CCNA 2: Routing Protocols and Concepts configuring routers, help

Shake_Zula

I am working on a lab for class that involves configuring 3 routers using rip protocol and loop backs. I need to be able to telnet from router 1 to router 2-3 or vice versa. The image shows 5 routers, but we are only using 3. We are not using any switches or more than 1 computer, just 3 routers. Routers: Lab_B,Lab_C,Lab_D

We are using Cisco 1721 routers



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The teacher does something to the routers before he gave them to us for the lab. I can't get the serial 0 interface to go to UP. No shutdown makes it do to admin down.

Lab_B#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Lab_B(config)#interface serial 0
Lab_B(config-if)#ip address 10.135.32.9 255.255.255.252
Lab_B(config-if)#clock rate 56000
Lab_B(config-if)#shutdown
Lab_B(config-if)#
*Mar 2 16:02:30.435: %LINK-5-CHANGED: Interface Serial0, changed state to admin
istratively down
Lab_B(config-if)#no shutdown
Lab_B(config-if)#
*Mar 2 16:02:49.167: %LINK-3-UPDOWN: Interface Serial0, changed state to down

I erased the start up and it was successful erasing the start up, but it would not change state to up when i did a no shutdown on serial 0. The teacher purposely does stuff like this when hands out the routers so we have to troubleshoot before we can really even start the lab.

I am configuring LAB_B,C,D from the table in the first post. I have router 1 connected to the terminal (my computer) and the other to console on router 1. Router 1 is connected to router 2 by a serial cable both on serial 0 of router 1 and 2. I switched the cables to serial 0 ,but it did not work either. I had router 2 and router 3 connected by Ethernet port (crossover cable). not sure what else to try...

Shake_Zula

Enter configuration commands, one per line. End with CNTL/Z.
Lab_B(config)#interface serial 1
Lab_B(config-if)#ip address 10.135.32.6 255.255.255.255
Bad mask /32 for address 10.135.32.6
Lab_B(config-if)#clock rate 56000
Lab_B(config-if)#interface serial 1
Lab_B(config-if)#ip address 10.135.32.6 255.255.255.252
Lab_B(config-if)#clock rate 56000
Lab_B(config-if)#no shutdown
Lab_B(config-if)#
*Mar 2 15:37:39.971: %LINK-3-UPDOWN: Interface Serial1, changed state to down

techyguy4

Can you paste the details of the below commands.
1. #show controllers serial 1
2. #show ip int brief
Also, check the encapsulation on both the ends.

Corndork2

Looks like no encapsulation. Set it to PPP or HDLC.

Can you post a show run?

Shake_Zula

thanks for the help guys

I am not in lab until Wednesday so I d not have access to the routers. I have to review our labs on encapsulation because I am really not familiar with how to set it.

I know you guys wont be able to help much without the #show run, controllers serial 1, but any ideas and suggestions will help. The teacher "mods" the routers like this before labs so I am sure its not a hardware issue. Can someone verify that I have the 3 routers connected correctly??

more details on how no encapsulation could cause this problem?