CertificationZone Page 1 of 4 http://www.certificationzone.com/studyguides /?Issue=37&IssueDate=05-01-2001&CP= 11/06/01 Date of Issue: 05-01-2001 Lab Scenario 2: Configuring A Terminal Server by David Wolsefer Introduction Equipment Needed Configuration Tasks Using the Terminal Server Final Configuration Introduction This lab teaches the reader to configure and use a terminal server such as a Cisco 2509 or 2511. Although this is a relatively simple lab, mastery of this material is critically important. If you cannot fully configure a terminal server in five minutes or less, then you do not know this material well enough. This particular lab is important because, once you have mastered the ability to build a terminal server quickly, you can work on your other practice scenarios much more efficiently. Upon completion of this lab, you will have a direct console connection to every router and switch in your lab. Moving around between different routers and switches will become much faster and easier. One question that people often ask is whether they should obtain a 2509 or a 2511 for their home lab. It doesn't matter too much. I prefer the 2511 because you can have 16 console connections with this model. With the 2509, you can only have eight console connections, and some people's labs have more than eight different pieces of equipment. Equipment Needed 1. A terminal server such as a Cisco 2509 or 2511 2. One or two octopus cables, depending upon which terminal server you have. You may also see terminal servers that use standard RJ-45 connectors. Here is a picture of an octopus cable. Note that each line is terminated with an RJ-45 connector and is labeled 1-8 so that you know which connector corresponds to a given reverse-telnet port such as 2001-2008. (Click for a larger view.) Figure 1. Octopus Cable 3. One or more additional routers. Attach the octopus cable's RJ-45 connectors into the console ports. Configuration Tasks This lab is a walk-through scenario. We will configure and check each step along the way. The first task is to write erase and reload your terminal server. This configures the router to the state it had fresh out of the box. The next step is to configure a loopback interface and assign it an IP address. I like to use 1.1.1.1 for an IP address. It doesn't matter what you are using for an IP address or mask, so you might as well make it a /32 mask. For example: CertificationZone Page 2 of 4 http://www.certificationzone.com/studyguides /?Issue=37&IssueDate=05-01-2001&CP= 11/06/01 Terminal_Server #conf t Terminal_Server (config)#interface loopback 0 Terminal_Server (config-if)#ip address 1.1.1.1 255.255.255.255 The next step is to create an IP host table for each router or switch to which the terminal server is connected. Each router is assigned a reverse Telnet port corresponding to the cable number plugged into its console port. Note that the octopus cable has each port marked on the octopus cable. Since a 2509 only has eight console plugs, the corresponding reverse Telnet ports are numbered 2001-2008. A 2511 would use ports 2001-2016. We will use this information in constructing the IP host table. Following is a sample IP host table: ip host r1 2001 1.1.1.1 ip host r2 2002 1.1.1.1 ip host r3 2003 1.1.1.1 ip host r4 2004 1.1.1.1 ip host r5 2005 1.1.1.1 ip host r6 2006 1.1.1.1 ip host cat5000 2007 1.1.1.1 Notice how each router or switch is listed in the host table with a reference to the host name, the reverse telnet port, and the IP address of the loopback interface. The final step is to enter line configuration mode and enter the transport method for all eight or 16 lines. It is very important that you specify a method that allows for reverse telnet. I tend to use the command transport input all, but you could use transport input telnet. For example: Terminal_Server #conf t Terminal_Server (config)#line 1 8 Terminal_Server (config)#transport input all Using the Terminal Server Once the configuration steps are complete, it is time to try out the terminal server. Enter the hostname of a router listed in the IP host table at the prompt and press enter. Following is an example of what you will see: Terminal_Server #r1 Trying r1 (1.1.1.1, 2001) Open Router> If you see a message similar to the one below, you will need to check the status of the lines of the terminal server using the show line command. Terminal_Server #r1 Trying r1 (1.1.1.1, 2001) % Connection refused by remote host. Once you have successfully reverse telneted into another router, enter <ctrl+shift+6> x to return to the terminal server. Now check the status of the lines on the terminal server. You should see something similar to the following: Terminal_Server#show line Terminal_Serverf#show line Tty Typ Tx/Rx A Modem Roty AccO AccI Uses Noise Overruns Int - * 0 CTY - - - - - 7 0 0/0 - * 1 TTY 9600/9600 - - - - - 0 0 0/2 - * 2 TTY 9600/9600 - - - - - 1 1 0/0 - * 3 TTY 9600/9600 - - - - - 1 0 0/0 - * 4 TTY 9600/9600 - - - - - 1 0 0/0 - * 5 TTY 9600/9600 - - - - - 1 0 0/0 - * 6 TTY 9600/9600 - - - - - 1 0 0/0 - * 7 TTY 9600/9600 - - - - - 1 0 0/0 - * 8 TTY 9600/9600 - - - - - 1 1 0/0 - 9 AUX 9600/9600 - - - - - 0 0 0/0 - 10 VTY - - - - - 0 0 0/0 - 11 VTY - - - - - 0 0 0/0 - 12 VTY - - - - - 0 0 0/0 - CertificationZone Page 3 of 4 http://www.certificationzone.com/studyguides /?Issue=37&IssueDate=05-01-2001&CP= 11/06/01 13 VTY - - - - - 0 0 0/0 - 14 VTY - - - - - 0 0 0/0 - The asterisk indicates that this particular line is in use. If a line is shown to be in use and you know that it should not be, just use the clear line n command. If you want to rapidly clear all lines at once, you can just exit from the terminal server using the exit command. Another useful command is the show sessions command. This command displays a connection number for each host, which provides you with a shortcut. Assume that we had used the terminal server to connect to r1-r4 and the Catalyst 5000. Instead of typing out the host name every time, we could just use the session number to move between sessions. The table should look something like this: Terminal_Server #show sessions Conn Host Address Byte Idle Conn Name 1 r1 1.1.1.1 0 0 r1 2 r2 1.1.1.1 0 0 r2 3 r3 1.1.1.1 0 0 r3 4 r4 1.1.1.1 0 0 r4 5 cat 1.1.1.1 0 0 cat This is where the timesaving part comes in. When I initially connect to routers from a terminal server, I reverse telnet to them in order that 1 = r1, 2 = r2, etc. In this case, if I wanted to connect to the Catalyst, I would just enter a 5 instead of typing cat. If I want to disconnect a single session, I can use the disconnect session-# command. If you want to exit all sessions at once, just use the exit command. Final Configuration Here is the final configuration for the terminal server. The critical parts of the configuration are highlighted. version 11.3 service nagle ! hostname Terminal_Server ! ip subnet-zero ! interface Loopback0 ip address 1.1.1.1 255.255.255.255 ! interface Ethernet0 no ip address shutdown ! interface Serial0 no ip address shutdown ! interface Serial1 no ip address shutdown ! ip host r1 2001 1.1.1.1 ip host r2 2002 1.1.1.1 ip host r3 2003 1.1.1.1 ip host r4 2004 1.1.1.1 ip host r5 2005 1.1.1.1 ip host r6 2006 1.1.1.1 ip host cat5 2007 1.1.1.1 ! ip classless ! line con 0 exec-timeout 5 0 privilege level 15 line 1 8 transport input all line aux 0 line vty 0 4 exec-timeout 5 0 CertificationZone Page 4 of 4 http://www.certificationzone.com/studyguides /?Issue=37&IssueDate=05-01-2001&CP= 11/06/01 privilege level 15 no login ! end [IE-LabS-LS2-F03] [2001-04-26-01] Copyright © 2001 Genium Publishing Corporation . Configuration Introduction This lab teaches the reader to configure and use a terminal server such as a Cisco 25 09 or 25 11. Although this is a relatively. server such as a Cisco 25 09 or 25 11 2. One or two octopus cables, depending upon which terminal server you have. You may also see terminal servers that