Serial Interface

[dcanady55]

Good Afternoon,

This is probably a basic question but one I'm having trouble finding any info on.

I have two routers and they have a point to point connection. I'm making some network maps and trying to document physical connections. On the one locations router there is only one T1 so I don't have to worry about that port. However, on the other end it goes into 2851 which has many T1's coming into it. When I look at the show run of the 2851 I get the following output for the location I'm looking to document.

interface Serial0/0/1:0

description "T1 to Pio (1)"

I did come across a command "show inventory" that gives me a lot of info but is there a way for me to remotely find out which exact port on the 2851 that this T1 comes into based of the output in blue above?

Thanks,

Derek

[bolds04]

Derek,

If I understand your question correctly, you should be able to do "Show CDP Neighbor" command on either side of the Point-to-Point link.  This will show what is connected and on what interface. 

Based on what you provided, the T1 is on port 1 on slot 0 card.  So depending on what card you have we know that it's on slot 0 and port 1.  Other than that we would need to know what module you have in the router. 

Hope this helps. 

Brandon

[dcanady55]

Thanks for the response. Based on you comment can you use the "show cdp neighbor" just on one interface or is this something that runs on all of them? I want to make sure I run this on only internal facing circuits for security sake.

Thanks,

[bolds04]

Derek,

When you run "Show CDP Neighbor" command it shows what Cisco devices directly connected that are also running CDP.  So if you have a device on the far side with CDP turned off then you won't see it. 

You can turn off CDP globally or on a per interface basis.  Let me know if this clears things up.