Identify how switches are connected

[cisco1313]

What is the easiest way to determine how 2 Cisco switches are connected via trunk port to determine a network topology for a tree network? I can see the switches with 

show cdp neighbors detail

on both sides, but it's not clear which is the parent switch. Is it possible to determine which one is the parent switch and which one is the child switch?

[Kasun Bandara]

Hi

you can use 

show cdp neighbors

without 'details' word to get summery of neighbors. in there 'Local interface' is the port related to your current logged device. 'Port ID' is port for remote device. you can log in to remote device by using ip address details retrieved from 

show cdp neighbors details

command.

rate and mark as answer if you resolved your concern

[Seb Rupik · Accepted solution]

Hi there,

As you point out the cdp command only displays information about switches which are participating in CDP. It gives no detail regarding the topology beyond that which is directly attached.

Using your tree analogy it is not possible to determine if the attached switch is a smaller 'branch' or part of the 'trunk' . Arguably you could look at the switch model to determine the platform and make an educated guess regarding its use, ie, core, distribution, access.

Ultimately it won't be until the end of your exercise that you will have a full picture of your 'tree' and know which are the parents and children.

cheers,

Seb.

[cisco1313]

Thanks, I feared for that and it makes sense.