topic CDP / LLDP display issue in Switches, Hubs, and Modems

CDP / LLDP display issue

Jay-D — Tue, 06 Apr 2010 08:19:45 GMT

Hi there,

While doing a "show cdp neighbors" or a "show lldp info remote-device" on two directly linked procurve switches I can only see the remote MAC address, not the system name :

KALAMAR1# sh cdp neighbors

CDP neighbors information

Port Device ID | Platform Capability
---- ----------------------------- + ---------------------------- -----------
1 00 1f fe 51 be 40 | ProCurve J9085A Switch 26... S

KALAMAR2# sh cdp neighbors

CDP neighbors information

Port Device ID | Platform Capability
---- ----------------------------- + ---------------------------- -----------
1 00 1f fe 51 60 80 | ProCurve J9085A Switch 26... S

I've seen this issue in many config. Do you know what can cause this?

Kind regards,
JD.

Re: CDP / LLDP display issue

Mohammed Faiz — Tue, 06 Apr 2010 13:19:02 GMT

Hi,

Depending upon what software versions you are running the CDP command isn't really valid anymore.
For example, if I run a "show cdp n" I only see the MAC of the connected switch but with a "sh ll i r" I see both the MAC address and the hostname (listed under 'SysName').
What software versions are you running on the switches in your example?

Re: CDP / LLDP display issue

Jay-D — Tue, 06 Apr 2010 13:26:41 GMT

You're right, we may have more info from the LLDP view :

KALAMAR1# sh ll i r

LLDP Remote Devices Information

LocalPort | ChassisId PortId PortDescr SysName
--------- + ------------------------- ------ --------- ----------------------
1 | 00 1f fe 51 be 40 1 1 KALAMAR2
26 | CORE(00110a-45d200) C2

now I have a mix of MAC address & Host names. On older IOS, the view is more user friendly with only the host name.

JD.

Re: CDP / LLDP display issue

Mohammed Faiz — Tue, 06 Apr 2010 13:40:55 GMT

If you just want something to show you a map of your switch inter-links try using Procurve Manager:

http://www.procurve.com/products/management/ProCurve_Manager/overview.htm

The basic version (not Procurve manager plus) is free and it will automatically create graphical maps of your network for you.

Re: CDP / LLDP display issue

Shadow13 — Tue, 06 Apr 2010 13:57:52 GMT

you can try
#show cdp neighbors detail

Re: CDP / LLDP display issue

Jay-D — Tue, 06 Apr 2010 14:05:37 GMT

This command :

#show cdp neighbors detail

..is giving the IP but not the hostname which didn't do the trick for me :(

I'm using PCM+ but I prefer using CLI to track switches interco in order to propagate VLANS. I'll stop using CDP and for the LLDP commands.

Thank you!