CCNA Lab Serial WAN connection

[JAdams71]

Hello,

I am working on my CCNA and I have a small R&S lab setup with 2 1841 routers, 1 2811 router. The issue I am running into is all my routers have T1 DSU/CSU cards and I need to be able to simulate a serial WAN connection for labs. Is there a way to do this with the T1 cards or do I need to purchase serial cards and the DTE/DCE cables? 

[Georg Pauwen · Accepted solution]

Hello,

all you need is a T1 crossover cable, if you don't have one, you can make one yourself:

https://www.freeccnaworkbook.com/blog/ccna/how-to-make-a-t1-crossover

Then configure the interfaces as below:

R1
=====
interface Serial0/0
description BACK-TO-BACK T1 CONNECTION - CSU/DSU LINK 1544KBPS
ip address 192.168.1.1 255.255.255.0
service-module t1 timeslots 1-24
service-module t1 linecode b8zs
service-module t1 framing esf
service-module t1 clock source internal

R2
=====
interface Serial0/0
description BACK-TO-BACK T1 CONNECTION - CSU/DSU LINK 1544KBPS
ip address 192.168.1.2 255.255.255.0
service-module t1 timeslots 1-24
service-module t1 linecode b8zs
service-module t1 framing esf
service-module t1 clock source line

[JAdams71]

Georg,

Thank you for your reply. I have the crossover cables so I will give your solution a try. I was trying to set the clock rate on one interface for it work as the DCE side like you would with a serial connection and the DTE/DCE cable and that would not work. 

[Georg Pauwen]

Hello,

it should work. The important thing is to make sure that one side uses the line as the clock source, while the other uses 'internal'.

[JAdams71]

Thank you for your help. I was finally able to get around to testing it and I have connection between both routers on the t1 interfaces now.