Cisco Linksys WRT55AG Dual-Band Wireless A+G Broadband Router User Manual WRT55AG ug Rev NC

Cisco-Linksys, LLC Dual-Band Wireless A+G Broadband Router WRT55AG ug Rev NC

User manual part 5

InternetConfiguration Type The type of Internet connection is displayed here.Status For PPPoE or PPTP, the status of the Internet connection is displayedhere. If there is no connection, you can click the Connect button to re-estab-lish it. If there is a connection, you can click the Disconnect button to end it.IP Address, Subnet Mask, and Default Gateway The Router’s IP Address,Subnet Mask, and Default Gateway Address, as seen by external users on theInternet, are displayed here.DNS The DNS (Domain Name System) IP Addresses currently used by theRouter are shown here. Multiple DNS IP settings are common. In most cases,the first available DNS entry is used.To refresh the Status screen, click the Refresh button. To get more informationabout the features, click the Help button.The Help screen, shown in Figure 7-19, offers links to all of the Router’s tech-nical support resources and the application that upgrades the Router’sfirmware. For additional information about each screen of the web-based util-ity, click the appropriate link on the lefthand side of the Help screen.55Instant Wireless®Series54Dual-Band Wireless A+G Broadband Router Firmware Version The version number of the firmware currently installed isdisplayed here.Current Time The current time, as set from the Setup tab, is displayed here.Host Name The Host Name is the name of the Router. This entry is necessaryfor some ISPs.Domain Name The Domain Name is the name of the Router's domain. Thisentry is necessary for some ISPs.LANIP Address and Subnet Mask The current IP Address and Subnet Mask ofthe Router, as seen by users on your local area network (LAN), are displayedhere. DHCP Server The status of the Router's DHCP server function is displayedhere.Wireless 5GHz, 802.11aMode The Mode setting, as set from the Setup tab, is displayed here.SSID The SSID of the 5GHz, 802.11a network is displayed here.Channel The channel for the 5GHz, 802.11a wireless network is displayedhere.Encryption Function The status of the WEP encryption is displayed here.Wireless 2.4GHz, Wireless-GMode The Mode setting, as set from the Setup tab, is displayed here.SSID The SSID of the 2.4GHz, 802.11b network is displayed here.Channel The channel for the 2.4GHz, 802.11b wireless network is displayedhere.Encryption Function The status of the WEP encryption is displayed here.HelpFigure 7-19
Dual-Band Wireless A+G Broadband Router Wireless MAC FiltersWireless access can be filtered by using the MAC addresses of the wirelessdevices transmitting within your network’s radius. Select Enable from the drop-down menu and choose if you wish to Prevent wireless access by MAC addressor Permit by MAC Address. Then, click the Edit MAC Filter List button toaccess a secondary screen, where you can enter the MAC Addresses of thedevices you wish to filter.5GHz, 802.11aAuthentication Type The default is set to Auto, which allows either OpenSystem or Shared Key authentication to be used. For Open System authentica-tion, the sender and the recipient do NOT use a WEP key for authentication.For Shared Key authentication, the sender and recipient use a WEP key forauthentication. If you want to use only Shared Key authentication, then selectShared Key. 57Figure 7-20Linksys Website Clicking this link will take you to Linksys’s website,www.linksys.com, provided you are connected to the Internet. Online User Guide in PDF Format and Adobe Website Clicking the OnlineUser Guide in PDF format link opens the Router’s User Guide. The UserGuide is in Adobe Acrobat Portable Document File (.pdf) format, so you needthe Adobe Acrobat Reader to view it. If you do not have the Acrobat Reader,click the Adobe website link to download it.The following instructions are for advanced users or users whose setup needsrequire special configuration. When you click the Advanced tab, you will beable to set up these features. There are six additional tabs available. Advanced Wireless - Allows you to customize data transmission and 802.1xsettings for your wireless network(s).Internet Filter - Enables you to set up filters that block specific internal usersfrom Internet access.Port Forwarding - Lets you set up public services on your network, such as anftp server, mail server, or web server.Routing - Enables you to configure the routing mode of the Router.DDNS - Allows you to enable the Dynamic Domain Name System (DDNS)feature, so a fixed domain name can be assigned to a dynamic Internet IPaddress.If you need to access the basic configuration tabs, click the Setup tab. The Advanced Wireless screen, shown in Figure 7-20, allows you to customizedata transmission settings. In most cases, the advanced wireless settings on thisscreen should remain at their default values.56Instant Wireless®SeriesAdvanced TabsAdvanced Wireless
Dual-Band Wireless A+G Broadband Router 59Transmission Rate The rate of data transmission should be set depending onthe speed of your wireless network. You can select from a range of transmissionspeeds (6, 9, 12, 18, 24, 36, 48, or 54Mbps), or you can select Auto to have theRouter automatically use the fastest possible data rate and enable the Auto-Fallback feature. Auto-Fallback will negotiate the best possible connectionspeed between the Router and a wireless client. The default value is Auto.Transmit Power Control The greater the transmit power used, the larger thearea a wireless network covers. To minimize the likelihood of eavesdropping byunauthorized wireless users, do not use more transmit power than necessary tocover the range needed for your wireless network. Try using the Router at dif-ferent levels of transmit power, and determine how much transmit power isneeded to reach the wireless client, such as a PC, or access point that is farthestfrom the Router. Then select the appropriate level of transmit power (Full,Half, Quarter, Eighth, or Min) from the drop-down menu. The default valueis Full.Beacon Interval The default value is 100. Enter a value between 1 and 65,535milliseconds. The Beacon Interval value indicates the frequency interval of thebeacon. A beacon is a packet broadcast by the Router to synchronize the wire-less network.DTIM Interval This value, between 1 and 16384, indicates the interval of theDelivery Traffic Indication Message (DTIM). A DTIM field is a countdownfield informing clients of the next window for listening to broadcast and mul-ticast messages. When the Router has buffered broadcast or multicast messagesfor associated clients, it sends the next DTIM with a DTIM Interval value. Itsclients hear the beacons and awaken to receive the broadcast and multicast mes-sages. The default value is 1.RTS Threshold Should you encounter inconsistent data flow, only minorreduction of the default value, 2346, is recommended. If a network packet issmaller than the preset RTS threshold size, the RTS/CTS mechanism will notbe enabled. The Router sends Request to Send (RTS) frames to a particularreceiving station and negotiates the sending of a data frame. After receiving anRTS, the wireless station responds with a Clear to Send (CTS) frame toacknowledge the right to begin transmission. The RTS Threshold value shouldremain at its default value of 2346. 58Fragmentation Threshold This value specifies the maximum size for a pack-et before data is fragmented into multiple packets. If you experience a highpacket error rate, you may slightly increase the Fragmentation Threshold.Setting the Fragmentation Threshold too low may result in poor network per-formance. Only minor reduction of the default value is recommended. In mostcases, it should remain at its default value of 2346.2.4GHz, 54g/Wireless-GAuthentication Type The default is set to Auto, which allows either OpenSystem or Shared Key authentication to be used. For Open System authentica-tion, the sender and the recipient do NOT use a WEP key for authentication.For Shared Key authentication, the sender and recipient use a WEP key forauthentication. If you want to use only Shared Key authentication, then selectShared Key. Transmission Rate The rate of data transmission should be set depending onthe speed of your wireless network. You can select from a range of transmissionspeeds (6, 9, 12, 18, 24, 36, 48, or 54Mbps), or you can select Auto to have theRouter automatically use the fastest possible data rate and enable the Auto-Fallback feature. Auto-Fallback will negotiate the best possible connectionspeed between the Router and a wireless client. The default value is Auto.Beacon Interval The Beacon Interval value indicates the frequency interval ofthe beacon. Enter a value between 20 and 1000. A beacon is a packet broadcastby the Router to synchronize the wireless network. The default value is 100.DTIM Interval This value, between 1 and 16384, indicates the interval of theDelivery Traffic Indication Message (DTIM). A DTIM field is a countdownfield informing clients of the next window for listening to broadcast and mul-ticast messages. When the Router has buffered broadcast or multicast messagesfor associated clients, it sends the next DTIM with a DTIM Interval value. Itsclients hear the beacons and awaken to receive the broadcast and multicast mes-sages. The default value is 1.RTS Threshold Should you encounter inconsistent data flow, only minorreduction of the default value, 2346, is recommended. If a network packet issmaller than the preset RTS threshold size, the RTS/CTS mechanism will notbe enabled. The Router sends Request to Send (RTS) frames to a particularreceiving station and negotiates the sending of a data frame. After receiving anRTS, the wireless station responds with a Clear to Send (CTS) frame toacknowledge the right to begin transmission. The RTS Threshold value shouldremain at its default value of 2346. Instant Wireless®Series
Internet Access Policy Multiple Filters can be saved as Internet AccessPolicies. When you wish to edit one, select the number of the Policy from thedrop-down menu. The tab will change to reflect the settings of this Policy. Ifyou wish to delete this Policy, click the Delete button.To see a summary of all Policies, click the Summary button.The summaries are list-ed on this screen,shown in Figure 7-22,with their name andsettings. To delete anysummary from thisscreen, check theempty box beneathDelete and then clickthe Delete button. Toreturn to the Filters tab,click the Close button.Enter Policy Name Policies are created from the fields presented here. Tocreate a policy:1. Enter a Policy Name in the field provided.2. Click the Edit Listof PCs button. Thiswill open the List ofPCs screen, shownin Figure 7-23.From this screen,you can enter the IPaddress or MACaddress of any PCto which this policywill apply. You caneven enter ranges ofPCs by IP address.Click the Applybutton to save your settings, the Cancel button to undo any changes, and theClose button to return to the Filters tab.61Dual-Band Wireless A+G Broadband Router Fragmentation Threshold This value specifies the maximum size for a pack-et before data is fragmented into multiple packets. If you experience a highpacket error rate, you may slightly increase the Fragmentation Threshold.Setting the Fragmentation Threshold too low may result in poor network per-formance. Only minor reduction of this value is recommended. In most cases,it should remain at its default value of 2346. To apply any of the settings you change on this page, click the Apply button.To cancel any changes you’ve entered on this page, click the Cancel button. Toget more information about the features, click the Help button.The Internet Filter tab, shown in Figure 7-21, allows you to block or allow spe-cific kinds of Internet usage. You can set up Internet access policies for specif-ic PCs and set up filters by using network port numbers.60Instant Wireless®SeriesInternet FilterFigure 7-21Figure 7-22Figure 7-23
Dual-Band Wireless A+G Broadband Router 63The Port Forwarding screen, shown in Figure 7-25, sets up public services onyour network, such as web servers, ftp servers, e-mail servers, or other spe-cialized Internet applications. (Specialized Internet applications are any appli-cations that use Internet access to perform functions such as videoconferencingor online gaming. Some Internet applications may not require any forwarding.)Customized Applications In the field provided, enter the name you wish togive each application.External Port For each application, enter the number of the External Ports(the port numbers seen by users on the Internet) in the appropriate fields. (Tofind out the port range, check your application’s documentation.) If there isonly one External Port, enter its number in both External Port fields.Port ForwardingFigure 7-25Note: Any PC whose port is being forwarded should have its DHCPclient function disabled and a new static IP address assigned to itbecause its IP address may change when using the DHCP function.Instant Wireless®Series623. Select if you wish to Disable or Enable Internet access for those PCs youlisted on the List of PCs screen by clicking the radio button beside eitheroption.4. You can filteraccess to variousservices accessedover the Internet,such as FTP orTelnet, by selectinga service from thepull-down menusnext to Services. Ifa service isn’t listed,you can click theAdd Service buttonto open the Servicescreen, shown in Figure 7-24, and add a service to the list. You will need toenter a Service name, as well as the Protocol and Port Range used by theservice.5. By selecting the appropriate setting next to Days and Time, choose whenInternet access will be filtered.6. Lastly, click the Apply button to save and activate this policy.Internet Access can also be filtered by URL Address, the address entered toaccess Internet sites, by entering the address in one of the Website Blockingby URL Address fields. If you do not know the URL Address, filtering can bedone by Keyword by entering a keyword in one of the Website Blocking byKeyword fields.To apply any of the settings you change on this page, click the Apply button. Tocancel any changes you’ve entered on this page, click the Cancel button. To getmore information about the features, click the Help button.Figure 7-24
Dual-Band Wireless A+G Broadband Router 65Protocol TCP Click this checkbox if you want to forward the data transmis-sions that use the TCP protocol.Protocol UDP Click this checkbox if you want to forward the data transmis-sions that use the UDP protocol.IP Address For each application, enter the IP Address of the PC running thespecific application.Enable Click the Enable checkbox to enable port forwarding for the relevantapplication.The following table shows the typical port forwarding settings for commonInternet applications.To apply any of the settings you change on this page, click the Apply button. Tocancel any changes you’ve entered on this page, click the Cancel button. To getmore information about the features, click the Help button.64Instant Wireless®SeriesFTPApplications External Port TCP Protocol UDP Protocol21 √Telnet 23 √SMTP 25 √DNS 53 √TFTP 69 √Finger 79 √HTTP 80 √POP3 110 √NNTP 119 √SNMP 161 √Port Triggering Port Triggering is used for special Internet applications whoseoutgoing ports differ from the incoming ports. For this feature, the Router willwatch outgoing data for specific port numbers. The Router will remember theIP address of the computer that sends a transmission requesting data, so thatwhen the requested data returns through the Router, the data is pulled back tothe proper computer by way of IP address and port mapping rules. Click thePort Triggering button to set up triggered ports, and follow these instructions:1. Enter theApplicationName of thetrigger (seeFigure 7-26).2. Enter the Outgoing Port Range used by the application. Check with theInternet application for the port number(s) needed.3. Enter the Incoming Port Range used by the application. Check with theInternet application for the port number(s) needed.4. Click the Apply button to save your changes. Click the Cancel button tocancel your unsaved changes. Click the Close button to return to the PortForwarding screen.To save your changes on this page, click the Apply button. To cancel anyunsaved changes on this page, click the Cancel button. To get more informa-tion about the features, click the Help button.Figure 7-26
67Instant Wireless®Series66Dual-Band Wireless A+G Broadband Router 4. To set up a static route between the Router and another network, select anumber from the Static Routing drop-down list. (A static route is a pre-determined pathway that network information must travel to reach a spe-cific host or network.)5. Enter the following data:• Enter Route Name - Enter a name for the Route here, using a maxi-mum of 25 alphanumeric characters.• Destination LAN IP - The Destination LAN IP is the address of theremote network or host to which you want to assign a static route.• Subnet Mask - The Subnet Mask determines which portion of aDestination LAN IP address is the network portion, and which portionis the host portion. • Gateway - This is the IP address of the gateway device that allows forcontact between the Router and the remote network or host.•Interface - This interface tells you whether the Destination IP Addressis on the LAN & Wireless (internal wired and wireless networks), theWA N (Internet), or Loopback (a dummy network in which one PCacts like a network-necessary for certain software programs). 6. To cancel your changes, click the Cancel button. To save your changes,click the Apply button. To get more information about the features, clickthe Help button.To delete a static route entry:1. From the Static Routing drop-down list, select the entry number of the stat-ic route.2. Click the Delete This Entry button.3. To cancel a deletion, click the Cancel button. To save a deletion, click theApply button. To get more information about the features, click the Helpbutton.On the Routing screen, shown in Figure 7-27, you can set the routing mode ofthe Router. Gateway mode is recommended for most users. To set up routing:1. Choose the correct working mode. Select Gateway if the Router is hostingyour network’s connection to the Internet (recommended for most users).Select Router if the Router exists on a network with other routers.2. If you selected the Gateway mode, click the Apply button. If you selectedthe Router mode, proceed to step 3.3. For Dynamic Routing, the default is Disable. The Dynamic Routing featureenables the Router to automatically adjust to physical changes in the net-work’s layout and exchange routing tables with the other router(s). TheRouter determines the network packets’ route based on the fewest numberof hops between the source and the destination. Select Enable to enable theDynamic Routing feature for data transmissions.RoutingFigure 7-27Note: The Routing screen and available features will vary dependingon which mode you select.Note: If you have more than one router on your network, you shouldselect Router for the working mode.
69Instant Wireless®Series68Dual-Band Wireless A+G Broadband Router Show Routing Table Click the Show Routing Table button to view all of thevalid dynamic and static route entries in use (see Figure 7-28). The DestinationLAN IP address, Subnet Mask, Gateway, and Interface information are dis-played for each entry. Click the Refresh button to display the most up-to-datedata.The Router offers a Dynamic Domain Name System (DDNS) feature. DDNSlets you assign a fixed host and domain name to a dynamic Internet IP address.It is useful when you are hosting your own website, FTP server, or other serv-er behind the Router. Before you can use this feature, you need to sign up forDDNS service at www.dyndns.org, or www.TZO.com, DDNS service providers.Figure 7-28DDNS Service To enable DDNS Service, select Enable and follow theseinstructions:1. Sign up for a DDNS service and write down your User Name, Password,and Host Name information.2. On the DDNS screen, select Enable. 3. Complete the User Name, Password, and Host Name fields.4. To save your new settings, click the Apply button. To cancel your changes,click the Cancel button.Internet IP Address The Router’s current Internet IP Address is displayedhere.Status The status of the DDNS service connection is displayed here.To save your changes on this page, click the Apply button. To cancel anyunsaved changes on this page, click the Cancel button. To get more informationabout the features, click the Help button.DDNSFigure 6-27
For Windows 2000:A. Click Start, Settings, and Control Panel. Double-click Network andDial-Up Connections.B. Right-click the Local Area Connection that is associated with the Ethernetadapter you are using, and select the Properties option.C. In the Components checked are used by this connection box, highlightInternet Protocol (TCP/IP), and click the Properties button. Select Usethe following IP address option.D. Enter a unique IP address that is not used by any other computer on thenetwork connected to the Router. You can only use an IP address in theranges 192.168.1.2 to 192.168.1.99 and 192.168.1.151 to 192.168.1.254. E. Enter the Subnet Mask, 255.255.255.0.F. Enter the Default Gateway, 192.168.1.1 (Router’s default IP address).G. Toward the bottom of the window, select Use the following DNS serveraddresses, and enter the Preferred DNS server and Alternative DNSserver (provided by your ISP). Contact your ISP or go on its website to findthe information.H. Click the OK button in the Internet Protocol (TCP/IP) Properties window,and click the OK button in the Local Area Connection Properties window.I. Restart the computer if asked.For Windows NT 4.0:A. Click Start, Settings, and Control Panel. Double-click the Network icon.B. Click the Protocol tab, and double-click TCP/IP Protocol.C. When the window appears, make sure you have selected the correctAdapter for your Ethernet adapter.D. Select Specify an IP address, and enter a unique IP address that is notused by any other computer on the network connected to the Router. Youcan only use an IP address in the ranges 192.168.1.2 to 192.168.1.99 and192.168.1.151 to 192.168.1.254.E. Enter the Subnet Mask, 255.255.255.0.F. Enter the Default Gateway, 192.168.1.1 (Router’s default IP address).G. Click the DNS tab, and enter the Host and Domain names (e.g., John forHost and home for Domain). Under DNS Service Search Order, click theAdd button. Enter the DNS IP address in the DNS Server field, and clickthe Add button. Repeat this action for all DNS IP addresses given by yourISP.H. Click the OK button in the TCP/IP Protocol Properties window, and clickthe Close button in the Network window.I. Restart the computer if asked.71Instant Wireless®Series70Dual-Band Wireless A+G Broadband Router Appendix A: TroubleshootingThis appendix consists of two parts: “Common Problems and Solutions” and“Frequently Asked Questions.” Provided are possible solutions to problems thatmay occur during the installation and operation of the Router. Read the descrip-tions below to help solve your problems. If you can’t find an answer here, checkthe Linksys website at www.linksys.com.1. I need to set a static IP address on a PC.The Router, by default, assigns an IP address range of 192.168.1.100 to192.168.1.150 using the DHCP server on the Router. To set a static IP address,you can only use the ranges 192.168.1.2 to 192.168.1.99 and 192.168.1.151 to192.168.1.254. Each PC or network device that uses TCP/IP must have aunique address to identify itself in a network. If the IP address is not unique toa network, Windows will generate an IP conflict error message. You can assigna static IP address to a PC by performing the following steps:For Windows 98 and Me:A. Click Start, Settings, and Control Panel. Double-click Network.B. In The following network components are installed box, select the TCP/IP->associated with your Ethernet adapter. If you only have one Ethernet adapterinstalled, you will only see one TCP/IP line with no association to an Ethernetadapter. Highlight it and click the Properties button.C. In the TCP/IP properties window, select the IP address tab, and selectSpecify an IP address. Enter a unique IP address that is not used by anyother computer on the network connected to the Router. You can only usean IP address in the ranges 192.168.1.2 to 192.168.1.99 and 192.168.1.151to 192.168.1.254. Make sure that each IP address is unique for each PC ornetwork device.D. Click the Gateway tab, and in the New Gateway prompt, enter 192.168.1.1,which is the default IP address of the Router. Click the Add button to acceptthe entry.E. Click the DNS tab, and make sure the DNS Enabled option is selected.Enter the Host and Domain names (e.g., John for Host and home forDomain). Enter the DNS entry provided by your ISP. If your ISP has notprovided the DNS IP address, contact your ISP to get that information or goto its website for the information.F. Click the OK button in the TCP/IP properties window, and click Close orthe OK button for the Network window.G. Restart the computer when asked.Common Problems and Solutions
73Instant Wireless®Series72Dual-Band Wireless A+G Broadband Router B. Open a command prompt.• For Windows 98 and Me, please click Start and Run. In the Open field,type in command. Press the Enter key or click the OK button.• For Windows NT, 2000, and XP, please click Start and Run. In theOpen field, type cmd. Press the Enter key or click the OK button.C. In the command prompt, type ping 192.168.1.1 and press the Enter key. • If you get a reply, the computer is communicating with the Router.• If you do NOT get a reply, please check the cable, and make sure Obtainan IP address automatically is selected in the TCP/IP settings for yourEthernet adapter. D. In the command prompt, type ping followed by your Internet or WAN IPaddress and press the Enter key. The Internet or WAN IP Address can befound on the Status screen of the Router’s web-based utility. For example,if your Internet or WAN IP address is 1.2.3.4, you would enter ping 1.2.3.4and press the Enter key.• If you get a reply, the computer is connected to the Router.• If you do NOT get a reply, try the ping command from a different com-puter to verify that your original computer is not the cause of the problem.E. In the command prompt, type ping www.yahoo.com and press the Enterkey. • If you get a reply, the computer is connected to the Internet. If you can-not open a webpage, try the ping command from a different computer toverify that your original computer is not the cause of the problem.• If you do NOT get a reply, there may be a problem with the connection.Try the ping command from a different computer to verify that your orig-inal computer is not the cause of the problem.3. I am not getting an IP address on the Internet with my Internet connection.A. Refer to “Problem #2, I want to test my Internet connection” to verify thatyou have connectivity.B. If you need to register the MAC address of your Ethernet adapter with yourISP, please see “Appendix D: Finding the MAC address and IP Address forYour Ethernet Adapter.” If you need to clone the MAC address of yourEthernet adapter onto the Router, see the MAC Address Clone section of“Chapter 7: The Router’s Web-based Utility” for details.C. Make sure you are using the right Internet connection settings. Contact yourISP to see if your Internet connection type is DHCP, Static IP Address, orPPPoE (commonly used by DSL consumers). Please refer to the Setup sec-tion of “Chapter 7: The Router’s Web-based Utility” for details on Internetconnection settings.For Windows XP:The following instructions assume you are running Windows XP with thedefault interface. If you are using the Classic interface (where the icons andmenus look like previous Windows versions), please follow the instructions forWindows 2000.A. Click Start and Control Panel. B. Click the Network and Internet Connections icon and then the NetworkConnections icon.C. Right-click the Local Area Connection that is associated with the Ethernetadapter you are using, and select the Properties option.D. In the This connection uses the following items box, highlight InternetProtocol (TCP/IP). Click the Properties button.E. Enter a unique IP address that is not used by any other computer on the net-work connected to the Router. You can only use an IP address in the ranges192.168.1.2 to 192.168.1.99 and 192.168.1.151 to 192.168.1.254. F. Enter the Subnet Mask, 255.255.255.0.G. Enter the Default Gateway, 192.168.1.1 (Router’s default IP address).H. Toward the bottom of the window, select Use the following DNS serveraddresses, and enter the Preferred DNS server and Alternative DNSserver (provided by your ISP). Contact your ISP or go on its website to findthe information.I. Click the OK button in the Internet Protocol (TCP/IP) Properties window.Click the OK button in the Local Area Connection Properties window.2. I want to test my Internet connection.A. Check your TCP/IP settings. For Windows 98, Me, 2000, and XP:Refer to “Chapter 4: Configure the PCs” for details. Make sure Obtain IPaddress automatically is selected in the settings.For Windows NT 4.0:• Click Start, Settings, and Control Panel. Double-click the Networkicon.• Click the Protocol tab, and double-click on TCP/IP Protocol.• When the window appears, make sure you have selected the correctAdapter for your Ethernet adapter and set it for Obtain an IP addressfrom a DHCP server.• Click the OK button in the TCP/IP Protocol Properties window, andclick the Close button in the Network window.• Restart the computer if asked.
of the web interface. If you assigned a static IP address to any computer or net-work device on the network, you need to change its IP address accordingly to192.168.2.Y (Y being any number from 1 to 254). Note that each IP addressmust be unique within the network.Your VPN may require port 500/UDP packets to be passed to the computer thatis connecting to the IPSec server. Refer to “Problem #7, I need to set up onlinegame hosting or use other Internet applications” for details. Check the Linksys website for more information at www.linksys.com.6. I need to set up a server behind my Router.To use a server like a web, ftp, or mail server, you need to know the respectiveport numbers they are using. You can get more information by viewing the doc-umentation provided with the server you installed. Follow these steps to set upport forwarding through the Router’s web-based utility. We will be setting upweb, ftp, and mail servers.A. Access the Router’s web-based utility by going to http://192.168.1.1 or theIP address of the Router. Go to the Advanced => Port Forwarding tab. B. Enter any name you want to use for the Customized Application.C. Enter the External Port range of the service you are using. For example,if you have a web server, you would enter the range 80 to 80. D. Check the protocol you will be using, TCP and/or UDP. E. Enter the IP address of the PC or network device that you want the portserver to go to. For example, if the web server’s Ethernet adapter IP addressis 192.168.1.100, you would enter 100 in the field provided. Check“Appendix D: Finding the MAC Address and IP Address for Your EthernetAdapter” for details on getting an IP address.F. Check the Enable option for the port services you want to use. Consider theexample below:Customized External Port TCP UDP IP Address EnableApplicationWeb server 80 to 80 X X 192.168.1.100 XFTP server 21 to 21 X 192.168.1.101 XSMTP (outgoing) 25 to 25 X X 192.168.1.102 XPOP3 (incoming) 110 to 110 X X 192.168.1.102 XWhen you have completed the configuration, click the Apply button.75Instant Wireless®Series74Dual-Band Wireless A+G Broadband Router D. Make sure you have the right cable. Check to see if the Internet column hasa solidly lit Link/Act LED. E. Make sure the cable connecting from your cable or DSL modem is con-nected to the Router’s Internet port. Verify that the Status page of theRouter’s web-based utility shows a valid IP address from your ISP.F. Turn off the computer, Router, and cable/DSL modem. Wait 30 seconds,and then turn on the Router, cable/DSL modem, and computer. Check theStatus tab of the Router’s web-based utility to see if you get an IP address. 4. I am not able to access the Setup page of the Router’s web-based utility.A. Refer to “Problem #2, I want to test my Internet connection” to verify thatyour computer is properly connected to the Router.B. Refer to “Appendix D: Finding the MAC Address and IP address for YourEthernet Adapter” to verify that your computer has an IP Address, SubnetMask, Gateway, and DNS.C. Set a static IP address on your system; refer to “Problem #1: I need to set astatic IP address.”D. Refer to “Problem #10: I need to remove the proxy settings or the dial-uppop-up window (for PPPoE users).”5. I can’t get my Virtual Private Network (VPN) working through the Router.Access the Router’s web interface by going to http://192.168.1.1 or the IPaddress of the Router, go to the System tab. Make sure you have IPsec pass-through, L2TP, and PPTP pass-through enabled.VPNs that use IPSec with the ESP (Encapsulation Security Payload known asprotocol 50) authentication will work fine. At least one IPSec session will workthrough the Router; however, simultaneous IPSec sessions may be possible,depending on the specifics of your VPNs.VPNs that use IPSec and AH (Authentication Header known as protocol 51)are incompatible with the Router. AH has limitations due to occasional incom-patibility with the NAT standard. Change the IP address for the Router to another subnet to avoid a conflictbetween the VPN IP address and your local IP address. For example, if yourVPN server assigns an IP address 192.168.1.X (X is a number from 1 to 254)and your local LAN IP address is 192.168.1.X (X is the same number used inthe VPN IP address), the Router will have difficulties routing information tothe right location. If you change the Router’s IP address to 192.168.2.1, thatshould solve the problem. Change the Router’s IP address through the Setup tab
settings. If the port number that the data enters from does not have port for-warding, then the Router will send the data to whichever PC or network deviceyou set for DMZ hosting.) Follow these steps to set DMZ hosting:A. Access the Router’s web-based utility by going to http://192.168.1.1 or theIP address of the Router. Go to the Advanced => Port Forwarding tab.B. Disable or remove the entries you have entered for forwarding. Keep thisinformation in case you want to use it at a later time.C. Click the Security tab and select DMZ Host.D. Enter the Ethernet adapter’s IP address of the computer you want exposedto the Internet. This will bypass the NAT firewall for that computer. Pleaserefer to “Appendix D: Finding the MAC Address and IP Address for YourEthernet Adapter” for details on getting an IP address. Once completed with the configuration, click the Apply button.9. I forgot my password, or the password prompt always appears when I am sav-ing settings to the Router.Reset the Router to factory default by pressing the Reset button for 10 secondsand then releasing it. If you are still getting prompted for a password when sav-ing settings, then perform the following steps:A. Access the Router’s web-based utility by going to http://192.168.1.1 or theIP address of the Router. Enter the default password admin, and click theSecurity tab. B. Enter a different password in the Router Password field, and enter thesame password in the second field to confirm the password.C. Click the Apply button.10. I am a PPPoE user, and I need to remove the proxy settings or the dial-up pop-up window.If you have proxy settings, you need to disable these on your computer.Because the Router is the gateway for the Internet connection, the computerdoes not need any proxy settings to gain access. Please follow these directionsto verify that you do not have any proxy settings and that the browser you useis set to connect directly to the LAN.For Microsoft Internet Explorer 5.0 or higher:A. Click Start, Settings, and Control Panel. Double-click Internet Options. B. Click the Connections tab.C. Click the LAN settings button and remove anything that is checked.D. Click the OK button to go back to the previous screen.77Instant Wireless®Series7. I need to set up online game hosting or use other Internet applications.If you want to play online games or use Internet applications, most will workwithout doing any port forwarding or DMZ hosting. There may be cases whenyou want to host an online game or Internet application. This would require youto set up the Router to deliver incoming packets or data to a specific comput-er. This also applies to the Internet applications you are using. The best way toget the information on what port services to use is to go to the website of theonline game or application you want to use. Follow these steps to set up onlinegame hosting or use a certain Internet application:A. Access the Router’s web interface by going to http://192.168.1.1 or the IPaddress of the Router. Go to the Advanced => Port Forwarding tab.B. Enter any name you want to use for the Customized Application.C. Enter the External Port range of the service you are using. For example,if you want to host Unreal Tournament (UT), you would enter the range7777 to 27900.D. Check the protocol you will be using, TCP and/or UDP. E. Enter the IP address of the PC or network device that you want the portserver to go to. For example, if the web server’s Ethernet adapter IP addressis 192.168.1.100, you would enter 100 in the field provided. Check“Appendix D: Finding the MAC Address and IP Address for Your EthernetAdapter” for details on getting an IP address.F. Check the Enable option for the port services you want to use. Consider theexample below:Customized External Port TCP UDP IP Address EnableApplicationUT 7777 to 27900 X X 192.168.1.100 X Halflife 27015 to 27015 X X 192.168.1.105 XPC Anywhere 5631 to 5631 X 192.168.1.102 XVPN IPSEC 500 to 500 X 192.168.1.100 XWhen you have completed the configuration, click the Apply button.8. I can’t get the Internet game, server, or application to work.If you are having difficulties getting any Internet game, server, or applicationto function properly, consider exposing one PC to the Internet usingDeMilitarized Zone (DMZ) hosting. This option is available when an applica-tion requires too many ports or when you are not sure which port services touse. Make sure you disable all the forwarding entries if you want to success-fully use DMZ hosting, since forwarding has priority over DMZ hosting. (Inother words, data that enters the Router will be checked first by the forwarding 76Dual-Band Wireless A+G Broadband Router
C. Perform the upgrade using the Upgrade Utility, TFTP program or Router’sweb-based utility through its Help tab.14. My DSL service’s PPPoE is always disconnecting.PPPoE is not actually a dedicated or always-on connection. The DSL ISP candisconnect the service after a period of inactivity, just like a normal phone dial-up connection to the Internet. There is a setup option to “keep alive” the con-nection. This may not always work, so you may need to re-establish connec-tion periodically.A. To connect to the Router, go to the web browser, and enterhttp://192.168.1.1 or the IP address of the Router.B. Enter the password, if asked. (The default password is admin.)C. On the Setup screen, select the option Keep Alive, and set the RedialPeriod option at 30 (seconds).D. Click the Apply button.E. Click the Status tab, and click the Connect button.F. You may see the login status display as Connecting. Press the F5 key torefresh the screen, until you see the login status display as Connected.G. Click the Apply button to continue.If the connection is lost again, follow steps E to G to re-establish connection.15. I can’t access my e-mail, web, or VPN, or I am getting corrupted data from theInternet.The Maximum Transmission Unit (MTU) setting may need to be adjusted. Bydefault, the MTU is set at 1400. For most DSL users, it is strongly recom-mended to use MTU 1492. If you are having some difficulties, perform the fol-lowing steps:A. To connect to the Router, go to the web browser, and enterhttp://192.168.1.1 or the IP address of the Router.B. Enter the password, if asked. (The default password is admin.)C. Click the System tab.D. Look for the MTU option, and select Manual. In the Size field, enter 1492. E. Click the Apply button to continue.79Instant Wireless®SeriesE. Click the option Never dial a connection. This will remove any dial-uppop-ups for PPPoE users.For Netscape 4.7 or higher:A. Start Netscape Navigator, and click Edit, Preferences, Advanced, andProxies. B. Make sure you have Direct connection to the Internet selected on thisscreen.C. Close all the windows to finish.11. To start over, I need to set the Router to factory default.Hold the Reset button for 10 seconds and then release it. This will return thepassword, forwarding, and other settings on the Router to the factory defaultsettings. In other words, the Router will revert to its original factory configu-ration.12. I need to upgrade the firmware.In order to upgrade the firmware with the latest features, you need to go to theLinksys website and download the latest firmware at www.linksys.com. Followthese steps:A. Go to the Linksys website at http://www.linksys.com and download thelatest firmware.B. To upgrade the firmware, follow the steps in the Help section found in“Chapter 7: The Router’s Web-based Utility.”13. The firmware upgrade failed, and/or the Diag LED is flashing.The upgrade could have failed for a number of reasons. Follow these steps toupgrade the firmware and/or make the Diag LED stop flashing:A. If the firmware upgrade failed, use the TFTP program (it was downloadedalong with the firmware). Open the pdf that was downloaded along with thefirmware and TFTP program, and follow the pdf’s instructions.B. Set a static IP address on the PC; refer to “Problem #1, I need to set a stat-ic IP address.” Use the following IP address settings for the computer youare using:IP Address: 192.168.1.50Subnet Mask: 255.255.255.0Gateway: 192.168.1.178Dual-Band Wireless A+G Broadband Router
What is the maximum number of IP addresses that the Router will support? The Router will support up to 253 IP addresses.Is IPSec Pass-Through supported by the Router?Yes, it is a built-in feature that the Router automatically enables.Where is the Router installed on the network? In a typical environment, the Router is installed between the cable/DSL modemand the LAN. Plug the Router into the cable/DSL modem’s Ethernet port.Does the Router support IPX or AppleTalk? No. TCP/IP is the only protocol standard for the Internet and has become theglobal standard for communications. IPX, a NetWare communications protocolused only to route messages from one node to another, and AppleTalk, a com-munications protocol used on Apple and Macintosh networks, can be used forLAN to LAN connections, but those protocols cannot connect from the Internetto a LAN.Does the Internet connection of the Router support 100Mbps Ethernet? The Router’s current hardware design supports up to 100Mbps Ethernet on itsInternet port; however, the Internet connection speed will vary depending onthe speed of your broadband connection. The Router also supports 100Mbpsover the auto-sensing Fast Ethernet 10/100 switch on the LAN side of theRouter. What is Network Address Translation and what is it used for?Network Address Translation (NAT) translates multiple IP addresses on the pri-vate LAN to one public address that is sent out to the Internet. This adds a levelof security since the address of a PC connected to the private LAN is nevertransmitted on the Internet. Furthermore, NAT allows the Router to be usedwith low cost Internet accounts, such as DSL or cable modems, when only oneTCP/IP address is provided by the ISP. The user may have many privateaddresses behind this single address provided by the ISP.Does the Router support any operating system other than Windows 95, Windows98, Windows Millennium, Windows 2000, Windows NT, or Windows XP? Yes, but Linksys does not, at this time, provide technical support for setup, con-figuration or troubleshooting of any non-Windows operating systems.81Instant Wireless®SeriesIf your difficulties continue, change the Size to different values. Try this list ofvalues, one value at a time, in this order, until your problem is solved:146214001362130016. The Diag LED stays lit continuously.• The Diag LED lights up when the device is first powered up. Meantime,the system will boot up itself and check for proper operation. After fin-ishing the checking procedure, the LED turns off to show that the systemis working fine. If the LED remains lit after this time, the device is notworking properly. Try to flash the firmware by assigning a static IPaddress to the computer, and then upgrade the firmware. Try using thefollowing settings, IP Address: 192.168.1.50 and Subnet Mask:255.255.255.0.17. When I enter a URL or IP address, I get a time-out error or am prompted to retry.• Check if other PCs work. If they do, ensure that your workstation’s IP set-tings are correct (IP Address, Subnet Mask, Default Gateway, and DNS).Restart the computer that is having a problem.• If the PCs are configured correctly, but still not working, check theRouter. Ensure that it is connected and powered on. Connect to it andcheck its settings. (If you cannot connect to it, check the LAN and powerconnections.)• If the Router is configured correctly, check your Internet connection(DSL/cable modem, etc.) to see if it is working correctly. You can removethe Router to verify a direct connection.• Manually configure the TCP/IP settings with a DNS address provided byyour ISP.• Make sure that your browser is set to connect directly and that any dial-up is disabled. For Internet Explorer, click Tools, Internet Options, andthen the Connection tab. Make sure that Internet Explorer is set to Neverdial a connection. For Netscape Navigator, click Edit, Preferences,Advanced, and Proxy. Make sure that Netscape Navigator is set toDirect connection to the Internet.18. The Full/Col LED keeps flickering continuously.• Check the Category 5 Ethernet network cable and its RJ-45 connectors.• There may be interference with other network devices. Try removingother PCs or network devices to see if the problem persists. Eliminateeach network device one at a time to determine the cause.80Dual-Band Wireless A+G Broadband Router Frequently Asked Questions
83Instant Wireless®Series82Dual-Band Wireless A+G Broadband Router Properties tab.) Make sure that your proxy setting is disabled in the browser.Check our website at www.linksys.com for more information.If all else fails in the installation, what can I do?Reset the Router by holding down the reset button until the Diag LED fullyturns on and off. Reset your cable or DSL modem by powering the unit off andthen on. Obtain and flash the latest firmware release that is readily availableon the Linksys website, www.linksys.com.How will I be notified of new Router firmware upgrades?All Linksys firmware upgrades are posted on the Linksys website atwww.linksys.com, where they can be downloaded for free. To upgrade theRouter’s firmware, use the Help tab of the Router’s web-based utility. If theRouter’s Internet connection is working well, there is no need to download anewer firmware version, unless that version contains new features that youwould like to use. Downloading a more current version of Router firmwarewill not enhance the quality or speed of your Internet connection, and may dis-rupt your current connection stability.Will the Router function in a Macintosh environment? Yes, but the Router’s setup pages are accessible only through Internet Explorer4.0 or Netscape Navigator 4.0 or higher for Macintosh.I am not able to get the web configuration screen for the Router. What can I do?You may have to remove the proxy settings on your Internet browser, e.g.,Netscape Navigator or Internet Explorer. Or remove the dial-up settings onyour browser. Check with your browser documentation, and make sure thatsure that your browser is set to connect directly and that any dial-up is disabled.For Internet Explorer, click Tools, Internet Options, and then the Connectiontab. Make sure that Internet Explorer is set to Never dial a connection. ForNetscape Navigator, click Edit, Preferences, Advanced, and Proxy. Makesure that Netscape Navigator is set to Direct connection to the Internet.What is DMZ Hosting?Demilitarized Zone (DMZ) allows one IP address (computer) to be exposed tothe Internet. Some applications require multiple TCP/IP ports to be open. It isrecommended that you set your computer with a static IP if you want to useDMZ Hosting. To get the LAN IP address, see “Appendix D: Finding the MACAddress and IP Address for Your Ethernet Adapter.”Does the Router support ICQ send file?Yes, with the following fix: click ICQ menu -> preference -> connectionstab->, and check I am behind a firewall or proxy. Then set the firewall time-out to 80 seconds in the firewall setting. The Internet user can then send a fileto a user behind the Router.I set up an Unreal Tournament Server, but others on the LAN cannot join. What doI need to do? If you have a dedicated Unreal Tournament server running, you need to createa static IP for each of the LAN computers and forward ports 7777, 7778, 7779,7780, 7781, and 27900 to the IP address of the server. You can also use a portforwarding range of 7777 ~ 27900. If you want to use the UT Server Admin,forward another port. (Port 8080 usually works well but is used for remoteadmin. You may have to disable this.) Then in the [UWeb.WebServer] sectionof the server.ini file, set the ListenPort to 8080 (to match the mapped portabove) and ServerName to the IP assigned to the Router from your ISP.Can multiple gamers on the LAN get on one game server and play simultaneouslywith just one public IP address?It depends on which network game or what kind of game server you are using.For example, Unreal Tournament supports multi-login with one public IP.How do I get Half-Life: Team Fortressto work with the Router?The default client port for Half-Life is 27005. The computers on your LANneed to have “+clientport 2700x” added to the HL shortcut command line; thex would be 6, 7, 8, and on up. This lets multiple computers connect to the sameserver. One problem: Version 1.0.1.6 won’t let multiple computers with thesame CD key connect at the same time, even if on the same LAN (not a prob-lem with 1.0.1.3). As far as hosting games, the HL server does not need to bein the DMZ. Just forward port 27015 to the local IP address of the server com-puter. How can I block corrupted FTP downloads? If you are experiencing corrupted files when you download a file with your FTPclient, try using another FTP program.The web page hangs; downloads are corrupt, or nothing but junk characters arebeing displayed on the screen. What do I need to do?Force your Ethernet adapter to 10Mbps or half duplex mode, and turn off the“Auto-negotiate” feature of your Ethernet adapter as a temporary measure.(Please look at the Network Control Panel in your Ethernet adapter’s Advanced
85Instant Wireless®Series84Dual-Band Wireless A+G Broadband Router What is the IEEE 802.11a standard?It is one of the IEEE standards for wireless networks. The 802.11a standardallows wireless networking hardware from different manufacturers to commu-nicate, provided that the hardware complies with the 802.11a standard. The802.11a standard states a maximum data transfer rate of 54Mbps and an oper-ating frequency of 5GHz.What is the IEEE 802.11b standard?It is one of the IEEE standards for wireless networks. The 802.11b standardallows wireless networking hardware from different manufacturers to commu-nicate, provided that the hardware complies with the 802.11b standard. The802.11b standard states a maximum data transfer rate of 11Mbps and an oper-ating frequency of 2.4GHz.What IEEE 802.11a features are supported?The product supports the following IEEE 802.11a functions: • OFDM protocol • Multi-Channel Roaming • Automatic Rate Selection • RTS/CTS feature • Fragmentation• Transmission Power Control• Dynamic Frequency Selection What IEEE 802.11b features are supported?The product supports the following IEEE 802.11b functions: • CSMA/CA plus Acknowledge protocol • Multi-Channel Roaming • Automatic Rate Selection • RTS/CTS feature • Fragmentation • Power Management What is ad-hoc mode?When a wireless network is set to ad-hoc mode, the wireless-equipped com-puters are configured to communicate directly with each other. The ad-hocwireless network will not communicate with any wired network. What is infrastructure mode?When a wireless network is set to infrastructure mode, the wireless network isconfigured to communicate with a wired network through a wireless accesspoint.If DMZ Hosting is used, does the exposed user share the public IP with the Router?No.Does the Router pass PPTP packets or actively route PPTP sessions? The Router allows PPTP packets to pass through, supporting up to five ses-sions.Is the Router cross-platform compatible? Any platform that supports Ethernet and TCP/IP is compatible with the Router.How many ports can be simultaneously forwarded? Theoretically, the Router can establish 520 sessions at the same time, but youcan only forward 10 ranges of ports.Does the Router replace a modem? Is there a cable or DSL modem in the Router?No, the Router must work in conjunction with a cable or DSL modem.Which modems are compatible with the Router? The Router is compatible with virtually any cable or DSL modem that supportsEthernet.What are the advanced features of the Router?The Router’s advanced features include Advanced Wireless settings, Filtering,Port Forwarding, Routing, DMZ Hosting, and MAC Address Cloning.How can I check whether I have static or DHCP IP Addresses?Consult your ISP to obtain this information. How do I get mIRC to work with the Router?Under the Port Forwarding tab, set port forwarding to 113 for the PC on whichyou are using mIRC.Can the Router act as my DHCP server?Yes. The Router has DHCP server software built-in.Can I run an application from a remote computer over the wireless network?This will depend on whether or not the application is designed to be used overa network. Consult the application’s documentation to determine if it supportsoperation over a network.
noise. There are two main alternatives, Direct Sequence Spread Spectrum(DSSS) and Frequency Hopping Spread Spectrum (FHSS).What is DSSS? What is FHSS? And what are their differences?Frequency-Hopping Spread-Spectrum (FHSS) uses a narrowband carrier thatchanges frequency in a pattern that is known to both transmitter and receiver.Properly synchronized, the net effect is to maintain a single logical channel. Toan unintended receiver, FHSS appears to be short-duration impulse noise.Direct-Sequence Spread-Spectrum (DSSS) generates a redundant bit patternfor each bit to be transmitted. This bit pattern is called a chip (or chippingcode). The longer the chip, the greater the probability that the original data canbe recovered. Even if one or more bits in the chip are damaged during trans-mission, statistical techniques embedded in the radio can recover the originaldata without the need for retransmission. To an unintended receiver, DSSSappears as low power wideband noise and is rejected (ignored) by most nar-rowband receivers. Will the information be intercepted while it is being transmitted through the air?WLAN features two-fold protection in security. On the hardware side, as withDirect Sequence Spread Spectrum technology, it has the inherent security fea-ture of scrambling. On the software side, WLAN offers the encryption function(WEP) to enhance security and access control.What is WEP?WEP is Wired Equivalent Privacy, a data privacy mechanism based on a 64-bitor 128-bit shared key algorithm, as described in the IEEE 802.11 standard.What is a MAC Address?The Media Access Control (MAC) address is a unique number assigned by themanufacturer to any Ethernet networking device, such as a network adapter,that allows the network to identify it at the hardware level. For all practical pur-poses, this number is usually permanent. Unlike IP addresses, which canchange every time a computer logs onto the network, the MAC address of adevice stays the same, making it a valuable identifier for the network.How do I avoid interference?If you are using the Router and one or more Access Points in close proximityto one another, and they are set on the same channel, interference will be gen-erated. To avoid interference, be sure to set the Router and all Access Points todifferent channels (frequencies); in other words, assign a unique channel to theRouter and each Access Point.87Instant Wireless®Series86Dual-Band Wireless A+G Broadband Router What is roaming?Roaming is the ability of a portable computer user to communicate continu-ously while moving freely throughout an area greater than that covered by a sin-gle access point. Before using the roaming function, the workstation must makesure that it is the same channel number with the access point of dedicated cov-erage area. To achieve true seamless connectivity, the wireless LAN must incorporate anumber of different functions. Each node and access point, for example, mustalways acknowledge receipt of each message. Each node must maintain contactwith the wireless network even when not actually transmitting data. Achievingthese functions simultaneously requires a dynamic RF networking technologythat links access points and nodes. In such a system, the user’s end node under-takes a search for the best possible access to the system. First, it evaluates suchfactors as signal strength and quality, as well as the message load currentlybeing carried by each access point and the distance of each access point to thewired backbone. Based on that information, the node next selects the rightaccess point and registers its address. Communications between end node andhost computer can then be transmitted up and down the backbone.As the user moves on, the end node’s RF transmitter regularly checks the sys-tem to determine whether it is in touch with the original access point or whetherit should seek a new one. When a node no longer receives acknowledgmentfrom its original access point, it undertakes a new search. Upon finding a newaccess point, it then re-registers, and the communication process continues.What is ISM band?The FCC and their counterparts outside of the U.S. have set aside bandwidthfor unlicensed use in the ISM (Industrial, Scientific and Medical) band.Spectrum in the vicinity of 2.4 GHz, in particular, is being made availableworldwide. This presents a truly revolutionary opportunity to place convenienthigh-speed wireless capabilities in the hands of users around the globe. What is Spread Spectrum?Spread Spectrum technology is a wideband radio frequency technique devel-oped by the military for use in reliable, secure, mission-critical communica-tions systems. It is designed to trade off bandwidth efficiency for reliability,integrity, and security. In other words, more bandwidth is consumed than in thecase of narrowband transmission, but the trade-off produces a signal that is, ineffect, louder and thus easier to detect, provided that the receiver knows theparameters of the spread-spectrum signal being broadcast. If a receiver is nottuned to the right frequency, a spread-spectrum signal looks like background
Dual-Band Wireless A+G Broadband Router 89Appendix B: How to Ping Your ISP’sE-mail & Web AddressesVirtually all Internet addresses are configured with words or characters (e.g.,www.linksys.com, www.yahoo.com, etc.) In actuality, however, these Internetaddresses are assigned to IP addresses, which are the true addresses on theInternet. For example, www.yahoo.com is 66.218.71.87 (this IP address maychange). Type it into your web browser and you will wind up at the Linksyshome page every time. There are servers that translate the URL to an IPaddress; this is called the Domain Name System (DNS).IP and web addresses, however, can sometimes be long and hard to remember.Because of this, certain ISPs will shorten their server addresses to single wordsor codes on their users’ web browser or e-mail configurations. If your ISP’s e-mail and web server addresses are configured with single words (www, e-mail,home, pop3, etc.) rather than whole Internet addresses or IP addresses, theRouter may have problems sending or receiving mail and accessing theInternet. This happens because the Router has not been configured by your ISPto accept their abbreviated server addresses.The solution is to determine the true web addresses behind your ISPs codewords. You can determine the IP and web addresses of your ISP’s servers by“pinging” them.Important: If you don’t have your ISP’s web and e-mail IPaddresses, you must either get them from your ISP or follow thesesteps prior to connecting the Router to your network.Instant Wireless®Series88How do I reset the Router?Press the Reset button on the back panel for about ten seconds. This will resetthe Router to its default settings.How do I resolve issues with signal loss?There is no way to know the exact range of your wireless network without test-ing. Every obstacle placed between the Router and a wireless PC will createsignal loss. Lead glass, metal, concrete floors, water and walls will inhibit thesignal and reduce range. Start with the Router and your wireless PC in thesame room and move it away in small increments to determine the maximumrange in your environment. You may also try using different channels, as this may eliminate interferenceaffecting only one channel. Also, due to FCC regulations, more power may betransmitted, using 802.11a, on channels 52, 56, 60 and 64, than on the lowerchannels. Lastly, click the Advanced tab of the web-based utility and makesure that FULL is selected in the Transmission Power field.I have excellent signal strength, but I cannot see my network. WEP is probably enabled on the Router, but not on your wireless adapter (orvice versa). Verify that the same WEP keys and levels (64, 128, or 152) arebeing used on all nodes of your wireless network. How many channels/frequencies are available with the Router?Using 802.11a, there are eight available channels, ranging from 36 to 64.Using 802.11g-draft, there are eleven available channels, ranging from 1 to 11. What is the difference in rangebetween 802.11a and 802.11gproducts?Overall, range will be a littleless in a typical environment,and while higher speeds may beachieved with 802.11a, through-put degrades more quickly. (SeeFigure A-1.)If your questions are not addressed here, refer to the Linksys website,www.linksys.com.Figure A-1
Dual-Band Wireless A+G Broadband Router 9190Step Two: Pinging for a Web AddressWhile the IP address returned above would work as your e-mail server address,it may not be permanent. IP addresses change all the time. Web addresses, how-ever, usually don’t. Because of this, you’re likely to have fewer problems byconfiguring your system with web addresses rather than IP addresses. Followthe instructions below to find the web address assigned to the IP address youjust pinged.1. At the DOS command prompt, type ping -a 24.53.32.4, where 24.53.32.4is the IP address you just pinged. Information such as the following datawill be displayed.C:\>ping -a 24.53.32.4Pinging mail.msnv3.occa.home.com [24.53.32.4] with32 bytes of data:Reply from 24.53.32.4: bytes=32 time<10ms TTL=127Reply from 24.53.32.4: bytes=32 time<10ms TTL=127Reply from 24.53.32.4: bytes=32 time<10ms TTL=127Reply from 24.53.32.4: bytes=32 time<10ms TTL=127Ping statistics for 24.53.32.4:Packets: Sent = 4, Received = 4, Lost = 0 (0%loss),Approximate round trip times in milli-seconds:Minimum = 0ms, Maximum = 0ms, Average = 0ms2. Write down the web address returned by the ping command. (In the exam-ple in Figure C-2, mail.msnv3.occa.home.com is the web address.) Thisweb address is the web address assigned to the IP address you just pinged.While the IP address of mail could conceivably change, it is likely that thisweb address will not.3. Replace your ISP’s abbreviated server address with this extended webaddress in the corresponding Internet application (web browser, e-mailapplication, etc.).Once you have replaced the brief server address with the true server address,the Router should have no problem accessing the Internet through that Internetapplication.Figure B-2Instant Wireless®SeriesStep One: Pinging an IP AddressThe first step to determining your ISP’s web and e-mail server address is toping its IP address.1. Power on the computer and the cable or DSL modem, and restore the net-work configuration set by your ISP if you have since changed it.2. Click Start and then Run. Type command in the Open field. This willbring up the DOS window.3. At the DOS command prompt, type ping mail (assuming that the locationfor which you’re trying to find an IP address is configured as mail). Pressthe Enter key. Information such as the following data, taken from a ping ofMicrosoft Network’s e-mail server, will be displayed.C:\>ping mailPinging mail [24.53.32.4] with 32 bytes of data:Reply from 24.53.32.4: bytes=32 time<10ms TTL=128Reply from 24.53.32.4: bytes=32 time<10ms TTL=128Reply from 24.53.32.4: bytes=32 time<10ms TTL=128Reply from 24.53.32.4: bytes=32 time<10ms TTL=128Ping statistics for 24.53.32.4:Packets: Sent = 4, Received = 4, Lost = 0 (0%loss),Approximate round trip times in milli-seconds:Minimum = 0ms, Maximum = 0ms, Average = 0ms4. Write down the IP address returned by the ping command (in the exampleabove: 24.53.32.4.). This IP address is the actual IP address of the servermail, or any other word or value you have pinged.Figure B-1
Dual-Band Wireless A+G Broadband Router 9392There are two types of WEP encryption for 802.1x, static and dynamic. StaticWEP keys are more vulnerable and can only be changed manually on alldevices, including the Router. If you are using MD5 authentication, then youcan only use static WEP keys. Dynamic WEP keys are keys that are renewedautomatically on a periodic basis. This makes the WEP key(s) more difficult tobreak, so network security is strengthened. To enable dynamic WEP keys, youmust use 802.1x certificate-based authentication methods, such as TLS orTTLS.Make sure your wireless network is functioning before attempting to configureWEP encryption.On a wireless network, a 128-bit WEP encrypted device will NOT communi-cate with a 64-bit WEP encrypted device. Therefore, make sure that all of thewireless devices on each network are using the same encryption level. In addition to enabling WEP, Linksys also recommends the following securityimplementations:•Change the SSID from the default “linksys”•Change the SSID on a regular basis•Change the WEP key regularly•Enable MAC address filtering (if your wireless products allow it)For instructions on how to configure the Router’s WEP settings, go to the“Setup” section of “Chapter 7: The Router’s Web-Based Utility.” For instruc-tions on how to configure the WEP settings of your PC’s wireless adapter, referto your wireless adapter’s documentation.WEP EncryptionInstant Wireless®SeriesAppendix C: Configuring WirelessSecurityThe Router offers two wireless security features. The basic feature is WiredEquivalent Privacy (WEP) encryption, an encryption method used to protectyour wireless data communications. WEP uses 64-bit, 128-bit, or 152-bit keysto provide access control to your network and encryption security for everydata transmission. To decode a data transmission, each point in a network mustuse an identical key. Higher encryption levels mean higher levels of security,but due to the complexity of the encryption, they may mean decreased networkperformance.You may also have heard the term “40-bit” used in conjunction with WEPencryption. This is simply another term for 64-bit WEP encryption. This levelof WEP encryption has been called 40-bit because it uses a 40-bit secret keyalong with a 24-bit Initialization Vector (40 + 24 = 64). Wireless vendors mayuse either name. Linksys uses the term “64-bit” when referring to this level ofencryption.The second wireless security feature is 802.1x. The IEEE 802.1x standard spec-ifies authentication methods for a wireless client, such as a PC, to access a net-work, so network security is enhanced. Based on the Extensible AuthenticationProtocol (EAP), 802.1x designates how a client accesses a network server, fre-quently a RADIUS server, with the Router acting as an authenticator. When anetwork uses 802.1x, the identity of the client is verified before the client isallowed network access. For example, a wireless user may use one of the authentication methods toaccess a wireless network protected by an authentication server. The user’s PCsends a request to the Router (an access point can be used instead). The Routersends an identification request back to the PC. After the PC sends the Router theidentification message, the Router forwards the identification message to theserver. If the server accepts the identification message, then the PC is permittedaccess to the wireless network.BackgroundNote: WEP encryption is an additional data security measure and notessential for router operation; however, Linksys recommends the useof WEP encryption.
Dual-Band Wireless A+G Broadband Router 3. Write down the Adapter Address as shown on your computer screen (seeFigure E-3). This is the MAC address for your Ethernet adapter and willbe shown as a series of numbers and letters. The MAC address/Adapter Address is what you will use for MAC addresscloning or MAC filtering. Write down the IP Address as shown on your computer screen. The exam-ple in Figure E-3 shows the IP address of your Ethernet adapter as192.168.1.100. Your computer may show something different. For Windows NT, 2000, and XP:1. Click Start and Run. In the Open field, enter cmd. Press the Enter key orclick the OK button.95Appendix D: Finding the MACAddress and IP Address for YourEthernet AdapterThis section describes how to find the MAC address for your Ethernet adapterto do either MAC address filtering or MAC address cloning for the Router andISP. You can also find the IP address of your computer’s Ethernet adapter. TheIP address is used for filtering, forwarding, and DMZ. Follow the steps in thisappendix to find the MAC address or IP address for your adapter in Windows95, 98, Me, NT, 2000, and XP. For Windows 95, 98, and Me:1. Click on Start and Run. In the Open field, enter winipcfg. Then press theEnter key or the OK button.2. When the IP Configuration window appears, select the Ethernet adapteryou are using to connect to the Router via a Category 5 Ethernet networkcable.94Figure D-3Figure D-4Note: The MAC address is also called the AdapterAddress.Instant Wireless®SeriesFigure D-1Figure D-2
Dual-Band Wireless A+G Broadband Router 972. In the command prompt, enter ipconfig /all. Then press the Enter key.3. Write down the Physical Address as shown on your computer screen; it isthe MAC address for your Ethernet adapter. This will appear as a series ofletters and numbers. The MAC address/Physical Address is what you will use for MAC addresscloning or MAC filtering. Write down the IP Address as shown on your computer screen. The exam-ple in Figure E-5 shows the IP address of your Ethernet adapter as192.168.1.100. Your computer may show something different. 96Appendix E: Glossary802.11a - One of the IEEE standards for wireless networking hardware.Products that adhere to a specific IEEE standard will work with each other,even if they are manufactured by different companies. It specifies a maximumdata transfer rate of 54Mbps and an operating frequency of 5GHz. The 802.11astandard uses the Orthogonal Frequency Division Multiplexing (OFDM) trans-mission method. Additionally, the 802.11a standard supports 802.11 featuressuch as WEP encryption for security.802.11b - One of the IEEE standards for wireless networking hardware.Products that adhere to a specific IEEE standard will work with each other,even if they are manufactured by different companies. The 802.11b standardspecifies a maximum data transfer rate of 11Mbps, an operating frequency of2.4GHz, and WEP encryption for security. 802.11b networks are also referredto as Wi-Fi networks.802.11g - A proposed, but as yet unratified extension of the IEEE 802.11 stan-dard for wireless networking hardware. The draft 802.11g specifications usedby Linksys specify a maximum data transfer rate of 54Mbps using OFDMmodulation, an operating frequency of 2.4GHz, backward compatibility withIEEE 802.11b devices, and WEP encryption for security.802.1x - Based on the Extensible Authentication Protocol (EAP), the 802.1xstandard is one of the IEEE standards for network authentication and key man-agement. It establishes a framework that supports multiple authentication meth-ods. This standard can be incorporated into any type of network to enhance itssecurity. For example, a wireless user may use one of the authentication methods toaccess a wireless network protected by an authentication server. The user, alsocalled the supplicant, sends a request to an access point or wireless router, alsocalled the authenticator. The authenticator sends an identification request backto the user. After the user sends the authenticator the identification message,the authenticator forwards the user's identification message to the authentica-tion server. If the server accepts the identification message, then the user is per-mitted access to the wireless network. The 802.1x standard can also supportencryption key management to strengthen wireless network encryption servic-es.Instant Wireless®SeriesFigure D-5Note: The MAC address is also called the PhysicalAddress.
Dual-Band Wireless A+G Broadband Router 99Adapter - Printed circuit board that plugs into a PC to add to capabilities orconnectivity to a PC. In a networked environment, a network interface card isthe typical adapter that allows the PC or server to connect to the intranet and/orInternet.Ad-hoc Network - An ad-hoc network is a group of computers, each with awireless adapter, connected as an independent 802.11 wireless LAN. Ad-hocwireless computers operate on a peer-to-peer basis, communicating directlywith each other without the use of an access point. Ad-hoc mode is alsoreferred to as an Independent Basic Service Set or as peer-to-peer mode.ADSL (Asymmetric Digital Subscriber Line) - A technology for transmittingdigital information at a high bandwidth on existing phone lines to homes andbusinesses. Unlike regular dialup phone service, ADSL provides continuously-available, "always on" connection. ADSL is asymmetric in that it uses most ofthe channel to transmit downstream to the user and only a small part to receiveinformation from the user. ADSL simultaneously accommodates analog (voice)information on the same line. ADSL is generally offered at downstream datarates from 144 Kbps to about 6 Mbps. A form of ADSL, known as UniversalADSL or G.lite, has been approved as a standard by the ITU-TS. ADSL was specifically designed to exploit the one-way nature of most multi-media communication in which large amounts of information flow toward theuser and only a small amount of interactive control information is returned.Several experiments with ADSL to real users began in 1996. In 1998, wide-scale installations began in several parts of the U.S. In 2000 and beyond, ADSLand other forms of DSL are expected to become generally available in urbanareas. With ADSL (and other forms of DSL), telephone companies are com-peting with cable companies and their cable modem services.AppleTalk - An Apple Computer networking system that supports Apple's pro-prietary local talk.Auto-MDI/MDIX - On a network hub or switch, an auto-MDI/MDIX portautomatically senses if it needs to act as a MDI or MDIX port. The auto-MDI/MDIX capability eliminates the need for crossover cables.Auto-negotiate - To automatically determine the correct settings. The term isoften used with communications and networking. For example, Ethernet10/100 cards, hubs and switches can determine the highest speed of the nodethey are connected to and adjust their transmission rate accordingly.98Backbone - The part of a network that connects most of the systems and net-works together and handles the most data.Bandwidth - The transmission capacity of a given facility, in terms of howmuch data the facility can transmit in a fixed amount of time; expressed in bitsper second (bps).Beacon Interval - A beacon is a packet broadcast by the Access Point to keepthe network synchronized. A beacon includes the wireless LAN service area,the AP address, the Broadcast destination addresses, a time stamp, DeliveryTraffic Indicator Maps, and the Traffic Indicator Message (TIM).Bit - A binary digit. The value - 0 or 1-used in the binary numbering system.Also, the smallest form of data.Boot - To cause the computer to start executing instructions. Personal comput-ers contain built-in instructions in a ROM chip that are automatically executedon startup. These instructions search for the operating system, load it and passcontrol to it. Broadband - A data-transmission scheme in which multiple signals share thebandwidth of a medium. This allows the transmission of voice, data and videosignals over a single medium. Cable television uses broadband techniques todeliver dozens of channels over one cable.Browser - A browser is an application program that provides a way to look atand interact with all the information on the World Wide Web or PC. The word"browser" seems to have originated prior to the Web as a generic term for userinterfaces that let you browse text files online. Buffer - A buffer is a shared or assigned memory area used by hardwaredevices or program processes that operate at different speeds or with differentsets of priorities. The buffer allows each device or process to operate withoutbeing held up by the other. In order for a buffer to be effective, the size of thebuffer and the algorithms for moving data into and out of the buffer need to beconsidered by the buffer designer. Like a cache, a buffer is a "midpoint holdingplace" but exists not so much to accelerate the speed of an activity as to sup-port the coordination of separate activities. Cable Modem - A device that connects a computer to the cable television net-work, which in turn connects to the Internet. Once connected, cable modemusers have a continuous connection to the Internet. Cable modems featureInstant Wireless®Series
Dual-Band Wireless A+G Broadband Router 101asymmetric transfer rates: around 36 Mbps downstream (from the Internet tothe computer), and from 200 Kbps to 2 Mbps upstream (from the computer tothe Internet).CAT 5 - ANSI/EIA (American National Standards Institute/ElectronicIndustries Association) Standard 568 is one of several standards that specify"categories" (the singular is commonly referred to as "CAT") of twisted paircabling systems (wires, junctions, and connectors) in terms of the data ratesthat they can sustain. CAT 5 cable has a maximum throughput of 100 Mbps andis usually utilized for 100BaseTX networks.Cookie - Data created by a Web server that is stored on a user's computer. Itprovides a way for the Web site to keep track of a user's patterns and prefer-ences and, with the cooperation of the Web browser, to store them on the user'sown hard disk.CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance) - In localarea networking, this is the CSMA technique that combines slotted time-divi-sion multiplexing with carrier sense multiple access/collision detection(CSMA/CD) to avoid having collisions occur a second time. This works best ifthe time allocated is short compared to packet length and if the number of sit-uations is small.CTS (Clear To Send) - An RS-232 signal sent from the receiving station to thetransmitting station that indicates it is ready to accept data.Daisy Chain - Connected in series, one after the other. Transmitted signals goto the first device, then to the second and so on.DDNS (Dynamic Domain Name System) - Allows a network device with adynamic Internet IP address to have a fixed host and domain name, such asmyhostname.mydomainname.com. It is useful when you are hosting your ownwebsite, FTP server, or other server behind a router, so people can find yoursite no matter how often the Internet IP address changes. Using DDNS requiresregistering with a DDNS service provider on the Internet.Default Gateway - The routing device used to forward all traffic that is notaddressed to a station within the local subnet.DHCP (Dynamic Host Configuration Protocol) - A protocol that lets networkadministrators manage centrally and automate the assignment of InternetProtocol (IP) addresses in an organization's network. Using the Internet's set of100protocol (TCP/IP), each machine that can connect to the Internet needs aunique IP address. When an organization sets up its computer users with a con-nection to the Internet, an IP address must be assigned to each machine.Without DHCP, the IP address must be entered manually at each computer and,if computers move to another location in another part of the network, a new IPaddress must be entered. DHCP lets a network administrator supervise and dis-tribute IP addresses from a central point and automatically sends a new IPaddress when a computer is plugged into a different place in the network. DHCP uses the concept of a "lease" or amount of time that a given IP addresswill be valid for a computer. The lease time can vary depending on how long auser is likely to require the Internet connection at a particular location. It's espe-cially useful in education and other environments where users change fre-quently. Using very short leases, DHCP can dynamically reconfigure networksin which there are more computers than there are available IP addresses. DHCP supports static addresses for computers containing Web servers thatneed a permanent IP address. DMZ (Demilitarized Zone) - Allows one IP address (or computer) to beexposed to the Internet. Some applications require multiple TCP/IP ports to beopen. You should set your computer with a static IP address if you want to useDMZ Hosting.DNS - The domain name system (DNS) is the way that Internet domain nameare located and translated into Internet Protocol (IP) addresses. A domain nameis a meaningful and easy-to-remember "handle" for an Internet address. Domain - A subnetwork comprised of a group of clients and servers under thecontrol of one security database. Dividing LANs into domains improves per-formance and security.Download - To receive a file transmitted over a network. In a communicationssession, download means receive, upload means transmit. DSL (Digital Subscriber Line) - A technology that dramatically increases thedigital capacity of ordinary telephone lines into the home or office and, byemploying unused bandwidth, still allows for normal phone usage. DSL pro-vides "always-on" operation, eliminating the need to dial in to the service.DSSS (Direct-Sequence Spread Spectrum) - DSSS generates a redundant bitpattern for all data transmitted. This bit pattern is called a chip (or chippingInstant Wireless®Series
Dual-Band Wireless A+G Broadband Router 103code). Even if one or more bits in the chip are damaged during transmission,statistical techniques embedded in the receiver can recover the original datawithout the need for retransmission. To an unintended receiver, DSSS appearsas low power wideband noise and is rejected (ignored) by most narrowbandreceivers. However, to an intended receiver (i.e. another wireless LAN end-point), the DSSS signal is recognized as the only valid signal, and interferenceis inherently rejected (ignored).DTIM (Delivery Traffic Indication Message) - A DTIM field is a countdownfield informing clients of the next window for listening to broadcast and mul-ticast messages. When the AP has buffered broadcast or multicast messages forassociated clients, it sends the next DTIM with a DTIM Interval value. APClients hear the beacons and awaken to receive the broadcast and multicastmessages.Dynamic IP Address - An IP address that is automatically assigned to a clientstation in a TCP/IP network, typically by a DHCP server. Network devices thatserve multiple users, such as servers and printers, are usually assigned static IPaddresses. Dynamic Routing - The ability for a router to forward data via a different routebased on the current conditions of the communications circuits. For example,it can adjust for overloaded traffic or failing lines and is much more flexiblethan static routing, which uses a fixed forwarding path.EAP (Extensible Authentication Protocol) - An IETF standard that establishesan authentication protocol for network access. Many authentication methods,including passwords, certificates, and smart cards, work within this framework.Encryption - A security method that applies a specific algorithm to data inorder to alter the data's appearance and prevent other devices from reading theinformation. Ethernet - IEEE standard network protocol that specifies how data is placedon and retrieved from a common transmission medium. Has a transfer rate of10 Mbps. Forms the underlying transport vehicle used by several upper-levelprotocols, including TCP/IP and XNS.Fast Ethernet - A 100 Mbps technology based on the 10Base-T EthernetCSMA/CD network access method.102FHSS (Frequency Hopping Spread Spectrum) - FHSS continuously changes(hops) the carrier frequency of a conventional carrier several times per secondaccording to a pseudo-random set of channels. Because a fixed frequency is notused, and only the transmitter and receiver know the hop patterns, interceptionof FHSS is extremely difficult.Finger - A UNIX command widely used on the Internet to find out informa-tion about a particular user, such as telephone number, whether currentlylogged on or the last time logged on. The person being "fingered" must haveplaced his or her profile on the system. Fingering requires entering the fulluser@domain address.Firewall - A firewall is a set of related programs, located at a network gatewayserver, that protects the resources of a network from users from other networks.(The term also implies the security policy that is used with the programs.) Anenterprise with an intranet that allows its workers access to the wider Internetinstalls a firewall to prevent outsiders from accessing its own private dataresources and for controlling what outside resources to which its own usershave access. Basically, a firewall, working closely with a router, examines each networkpacket to determine whether to forward it toward its destination.Firmware - Code that is written onto read-only memory (ROM) or program-mable read-only memory (PROM). Once firmware has been written onto theROM or PROM, it is retained even when the device is turned off.Fragmentation - Breaking a packet into smaller units when transmitting overa network medium that cannot support the original size of the packet. FTP (File Transfer Protocol) - A protocol used to transfer files over a TCP/IPnetwork (Internet, UNIX, etc.). For example, after developing the HTML pagesfor a Web site on a local machine, they are typically uploaded to the Web serv-er using FTP.FTP includes functions to log onto the network, list directories and copy files.It can also convert between the ASCII and EBCDIC character codes. FTP oper-ations can be performed by typing commands at a command prompt or via anFTP utility running under a graphical interface such as Windows. FTP transferscan also be initiated from within a Web browser by entering the URL precededwith ftp://.Instant Wireless®Series
Dual-Band Wireless A+G Broadband Router 105Unlike e-mail programs in which graphics and program files have to be"attached," FTP is designed to handle binary files directly and does not add theoverhead of encoding and decoding the data.Full Duplex - The ability of a device or line to transmit data simultaneously inboth directions.Gateway - A device that interconnects networks with different, incompatiblecommunications protocols. Half Duplex - Data transmission that can occur in two directions over a singleline, but only one direction at a time.Hardware - Hardware is the physical aspect of computers, telecommunica-tions, and other information technology devices. The term arose as a way to dis-tinguish the "box" and the electronic circuitry and components of a computerfrom the program you put in it to make it do things. The program came to beknown as the software.Hop - The link between two network nodes.HTTP (HyperText Transport Protocol) - The communications protocol usedto connect to servers on the World Wide Web. Its primary function is to estab-lish a connection with a Web server and transmit HTML pages to the clientbrowser.Hub - The device that serves as the central location for attaching wires fromworkstations. Can be passive, where there is no amplification of the signals; oractive, where the hubs are used like repeaters to provide an extension of thecable that connects to a workstation.ICQ - A conferencing program for the Internet that provides interactive chat,e-mail and file transfer and can alert you when someone on your predefined listhas also come online. IEEE (The Institute of Electrical and Electronics Engineers) - The IEEEdescribes itself as "the world's largest technical professional society, promotingthe development and application of electrotechnology and allied sciences forthe benefit of humanity, the advancement of the profession, and the well-beingof our members." 104The IEEE fosters the development of standards that often become national andinternational standards. The organization publishes a number of journals, hasmany local chapters, and several large societies in special areas, such as theIEEE Computer Society.Infrastructure Network - An infrastructure network is a group of computersor other devices, each with a wireless adapter, connected as an 802.11 wirelessLAN. In infrastructure mode, the wireless devices communicate with eachother and to a wired network by first going through an access point. An infra-structure wireless network connected to a wired network is referred to as aBasic Service Set (BSS). A set of two or more BSS in a single network isreferred to as an Extended Service Set (ESS). Infrastructure mode is useful ata corporation scale, or when it is necessary to connect the wired and wirelessnetworks.IP (Internet Protocol) - The method or protocol by which data is sent from onecomputer to another on the Internet. It is a standard set of rules, procedures, orconventions relating to the format and timing of data transmission between twocomputers that they must accept and use to be able to understand each other.IP Address - In the most widely installed level of the Internet Protocol (IP)today, an IP address is a 32-binary digit number that identifies each sender orreceiver of information that is sent in packet across the Internet. When yourequest an HTML page or send e-mail, the Internet Protocol part of TCP/IPincludes your IP address in the message (actually, in each of the packets if morethan one is required) and sends it to the IP address that is obtained by lookingup the domain name in the Uniform Resource Locator you requested or in thee-mail address you're sending a note to. At the other end, the recipient can seethe IP address of the Web page requestor or the e-mail sender and can respondby sending another message using the IP address it received. IPCONFIG - A Windows NT or 2000 utility that provides for querying, defin-ing and managing IP addresses within a network. A commonly used utility forconfiguring networks with static IP addresses.IPSec (Internet Protocol Security) - A suite of protocols used to implementsecure exchange of packets at the IP layer. IPSec supports two basic modes:Transport and Tunnel. Transport encrypts the payload of each packet, leavingthe header untouched, while Tunnel mode encrypts both the header and the pay-load and is therefore more secure. IPSec must be supported on both transmit-ter and receiver and must share a public key. Tunnel mode is widely deployedin VPNs (Virtual Private Networks).Instant Wireless®Series
Dual-Band Wireless A+G Broadband Router 107IPX (Internetwork Packet EXchange) - A NetWare communications protocolused to route messages from one node to another. IPX packets include networkaddresses and can be routed from one network to another.ISM band - The FCC and their counterparts outside of the U.S. have set asidebandwidth for unlicensed use in the ISM (Industrial, Scientific and Medical)band. Spectrum in the vicinity of 2.4 GHz, in particular, is being made avail-able worldwide. This presents a truly revolutionary opportunity to place con-venient high-speed wireless capabilities in the hands of users around the globe.ISP (Internet Service Provider) - A company that provides individuals andcompanies access to the Internet and other related services such as Web sitebuilding and virtual hosting. LAN (Local Area Network) - A group of computers and associated devices thatshare a common communications line and typically share the resources of asingle processor or server within a small geographic area (for example, withinan office building). Layer 2 - Data Link layer in the International Standards Organization (ISO) 7-Layer Data Communications Protocol, also known as the OSI (Open SystemsInterconnection) model. This is a standard model to consult when designingnetwork protocols. Layer 2 is directly related to the hardware interface for net-work devices and passes traffic based on MAC addresses.MAC (Media Access Control) Address - A unique number assigned by themanufacturer to any Ethernet networking device, such as a network adapter,that allows the network to identify it at the hardware level.Mbps (Megabits per second) - One million bits per second; unit of measure-ment for data transmission.MD5 - A type of one-way authentication method that uses passwords. MD5authentication is not as secure as the EAP-TLS or EAP/TTLS authenticationmethods. MD5 authentication does not support dynamic WEP key manage-ment.MDI (Medium Dependent Interface) - On a network hub or switch, a MDIport, also known as an uplink port, connects to another hub or switch using astraight-through cable. To connect a MDI port to a computer, use a crossovercable.106MDIX (Medium Dependent Interface Crossed) - On a network hub or switch,a MDIX port connects to a computer using a straight-through cable. To connecta MDIX port to another hub or switch, use a crossover cable.mIRC - mIRC runs under Windows and provides a graphical interface for log-ging onto IRC servers and listing, joining and leaving channels.Multicasting - Sending data to a group of nodes instead of a single destination.NAT (Network Address Translation) - The translation of an Internet Protocoladdress (IP address) used within one network to a different IP address knownwithin another network. One network is designated the inside network and theother is the outside. Network - A system that transmits any combination of voice, video and/or databetween users. NNTP (Network News Transfer Protocol) - The protocol used to connect toUsenet groups on the Internet. Usenet newsreaders support the NNTP protocol.Node - A network junction or connection point, typically a computer or workstation.Notebook (PC) - A notebook computer is a battery-powered personal comput-er generally smaller than a briefcase that can easily be transported and conve-niently used in temporary spaces such as on airplanes, in libraries, temporaryoffices, and at meetings. A notebook computer, sometimes called a laptop com-puter, typically weighs less than five pounds and is three inches or less in thick-ness. OFDM - Developed for wireless applications, Orthogonal Frequency DivisionMultiplexing (OFDM) technology offers superior performance-increased datarates and more reliable transmissions-than previous technologies, such asDSSS. OFDM is a scheme in which numerous signals of different frequenciesare combined to form a single signal for transmission on the medium. OFDM works by breaking one high-speed data stream into a number of lower-speed data streams, which are then transmitted in parallel. Each lower speedstream is used to modulate a subcarrier. Essentially, this creates a multi-carriertransmission by dividing a wide frequency band or channel into a number ofnarrower frequency bands or sub-channels. OFDM is also used for other appli-cations, including powerline networking.Instant Wireless®Series
Dual-Band Wireless A+G Broadband Router 109108used in 802.1x implementations; however, they are not specified by the 802.1xstandard.RJ-45 (Registered Jack-45) - A connector similar to a telephone connector thatholds up to eight wires, used for connecting Ethernet devices.RMON (Remote MONitoring) - RMON provides comprehensive networkmonitoring capabilities. It eliminates the polling required in standard SNMP,and can set alarms on a variety of traffic conditions, including specific errortypes.Roaming - In an infrastructure mode wireless network, this refers to the abili-ty to move out of one access point's range and into another and transparentlyreassociate and reauthenticate to the new access point. This reassociation andreauthentication should occur without user intervention and ideally withoutinterruption to network connectivity. A typical scenario would be a locationwith multiple access points, where users can physically relocate from one areato another and easily maintain connectivity.Router - Protocol-dependent device that connects subnetworks together.Routers are useful in breaking down a very large network into smaller subnet-works; they introduce longer delays and typically have much lower throughputrates than bridges. RTS (Request To Send) - An RS-232 signal sent from the transmitting stationto the receiving station requesting permission to transmit. Server - Any computer whose function in a network is to provide user accessto files, printing, communications, and other services. SMTP (Simple Mail Transfer Protocol) - The standard e-mail protocol on theInternet. It is a TCP/IP protocol that defines the message format and the mes-sage transfer agent (MTA), which stores and forwards the mail.SNMP (Simple Network Management Protocol) - A widely used networkmonitoring and control protocol. Data is passed from SNMP agents, which arehardware and/or software processes reporting activity in each network device(hub, router, bridge, etc.) to the workstation console used to oversee the net-work. The agents return information contained in a MIB (ManagementInformation Base), which is a data structure that defines what is obtainablefrom the device and what can be controlled (turned off, on, etc.).Instant Wireless®SeriesPacket - A unit of data routed between an origin and a destination in a network.Passphrase - Used much like a password, a passphrase simplifies the WEPencryption process by automatically generating the WEP encryption keys forLinksys products.Ping (Packet INternet Groper) - An Internet utility used to determine whethera particular IP address is online. It is used to test and debug a network by send-ing out a packet and waiting for a response.POP3 (Post Office Protocol 3) - A standard mail server commonly used on theInternet. It provides a message store that holds incoming e-mail until users logon and download it. POP3 is a simple system with little selectivity. All pendingmessages and attachments are downloaded at the same time. POP3 uses theSMTP messaging protocol.Port - A pathway into and out of the computer or a network device such as aswitch or router. For example, the serial and parallel ports on a personal com-puter are external sockets for plugging in communications lines, modems andprinters. PPPoE (Point to Point Protocol over Ethernet) - PPPoE is a method for theencapsulation of PPP packets over Ethernet frames from the user to the ISPover the Internet. One reason PPPoE is preferred by ISPs is because it providesauthentication (username and password) in addition to data transport. A PPPoEsession can be initiated by either a client application residing on a PC, or byclient firmware residing on a modem or router.PPTP (Point-to-Point Tunneling Protocol) - A protocol which allows the Pointto Point Protocol (PPP) to be tunneled through an IP network. PPTP does notspecify any changes to the PPP protocol but rather describes a "tunneling serv-ice" for carrying PPP (a tunneling service is any network service enabled bytunneling protocols such as PPTP, L2F, L2TP, and IPSEC tunnel mode). Oneexample of a tunneling service is secure access from a remote small office net-work to a headquarters corporate intranet via a Virtual Private Network (VPN)that traverses the Internet. However, tunneling services are not restricted to cor-porate environments and may also be used for personal (i.e., non-business)applications.RADIUS (Remote Authentication Dial-In User Service) - A protocol used tocontrol network access. RADIUS enables servers to authenticate users, so onlylegitimate users are granted network access. RADIUS servers are frequently
Dual-Band Wireless A+G Broadband Router TCP (Transmission Control Protocol) - A method (protocol) used along withthe IP (Internet Protocol) to send data in the form of message units (datagram)between network devices over a LAN or WAN. While IP takes care of handlingthe actual delivery of the data (routing), TCP takes care of keeping track of theindividual units of data (called packets) that a message is divided into for effi-cient delivery over the network. TCP is known as a "connection oriented" pro-tocol due to requiring the receiver of a packet to return an acknowledgment ofreceipt to the sender of the packet resulting in transmission control.TCP/IP (Transmission Control Protocol/Internet Protocol) - The basic com-munication language or set of protocols for communications over a network(developed specifically for the Internet). TCP/IP defines a suite or group ofprotocols and not only TCP and IP.Telnet - A terminal emulation protocol commonly used on the Internet andTCP/IP-based networks. It allows a user at a terminal or computer to log ontoa remote device and run a program.TFTP (Trivial File Transfer Protocol) - A version of the TCP/IP FTP protocolthat has no directory or password capability.Throughput - The amount of data moved successfully from one place toanother in a given time period.UDP (User Datagram Protocol) - A method (protocol) used along with the IP(Internet Protocol) to send data in the form of message units (datagram)between network devices over a LAN or WAN. While IP takes care of handlingthe actual delivery of the data (routing), UDP takes care of keeping track of theindividual units of data (called packets) that a message is divided into for effi-cient delivery over the network. UDP is known as a "connection-less" protocoldue to NOT requiring the receiver of a packet to return an acknowledgment ofreceipt to the sender of the packet (as opposed to TCP).Upgrade - To replace existing software or firmware with a newer version. Upload - To transmit a file over a network. In a communications session,upload means transmit, download means receive. URL (Uniform Resource Locator) - The address that defines the route to a fileon the Web or any other Internet facility. URLs are typed into the browser toaccess Web pages, and URLs are embedded within the pages themselves to pro-vide the hypertext links to other pages.111Software - Instructions for the computer. A series of instructions that performsa particular task is called a "program." The two major categories of software are"system software" and "application software." System software is made up ofcontrol programs such as the operating system and database management sys-tem (DBMS). Application software is any program that processes data for theuser.A common misconception is that software is data. It is not. Software tells thehardware how to process the data.Spread Spectrum - Spread Spectrum technology is a wideband radio frequen-cy technique developed by the military for use in reliable, secure, mission-crit-ical communications systems. It is designed to trade off bandwidth efficiencyfor reliability, integrity, and security. In other words, more bandwidth is con-sumed than in the case of narrowband transmission, but the trade off producesa signal that is, in effect, louder and thus easier to detect, provided that thereceiver knows the parameters of the spread-spectrum signal being broadcast.If a receiver is not tuned to the right frequency, a spread-spectrum signal lookslike background noise. There are two main alternatives, Direct SequenceSpread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS).SSID (Service Set IDentifier) - A unique name shared among all points in awireless network. The SSID must be identical for each point in the wireless net-work and is case-sensitive. Static IP Address - A permanent IP address that is assigned to a node in an IPor a TCP/IP network. Static Routing - Forwarding data in a network via a fixed path. Static routingcannot adjust to changing line conditions as can dynamic routing. Storage - The semi-permanent or permanent holding place for digital data. Subnet Mask - The method used for splitting IP networks into a series of sub-groups, or subnets. The mask is a binary pattern that is matched up with the IPaddress to turn part of the host ID address field into a field for subnets. Switch - 1. A data switch connects computing devices to host computers,allowing a large number of devices to share a limited number of ports. 2. Adevice for making, breaking, or changing the connections in an electrical cir-cuit.110Instant Wireless®Series
Dual-Band Wireless A+G Broadband Router 113Appendix F: SpecificationsStandards 802.11a, 802.11b, draft 802.11gPortsInternet: One 10/100 RJ-45 Port for Cable/DSL ModemLAN: Four 10/100 RJ-45 Switched PortsButtons One Reset Button and One Power PortCabling Type UTP Category 5 or betterLEDs Power, DiagInternet: Link/Act, 100LAN: Link/Act, Full/Col, 100802.11a: Act, Link54g: Act, LinkVPN (Virtual Private Network) - A technique that allows two or more LANs tobe extended over public communication channels by creating private commu-nication subchannels (tunnels). Effectively, these LANs can use a WAN as asingle large "virtually private" LAN. This removes the need to use leased linesfor WAN communications through secure use of a publicly available WAN(such as the Internet). Examples of VPN technology are: PPTP (Point to PointTunneling Protocol), L2TP (Layer 2 Tunneling Protocol), and IPSec (InternetProtocol Security).WA N (Wide Area Network)- A communications network that covers a rela-tively large geographic area, consisting of two or more LANs. Broadband com-munication over the WAN is often through public networks such as the tele-phone (DSL) or cable systems, or through leased lines or satellites. In its mostbasic definition, the Internet could be considered a WAN.WEP (Wired Equivalent Privacy) - A data privacy mechanism based on a 64-bit or 128-bit shared key algorithm, as described in the IEEE 802.11 standard. WINIPCFG - Configuration utility based on the Win32 API for querying,defining and managing IP addresses within a network. A commonly used util-ity for configuring networks with static IP addresses.WLAN (Wireless Local Area Network) - A group of computers and associat-ed devices that communicate with each other wirelessly.112Instant Wireless®Series
Dual-Band Wireless A+G Broadband Router 115Dimensions 7.32" x 1.89" x 6.89" (186 mm x 48 mm x 175 mm)Unit Weight 0.88 lbs. (0.4 kg)Power External, 5V DC, 2.5ACertifications FCC, CE Marking, Wi-FiOperating Temp. 32ºF to 104ºF (0ºC to 40ºC) Storage Temp. -4ºF to 158ºF (-20ºC to 70ºC) Operating Humidity 10% to 85%, Non-CondensingStorage Humidity 5% to 90%, Non-Condensing 114Appendix G: Warranty InformationBE SURE TO HAVE YOUR PROOF OF PURCHASE AND A BARCODEFROM THE PRODUCT'S PACKAGING ON HAND WHEN CALLING.RETURN REQUESTS CANNOT BE PROCESSED WITHOUT PROOF OFPURCHASE. IN NO EVENT SHALL LINKSYS’S LIABILITY EXCEED THE PRICEPAID FOR THE PRODUCT FROM DIRECT, INDIRECT, SPECIAL, INCI-DENTAL, OR CONSEQUENTIAL DAMAGES RESULTING FROM THEUSE OF THE PRODUCT, ITS ACCOMPANYING SOFTWARE, OR ITSDOCUMENTATION. LINKSYS DOES NOT OFFER REFUNDS FOR ANYPRODUCT. LINKSYS OFFERS CROSS SHIPMENTS, A FASTER PROCESS FOR PRO-CESSING AND RECEIVING YOUR REPLACEMENT. LINKSYS PAYSFOR UPS GROUND ONLY. ALL CUSTOMERS LOCATED OUTSIDE OFTHE UNITED STATES OF AMERICA AND CANADA SHALL BE HELDRESPONSIBLE FOR SHIPPING AND HANDLING CHARGES. PLEASECALL LINKSYS FOR MORE DETAILS.Instant Wireless®SeriesEnvironmental
Appendix H: Contact InformationFor help with the installation or operation of the Dual-Band Wireless A+GBroadband Router, contact Linksys Technical Support at one of the phone num-bers or Internet addresses below.Sales Information 800-546-5797 (1-800-LINKSYS)Technical Support 800-326-7114RMA Issues 949-271-5461Fax 949-265-6655Email support@linksys.comWeb site http://www.linksys.comFTP site ftp://ftp.linksys.com116© Copyright 2003 Linksys, All Rights Reserved.www.linksys.comInstant Wireless®Series

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