal emulation protocol common on the Internet and in UNIX environments. It operates over TCP/IP networks. Its primary function is to allow users to log into remote host systems.TFTP(UDP:69) Trivial File Transfer Protocol is an Internet file transfer protocol similar to FTP, but uses the UDP (User Datagram Protocol) rather than TCP (Transmission Control Protocol).VDOLIVE(TCP:7000) Another videoconferencing solution.Table 61 Predefined Services (continued)SERVICE DESCRIPTION

Chapter 10 Firewall ConfigurationP-660HW-Dx v2 User’s Guide172The following table describes the labels in this screen.10.10 DoS Thresholds For DoS attacks, the ZyXEL Device uses thresholds to determine when to drop sessions that do not become fully established. These thresholds apply globally to all sessions.You can use the default threshold values, or you can change them to values more suitable to your security requirements.Refer to Section 10.10.3 on page 173 to configure thresholds. 10.10.1 Threshold ValuesTune these parameters when something is not working and after you have checked the firewall counters. These default values should work fine for most small offices. Factors influencing choices for threshold values are:• The maximum number of opened sessions.• The minimum capacity of server backlog in your LAN network.• The CPU power of servers in your LAN network.• Network bandwidth. • Type of traffic for certain servers.If your network is slower than average for any of these factors (especially if you have servers that are slow or handle many tasks and are often busy), then the default values should be reduced.You should make any changes to the threshold values before you continue configuring firewall rules. Table 62 Firewall: Anti ProbingLABEL DESCRIPTIONRespond to PING onThe ZyXEL Device does not respond to any incoming Ping requests when Disable is selected. Select LAN to reply to incoming LAN Ping requests.Select WAN to reply to incoming WAN Ping requests. Otherwise select LAN & WAN to reply to both incoming LAN and WAN Ping requests. Do Not Respond to Requests for Unauthorized Services.Select this option to prevent hackers from finding the ZyXEL Device by probing for unused ports. If you select this option, the ZyXEL Device will not respond to port request(s) for unused ports, thus leaving the unused ports and the ZyXEL Device unseen. By default this option is not selected and the ZyXEL Device will reply with an ICMP Port Unreachable packet for a port probe on its unused UDP ports, and a TCP Reset packet for a port probe on its unused TCP ports. Note that the probing packets must first traverse the ZyXEL Device's firewall mechanism before reaching this anti-probing mechanism. Therefore if the firewall mechanism blocks a probing packet, the ZyXEL Device reacts based on the corresponding firewall policy to send a TCP reset packet for a blocked TCP packet or an ICMP port-unreachable packet for a blocked UDP packets or just drop the packets without sending a response packet.Apply Click Apply to save your changes to the ZyXEL Device.Cancel Click Cancel to begin configuring this screen afresh.

Chapter 10 Firewall ConfigurationP-660HW-Dx v2 User’s Guide 17310.10.2 Half-Open SessionsAn unusually high number of half-open sessions (either an absolute number or measured as the arrival rate) could indicate that a Denial of Service attack is occurring. For TCP, "half-open" means that the session has not reached the established state-the TCP three-way handshake has not yet been completed (see Figure 86 on page 146). For UDP, "half-open" means that the firewall has detected no return traffic.The ZyXEL Device measures both the total number of existing half-open sessions and the rate of session establishment attempts. Both TCP and UDP half-open sessions are counted in the total number and rate measurements. Measurements are made once a minute.When the number of existing half-open sessions rises above a threshold (max-incomplete high), the ZyXEL Device starts deleting half-open sessions as required to accommodate new connection requests. The ZyXEL Device continues to delete half-open requests as necessary, until the number of existing half-open sessions drops below another threshold (max-incomplete low).When the rate of new connection attempts rises above a threshold (one-minute high), the ZyXEL Device starts deleting half-open sessions as required to accommodate new connection requests. The ZyXEL Device continues to delete half-open sessions as necessary, until the rate of new connection attempts drops below another threshold (one-minute low). The rate is the number of new attempts detected in the last one-minute sample period.10.10.2.1 TCP Maximum Incomplete and Blocking TimeAn unusually high number of half-open sessions with the same destination host address could indicate that a Denial of Service attack is being launched against the host. Whenever the number of half-open sessions with the same destination host address rises above a threshold (TCP Maximum Incomplete), the ZyXEL Device starts deleting half-open sessions according to one of the following methods:• If the Blocking Time timeout is 0 (the default), then the ZyXEL Device deletes the oldest existing half-open session for the host for every new connection request to the host. This ensures that the number of half-open sessions to a given host will never exceed the threshold. • If the Blocking Time timeout is greater than 0, then the ZyXEL Device blocks all new connection requests to the host giving the server time to handle the present connections. The ZyXEL Device continues to block all new connection requests until the Blocking Time expires. 10.10.3 Configuring Firewall Thresholds The ZyXEL Device also sends alerts whenever TCP Maximum Incomplete is exceeded. The global values specified for the threshold and timeout apply to all TCP connections. Click Firewall, and Threshold to bring up the next screen.

Chapter 10 Firewall ConfigurationP-660HW-Dx v2 User’s Guide174Figure 101 Firewall: ThresholdThe following table describes the labels in this screen.Table 63 Firewall: ThresholdLABEL DESCRIPTION DEFAULT VALUESDenial of Service ThresholdsOne Minute Low This is the rate of new half-open sessions that causes the firewall to stop deleting half-open sessions. The ZyXEL Device continues to delete half-open sessions as necessary, until the rate of new connection attempts drops below this number.80 existing half-open sessions.One Minute High This is the rate of new half-open sessions that causes the firewall to start deleting half-open sessions. When the rate of new connection attempts rises above this number, the ZyXEL Device deletes half-open sessions as required to accommodate new connection attempts.100 half-open sessions per minute. The above numbers cause the ZyXEL Device to start deleting half-open sessions when more than 100 session establishment attempts have been detected in the last minute, and to stop deleting half-open sessions when fewer than 80 session establishment attempts have been detected in the last minute.Maximum Incomplete LowThis is the number of existing half-open sessions that causes the firewall to stop deleting half-open sessions. The ZyXEL Device continues to delete half-open requests as necessary, until the number of existing half-open sessions drops below this number.80 existing half-open sessions.

Chapter 10 Firewall ConfigurationP-660HW-Dx v2 User’s Guide 175Maximum Incomplete HighThis is the number of existing half-open sessions that causes the firewall to start deleting half-open sessions. When the number of existing half-open sessions rises above this number, the ZyXEL Device deletes half-open sessions as required to accommodate new connection requests. Do not set Maximum Incomplete High to lower than the current Maximum Incomplete Low number.100 existing half-open sessions. The above values causes the ZyXEL Device to start deleting half-open sessions when the number of existing half-open sessions rises above 100, and to stop deleting half-open sessions with the number of existing half-open sessions drops below 80.TCP Maximum Incomplete This is the number of existing half-open TCP sessions with the same destination host IP address that causes the firewall to start dropping half-open sessions to that same destination host IP address. Enter a number between 1 and 256. As a general rule, you should choose a smaller number for a smaller network, a slower system or limited bandwidth.10 existing half-open TCP sessions.Action taken when the TCP Maximum Incomplete threshold is reached.Delete the oldest half open session when new connection request comesSelect this radio button to clear the oldest half open session when a new connection request comes.Deny new connection request forSelect this radio button and specify for how long the ZyXEL Device should block new connection requests when TCP Maximum Incomplete is reached. Enter the length of blocking time in minutes (between 1 and 256).Apply Click Apply to save your changes to the ZyXEL Device.Cancel Click Cancel to begin configuring this screen afresh.Table 63 Firewall: Threshold (continued)LABEL DESCRIPTION DEFAULT VALUES

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P-660HW-Dx v2 User’s Guide 177CHAPTER 11 Content FilteringThis chapter covers how to configure content filtering.11.1 Content Filtering Overview Internet content filtering allows you to create and enforce Internet access policies tailored to your needs. Content filtering gives you the ability to block web sites that contain key words (that you specify) in the URL. You can set a schedule for when the ZyXEL Device performs content filtering. You can also specify trusted IP addresses on the LAN for which the ZyXEL Device will not perform content filtering.11.2 Configuring Keyword Blocking Use this screen to block sites containing certain keywords in the URL. For example, if you enable the keyword "bad", the ZyXEL Device blocks all sites containing this keyword including the URL http://www.website.com/bad.html, even if it is not included in the Filter List. To have your ZyXEL Device block Web sites containing keywords in their URLs, click Security > Content Filter. The screen appears as shown.Figure 102 Content Filter: Keyword

Chapter 11 Content FilteringP-660HW-Dx v2 User’s Guide178The following table describes the labels in this screen. 11.3 Configuring the Schedule To set the days and times for the ZyXEL Device to perform content filtering, click Security > Content Filter > Schedule. The screen appears as shown.Figure 103 Content Filter: ScheduleTable 64 Content Filter: KeywordLABEL DESCRIPTIONActive Keyword Blocking Select this check box to enable this feature.Block Websites that contain these keywords in the URL:This box contains the list of all the keywords that you have configured the ZyXEL Device to block. Delete Highlight a keyword in the box and click Delete to remove it. Clear All Click Clear All to remove all of the keywords from the list.Keyword Type a keyword in this field. You may use any character (up to 127 characters). Wildcards are not allowed.Add Keyword Click Add Keyword after you have typed a keyword. Repeat this procedure to add other keywords. Up to 64 keywords are allowed.When you try to access a web page containing a keyword, you will get a message telling you that the content filter is blocking this request.Apply Click Apply to save your changes to the ZyXEL Device.Cancel Click Cancel to return to the previously saved settings.

Chapter 11 Content FilteringP-660HW-Dx v2 User’s Guide 179The following table describes the labels in this screen. 11.4 Configuring Trusted Computers To exclude a range of users on the LAN from content filtering on your ZyXEL Device, click Security > Content Filter > Trusted. The screen appears as shown.Figure 104 Content Filter: TrustedThe following table describes the labels in this screen. Table 65 Content Filter: ScheduleLABEL DESCRIPTIONSchedule Select Active Everyday to Block to make the content filtering active everyday.Otherwise, select Edit Daily to Block and configure which days of the week (or everyday) and which time of the day you want the content filtering to be active. Active Everyday to BlockSelect this option to allow continuous filtering of websites based on the keywords you have chosen.Edit Daily to BlockSelect this option to filter websites according to the day(s) and time(s) configured.Active Select the check box to have the content filtering active on the selected day.Start TIme Enter the start time when you want the content filtering to take effect in hour-minute format.End Time Enter the end time when you want the content filtering to stop in hour-minute format. Apply Click Apply to save your changes. Cancel Click Cancel to return to the previously saved settings.Table 66 Content Filter: TrustedLABEL DESCRIPTIONTrusted User IP RangeFrom Type the IP address of a computer (or the beginning IP address of a specific range of computers) on the LAN that you want to exclude from content filtering. To Type the ending IP address of a specific range of users on your LAN that you want to exclude from content filtering. Leave this field blank if you want to exclude an individual computer.Apply Click Apply to save your changes to the ZyXEL Device. Cancel Click Cancel to return to the previously saved settings.

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181PART VAdvancedStatic Route (183)Bandwidth Management (187)Dynamic DNS Setup (199)Remote Management Configuration (203)Universal Plug-and-Play (UPnP) (213)

182

P-660HW-Dx v2 User’s Guide 183CHAPTER 12 Static RouteThis chapter shows you how to configure static routes for your ZyXEL Device.12.1 Static Route Each remote node specifies only the network to which the gateway is directly connected, and the ZyXEL Device has no knowledge of the networks beyond. For instance, the ZyXEL Device knows about network N2 in the following figure through remote node Router 1. However, the ZyXEL Device is unable to route a packet to network N3 because it doesn't know that there is a route through the same remote node Router 1 (via gateway Router 2). The static routes are for you to tell the ZyXEL Device about the networks beyond the remote nodes.Figure 105 Example of Static Routing Topology12.2 Configuring Static Route Click Advanced > Static Route to open the Static Route screen.

Chapter 12 Static RouteP-660HW-Dx v2 User’s Guide184Figure 106 Static RouteThe following table describes the labels in this screen. 12.2.1 Static Route Edit Select a static route index number and click Edit ( ). The screen shown next appears. Use this screen to configure the required information for a static route.Table 67 Static RouteLABEL DESCRIPTION#This is the number of an individual static route.Active Select the check box to activate this static route. Otherwise, clear the check box.Name This is the name that describes or identifies this route. Destination This parameter specifies the IP network address of the final destination. Routing is always based on network number. Gateway This is the IP address of the gateway. The gateway is a router or switch on the same network segment as the device's LAN or WAN port. The gateway helps forward packets to their destinations.Subnet Mask This is the IP subnet mask.Modify Click the Edit icon to go to the screen where you can set up a static route on the ZyXEL Device.Click the Delete icon to remove a static route from the ZyXEL Device. A window displays asking you to confirm that you want to delete the route.

Chapter 12 Static RouteP-660HW-Dx v2 User’s Guide 185Figure 107 Static Route EditThe following table describes the labels in this screen. Table 68 Static Route EditLABEL DESCRIPTIONActive This field allows you to activate/deactivate this static route.Route Name Enter the name of the IP static route. Leave this field blank to delete this static route.Destination IP AddressThis parameter specifies the IP network address of the final destination. Routing is always based on network number. If you need to specify a route to a single host, use a subnet mask of 255.255.255.255 in the subnet mask field to force the network number to be identical to the host ID.IP Subnet Mask Enter the IP subnet mask here.Gateway IP AddressEnter the IP address of the gateway. The gateway is a router or switch on the same network segment as the device's LAN or WAN port. The gateway helps forward packets to their destinations.Back Click Back to return to the previous screen without saving.Apply Click Apply to save your changes to the ZyXEL Device.Cancel Click Cancel to begin configuring this screen afresh.

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P-660HW-Dx v2 User’s Guide 187CHAPTER 13 Bandwidth ManagementThis chapter contains information about configuring bandwidth management, editing rules and viewing the ZyXEL Device’s bandwidth management logs.13.1 Bandwidth Management Overview ZyXEL’s Bandwidth Management allows you to specify bandwidth management rules based on an application and/or subnet. You can allocate specific amounts of bandwidth capacity (bandwidth budgets) to different bandwidth rules. The ZyXEL Device applies bandwidth management to traffic that it forwards out through an interface. The ZyXEL Device does not control the bandwidth of traffic that comes into an interface.Bandwidth management applies to all traffic flowing out of the router, regardless of the traffic's source.Traffic redirect or IP alias may cause LAN-to-LAN traffic to pass through the ZyXEL Device and be managed by bandwidth management. The sum of the bandwidth allotments that apply to any interface must be less than or equal to the speed allocated to that interface in the Bandwidth Management > Summary screen.13.2 Application-based Bandwidth ManagementYou can create bandwidth classes based on individual applications (like VoIP, Web, FTP, E-mail and Video for example).13.3 Subnet-based Bandwidth ManagementYou can create bandwidth classes based on subnets.The following figure shows LAN subnets. You could configure one bandwidth class for subnet A and another for subnet B.

Chapter 13 Bandwidth ManagementP-660HW-Dx v2 User’s Guide188Figure 108 Subnet-based Bandwidth Management Example13.4 Application and Subnet-based Bandwidth ManagementYou could also create bandwidth classes based on a combination of a subnet and an application. The following example table shows bandwidth allocations for application specific traffic from separate LAN subnets.13.5 SchedulerThe scheduler divides up an interface’s bandwidth among the bandwidth classes. The ZyXEL Device has two types of scheduler: fairness-based and priority-based. 13.5.1 Priority-based SchedulerWith the priority-based scheduler, the ZyXEL Device forwards traffic from bandwidth classes according to the priorities that you assign to the bandwidth classes. The larger a bandwidth class’s priority number is, the higher the priority. Assign real-time applications (like those using audio or video) a higher priority number to provide smoother operation.Table 69 Application and Subnet-based Bandwidth Management Example TRAFFIC TYPE FROM SUBNET A FROM SUBNET BVoIP 64 Kbps 64 KbpsWeb 64 Kbps 64 KbpsFTP 64 Kbps 64 KbpsE-mail 64 Kbps 64 KbpsVideo 64 Kbps 64 Kbps

Chapter 13 Bandwidth ManagementP-660HW-Dx v2 User’s Guide 18913.5.2 Fairness-based SchedulerThe ZyXEL Device divides bandwidth equally among bandwidth classes when using the fairness-based scheduler; thus preventing one bandwidth class from using all of the interface’s bandwidth. 13.6 Maximize Bandwidth UsageThe maximize bandwidth usage option (see Figure 109 on page 192) allows the ZyXEL Device to divide up any available bandwidth on the interface (including unallocated bandwidth and any allocated bandwidth that a class is not using) among the bandwidth classes that require more bandwidth. When you enable maximize bandwidth usage, the ZyXEL Device first makes sure that each bandwidth class gets up to its bandwidth allotment. Next, the ZyXEL Device divides up an interface’s available bandwidth (bandwidth that is unbudgeted or unused by the classes) depending on how many bandwidth classes require more bandwidth and on their priority levels. When only one class requires more bandwidth, the ZyXEL Device gives extra bandwidth to that class. When multiple classes require more bandwidth, the ZyXEL Device gives the highest priority classes the available bandwidth first (as much as they require, if there is enough available bandwidth), and then to lower priority classes if there is still bandwidth available. The ZyXEL Device distributes the available bandwidth equally among classes with the same priority level. 13.6.1 Reserving Bandwidth for Non-Bandwidth Class TrafficDo the following three steps to configure the ZyXEL Device to allow bandwidth for traffic that is not defined in a bandwidth filter.1Leave some of the interface’s bandwidth unbudgeted.2Do not enable the interface’s Maximize Bandwidth Usage option.3Do not enable bandwidth borrowing on the child-classes that have the root class as their parent (see Section 13.9 on page 192).13.6.2 Maximize Bandwidth Usage ExampleHere is an example of a ZyXEL Device that has maximize bandwidth usage enabled on an interface. The following table shows each bandwidth class’s bandwidth budget. The classes are set up based on subnets. The interface is set to 10240 kbps. Each subnet is allocated 2048 kbps. The unbudgeted 2048 kbps allows traffic not defined in any of the bandwidth filters to go out when you do not select the maximize bandwidth option.Table 70 Maximize Bandwidth Usage ExampleBANDWIDTH CLASSES AND ALLOTMENTSRoot Class: 10240 kbps Administration: 2048 kbpsSales: 2048 kbpsMarketing: 2048 kbpsResearch: 2048 kbps

Chapter 13 Bandwidth ManagementP-660HW-Dx v2 User’s Guide190The ZyXEL Device divides up the unbudgeted 2048 kbps among the classes that require more bandwidth. If the administration department only uses 1024 kbps of the budgeted 2048 kbps, the ZyXEL Device also divides the remaining 1024 kbps among the classes that require more bandwidth. Therefore, the ZyXEL Device divides a total of 3072 kbps of unbudgeted and unused bandwidth among the classes that require more bandwidth. 13.6.2.1 Priority-based Allotment of Unused and Unbudgeted BandwidthThe following table shows the priorities of the bandwidth classes and the amount of bandwidth that each class gets.Suppose that all of the classes except for the administration class need more bandwidth.• Each class gets up to its budgeted bandwidth. The administration class only uses 1024 kbps of its budgeted 2048 kbps. • The sales and marketing are first to get extra bandwidth because they have the highest priority (6). If they each require 1536 kbps or more of extra bandwidth, the ZyXEL Device divides the total 3072 kbps total of unbudgeted and unused bandwidth equally between the sales and marketing departments (1536 kbps extra to each for a total of 3584 kbps for each) because they both have the highest priority level. • Research requires more bandwidth but only gets its budgeted 2048 kbps because all of the unbudgeted and unused bandwidth goes to the higher priority sales and marketing classes. 13.6.2.2 Fairness-based Allotment of Unused and Unbudgeted BandwidthThe following table shows the amount of bandwidth that each class gets.Suppose that all of the classes except for the administration class need more bandwidth.• Each class gets up to its budgeted bandwidth. The administration class only uses 1024 kbps of its budgeted 2048 kbps. • The ZyXEL Device divides the total 3072 kbps total of unbudgeted and unused bandwidth equally among the other classes. 1024 kbps extra goes to each so the other classes each get a total of 3072 kbps. Table 71 Priority-based Allotment of Unused and Unbudgeted Bandwidth ExampleBANDWIDTH CLASSES, PRIORITIES AND ALLOTMENTSRoot Class: 10240 kbps Administration: Priority 4, 1024 kbpsSales: Priority 6, 3584 kbpsMarketing: Priority 6, 3584 kbpsResearch: Priority 5, 2048 kbpsTable 72 Fairness-based Allotment of Unused and Unbudgeted Bandwidth ExampleBANDWIDTH CLASSES AND ALLOTMENTSRoot Class: 10240 kbps Administration: 1024 kbpsSales: 3072 kbpsMarketing: 3072 kbpsResearch: 3072 kbps

Chapter 13 Bandwidth ManagementP-660HW-Dx v2 User’s Guide 19113.6.3 Bandwidth Management PrioritiesThe following table describes the priorities that you can apply to traffic that the ZyXEL Device forwards out through an interface.13.7 Over Allotment of BandwidthYou can set the bandwidth management speed for an interface higher than the interface’s actual transmission speed. Higher priority traffic gets to use up to its allocated bandwidth, even if it takes up all of the interface’s available bandwidth. This could stop lower priority traffic from being sent. The following is an example.If you use VoIP and NetMeeting at the same time, the device allocates up to 500 Kbps of bandwidth to each of them before it allocates any bandwidth to FTP. As a result, FTP can only use bandwidth when VoIP and NetMeeting do not use all of their allocated bandwidth.Suppose you try to browse the web too. In this case, VoIP, NetMeeting and FTP all have higher priority, so they get to use the bandwidth first. You can only browse the web when VoIP, NetMeeting, and FTP do not use all 1000 Kbps of available bandwidth.13.8 Configuring Summary Click Advanced > Bandwidth MGMT to open the screen as shown next. Enable bandwidth management on an interface and set the maximum allowed bandwidth for that interface. Table 73 Bandwidth Management PrioritiesPRIORITY LEVELS: TRAFFIC WITH A HIGHER PRIORITY GETS THROUGH FASTER WHILE TRAFFIC WITH A LOWER PRIORITY IS DROPPED IF THE NETWORK IS CONGESTED.High Typically used for voice traffic or video that is especially sensitive to jitter (jitter is the variations in delay).Mid Typically used for “excellent effort” or better than best effort and would include important business traffic that can tolerate some delay.Low This is typically used for non-critical “background” traffic such as bulk transfers that are allowed but that should not affect other applications and users. Table 74 Over Allotment of Bandwidth ExampleBANDWIDTH CLASSES, ALLOTMENTS PRIORITIESActual outgoing bandwidth available on the interface: 1000 kbpsRoot Class: 1500 kbps (same as Speed setting)VoIP traffic (Service = SIP): 500 Kbps HighNetMeeting traffic (Service = H.323): 500 kbps HighFTP (Service = FTP): 500 Kbps Medium

Chapter 13 Bandwidth ManagementP-660HW-Dx v2 User’s Guide192Figure 109 Bandwidth Management: SummaryThe following table describes the labels in this screen. 13.9 Bandwidth Management Rule Setup You must use the Bandwidth Management Summary screen to enable bandwidth management on an interface before you can configure rules for that interface.Table 75 Media Bandwidth Management: SummaryLABEL DESCRIPTIONInterface These read-only labels represent the physical interfaces. Select an interface’s check box to enable bandwidth management on that interface. Bandwidth management applies to all traffic flowing out of the router through the interface, regardless of the traffic’s source.Traffic redirect or IP alias may cause LAN-to-LAN traffic to pass through the ZyXEL Device and be managed by bandwidth management.Active Select an interface’s check box to enable bandwidth management on that interface. Speed (kbps) Enter the amount of bandwidth for this interface that you want to allocate using bandwidth management. The recommendation is to set this speed to match the interface’s actual transmission speed. For example, set the WAN interface speed to 1000 kbps if your Internet connection has an upstream transmission speed of 1 Mbps. You can set this number higher than the interface’s actual transmission speed. This may stop lower priority traffic from being sent if higher priority traffic uses all of the actual bandwidth. You can also set this number lower than the interface’s actual transmission speed. If you do not enable Max Bandwidth Usage, this will cause the ZyXEL Device to not use some of the interface’s available bandwidth.Scheduler Select either Priority-Based or Fairness-Based from the drop-down menu to control the traffic flow. Select Priority-Based to give preference to bandwidth classes with higher priorities. Select Fairness-Based to treat all bandwidth classes equally.Max Bandwidth UsageSelect this check box to have the ZyXEL Device divide up all of the interface’s unallocated and/or unused bandwidth among the bandwidth classes that require bandwidth. Do not select this if you want to reserve bandwidth for traffic that does not match a bandwidth class or you want to limit the speed of this interface (see the Speed field description).Apply Click Apply to save your settings to the ZyXEL Device.Cancel Click Cancel to begin configuring this screen afresh.

Chapter 13 Bandwidth ManagementP-660HW-Dx v2 User’s Guide 193Click Advanced > Bandwidth MGMT > Rule Setup to open the following screen.Figure 110 Bandwidth Management: Rule SetupThe following table describes the labels in this screen. Table 76 Bandwidth Management: Rule SetupLABEL DESCRIPTIONDirection Select the direction of traffic to which you want to apply bandwidth management.Service Select a service for your rule or you can select User Defined to go to the screen where you can define your own.Priority Select a priority from the drop down list box. Choose High, Mid or Low.Bandwidth (kbps) Specify the maximum bandwidth allowed for the rule in kbps. The recommendation is a setting between 20 kbps and 20000 kbps for an individual rule. Add Click this button to add a rule to the following table.To LAN Interface#This is the number of an individual bandwidth management rule.Active This displays whether the rule is enabled. Select this check box to have the ZyXEL Device apply this bandwidth management rule. Enable a bandwidth management rule to give traffic that matches the rule priority over traffic that does not match the rule.Enabling a bandwidth management rule also allows you to control the maximum amounts of bandwidth that can be used by traffic that matches the rule.Rule Name This is the name of the rule.Destination Port This is the port number of the destination. 0 means any destination port.Priority This is the priority of this rule. Bandwidth (kbps) This is the maximum bandwidth allowed for the rule in kbps. Modify Click the Edit icon to go to the screen where you can edit the rule.Click the Remove icon to delete an existing rule.Apply Click Apply to save your changes to the ZyXEL Device.Cancel Click Cancel to begin configuring this screen afresh.

Chapter 13 Bandwidth ManagementP-660HW-Dx v2 User’s Guide19413.10 DiffServDiffServ is a class of service (CoS) model that marks packets so that they receive specific per-hop treatment at DiffServ-compliant network devices along the route based on the application types and traffic flow. Packets are marked with DiffServ Code Points (DSCPs) indicating the level of service desired. This allows the intermediary DiffServ-compliant network devices to handle the packets differently depending on the code points without the need to negotiate paths or remember state information for every flow. In addition, applications do not have to request a particular service or give advanced notice of where the traffic is going.13.10.1 DSCP and Per-Hop BehaviorDiffServ defines a new DS (Differentiated Services) field to replace the Type of Service (TOS) field in the IP header. The DS field contains a 2-bit unused field and a 6-bit DSCP field which can define up to 64 service levels. The following figure illustrates the DS field. DSCP is backward compatible with the three precedence bits in the ToS octet so that non-DiffServ compliant, ToS-enabled network device will not conflict with the DSCP mapping. Figure 111 DiffServ: Differentiated Service FieldThe DSCP value determines the forwarding behavior, the PHB (Per-Hop Behavior), that each packet gets across the DiffServ network. Based on the marking rule, different kinds of traffic can be marked for different priorities of forwarding. Resources can then be allocated according to the DSCP values and the configured policies.PHB consists of two types of services: EF (Expedited Forwarding) and AF (Assured Forwarding). EF has higher priority. EF guarantees services with minimal loss and delay. AF has four sub-classes, each with three levels of importance (drop precedence). A high drop precedence means low importance.13.10.2 Rule ConfigurationClick the Edit icon or select User Defined from the Service drop-down list in the Rule Setup screen to configure a bandwidth management rule. Use bandwidth rules to allocate specific amounts of bandwidth capacity (bandwidth budgets) to specific applications and/or subnets. DSCP(6-bit)Unused(2-bit)Table 77 Sub-Classes of AF ServicesDIFFSERV PRIORITY LOW DROP PRECEDENCEMEDIUM DROP PRECEDENCEHIGH DROP PRECEDENCESUB-CLASS4 AF41 AF42 AF43SUB-CLASS3 AF31 AF32 AF33SUB-CLASS2 AF21 AF22 AF23SUB-CLASS1 AF11 AF12 AF13

Chapter 13 Bandwidth ManagementP-660HW-Dx v2 User’s Guide 195Figure 112 Bandwidth Management Rule ConfigurationThe following table describes the labels in this screen. Table 78 Bandwidth Management Rule ConfigurationLABEL DESCRIPTIONRule ConfigurationActive Select this check box to have the ZyXEL Device apply this bandwidth management rule. Enable a bandwidth management rule to give traffic that matches the rule priority over traffic that does not match the rule.Enabling a bandwidth management rule also allows you to control the maximum amounts of bandwidth that can be used by traffic that matches the rule.Rule Name Use the auto-generated name or enter a descriptive name of up to 20 alphanumeric characters, including spaces.BW Budget Specify the maximum bandwidth allowed for the rule in kbps. The recommendation is a setting between 20 kbps and 20000 kbps for an individual rule.Priority Select a priority from the drop down list box. Choose High, Mid or Low. Use All Managed BandwidthSelect this option to allow a rule to borrow unused bandwidth on the interface. Bandwidth borrowing is governed by the priority of the rules. That is, a rule with the highest priority is the first to borrow bandwidth. Do not select this if you want to leave bandwidth available for other traffic types or if you want to restrict the amount of bandwidth that can be used for the traffic that matches this rule.Enable DiffServ MarkingSelect this option to enable DiffServ marking on the ZyXEL Device.

Chapter 13 Bandwidth ManagementP-660HW-Dx v2 User’s Guide196DiffServ mark Select the marking rule from the drop-down list. The first three digits are the DiffServ code point. A packet with the lowest priority mark will be dropped when the line is busy. Filter ConfigurationService This field simplifies bandwidth class configuration by allowing you to select a predefined application. When you select a predefined application, you do not configure the rest of the bandwidth filter fields (other than enabling or disabling the filter).SIP (Session Initiation Protocol) is a signaling protocol used in Internet telephony, instant messaging and other VoIP (Voice over IP) applications. Select SIP from the drop-down list box to configure this bandwidth filter for traffic that uses SIP. File Transfer Protocol (FTP) is an Internet file transfer service that operates on the Internet and over TCP/IP networks. A system running the FTP server accepts commands from a system running an FTP client. The service allows users to send commands to the server for uploading and downloading files. Select FTP from the drop-down list box to configure this bandwidth filter for FTP traffic. H.323 is a standard teleconferencing protocol suite that provides audio, data and video conferencing. It allows for real-time point-to-point and multipoint communication between client computers over a packet-based network that does not provide a guaranteed quality of service. Select H.323 from the drop-down list box to configure this bandwidth filter for traffic that uses H.323. Select User defined from the drop-down list box if you do not want to use a predefined application for the bandwidth class. When you select User defined, you need to configure at least one of the following fields (other than the Subnet Mask fields which you only enter if you also enter a corresponding destination or source IP address).Destination AddressEnter the destination IP address in dotted decimal notation.Destination Subnet NetmaskEnter the destination subnet mask. This field is N/A if you do not specify a Destination Address. Refer to the appendices for more information on IP subnetting.Destination Port Enter the port number of the destination. See Table 79 on page 197 for some common services and port numbers. A blank destination IP address means any destination IP address.Source Address Enter the source IP address in dotted decimal notation. A blank source IP address means any source IP address.Source Subnet NetmaskEnter the destination subnet mask. This field is N/A if you do not specify a Source Address. Refer to the appendices for more information on IP subnetting. A blank source port means any source port number.Source Port Enter the port number of the source. See Table 79 on page 197 for some common services and port numbers.Protocol Select the protocol (TCP or UDP) or select User defined and enter the protocol (service type) number. 0 means any protocol number.TOS (Type of Service)TOS defines the DS (Differentiated Service) field in the IP header.Enter the new TOS value of the outgoing packet (between 0 and 255). 0 is the lowest priority.TOS Mask The TOS mask is used to compare the specified (or entire) bits in the TOS IP header with the value specified in this rule.Enter the TOS Mask value between 0 (lowest priority) and 255.Back Click Back to go to the previous screen.Table 78 Bandwidth Management Rule Configuration (continued)LABEL DESCRIPTION

Chapter 13 Bandwidth ManagementP-660HW-Dx v2 User’s Guide 19713.11 Bandwidth Monitor To view the ZyXEL Device’s bandwidth usage and allotments, click Advanced > Bandwidth MGMT > Monitor. The screen appears as shown. Select an interface from the drop-down list box to view the bandwidth usage of its bandwidth rules. The gray section of the bar represents the percentage of unused bandwidth and the blue color represents the percentage of bandwidth in use. The screen refreshes every few seconds.Apply Click Apply to save your changes to the ZyXEL Device.Cancel Click Cancel to begin configuring this screen afresh.Table 79 Services and Port NumbersSERVICES PORT NUMBERECHO 7FTP (File Transfer Protocol) 21SMTP (Simple Mail Transfer Protocol) 25DNS (Domain Name System) 53Finger 79HTTP (Hyper Text Transfer protocol or WWW, Web) 80POP3 (Post Office Protocol) 110NNTP (Network News Transport Protocol) 119SNMP (Simple Network Management Protocol) 161SNMP trap 162PPTP (Point-to-Point Tunneling Protocol) 1723Table 78 Bandwidth Management Rule Configuration (continued)LABEL DESCRIPTION

Chapter 13 Bandwidth ManagementP-660HW-Dx v2 User’s Guide198Figure 113 Bandwidth Management: Monitor Table 80 Bandwidth Management MonitorLABEL DESCRIPTIONMonitor This section allows you to select which network to monitor. You may select either a LAN, WLAN, or WAN. After selecting a network to monitor, information on active services and their bandwidth usage will appear.

P-660HW-Dx v2 User’s Guide 199CHAPTER 14 Dynamic DNS SetupThis chapter discusses how to configure your ZyXEL Device to use Dynamic DNS.14.1 Dynamic DNS Overview Dynamic DNS allows you to update your current dynamic IP address with one or many dynamic DNS services so that anyone can contact you (in NetMeeting, CU-SeeMe, etc.). You can also access your FTP server or Web site on your own computer using a domain name (for instance myhost.dhs.org, where myhost is a name of your choice) that will never change instead of using an IP address that changes each time you reconnect. Your friends or relatives will always be able to call you even if they don't know your IP address.First of all, you need to have registered a dynamic DNS account with www.dyndns.org. This is for people with a dynamic IP from their ISP or DHCP server that would still like to have a domain name. The Dynamic DNS service provider will give you a password or key. 14.1.1 DYNDNS WildcardEnabling the wildcard feature for your host causes *.yourhost.dyndns.org to be aliased to the same IP address as yourhost.dyndns.org. This feature is useful if you want to be able to use, for example, www.yourhost.dyndns.org and still reach your hostname.If you have a private WAN IP address, then you cannot use Dynamic DNS.See Section 14.2 on page 199 for configuration instruction. 14.2 Configuring Dynamic DNS To change your ZyXEL Device’s DDNS, click Advanced > Dynamic DNS. The screen appears as shown.See Section 14.1 on page 199 for more information.

Chapter 14 Dynamic DNS SetupP-660HW-Dx v2 User’s Guide200Figure 114 Dynamic DNSThe following table describes the fields in this screen. Table 81 Dynamic DNSLABEL DESCRIPTIONDynamic DNS SetupActive Dynamic DNSSelect this check box to use dynamic DNS.Service Provider This is the name of your Dynamic DNS service provider.Dynamic DNS TypeSelect the type of service that you are registered for from your Dynamic DNS service provider.Host Name Type the domain name assigned to your ZyXEL Device by your Dynamic DNS provider.You can specify up to two host names in the field separated by a comma (",").User Name Type your user name.Password Type the password assigned to you.Enable Wildcard OptionSelect the check box to enable DynDNS Wildcard.Enable off line optionThis option is available when Custom DNS is selected in the DDNS Type field. Check with your Dynamic DNS service provider to have traffic redirected to a URL (that you can specify) while you are off line.IP Address Update Policy Use WAN IP AddressSelect this option to update the IP address of the host name(s) to the WAN IP address.