What could cause "show cdp nei" to no longer work after changing from switch access to trunking and vlans? I change my network from a single vlan (router with two secondary interfaces configured) with 3 subnets - -to 3 separate vlan interfaces and trunking. I have a combination of a 6513 wan router, 3550 lan router, Catalyst 3550 & 3524XL's. Before I made the change "sho cdp nei worked". After the change to trunks and vlans, "sh cdp nei" can not see any 3524XL's when they are by themselves. If there is a 3550 upstream or downstream from a 3524 XL then, "sh cdp nei" seems to work only on that link. I believe we are running the same version of CDP on all the lan switches. Everything is working as planned except "sh cdp nei".
In the case where there are qty 4 3524XL's connected by gigastack, which is then connected by fiber SX GBIC, you are suggesting to execute a clear int G0/X on each 3524XL and the corresponding port on the 3550-12T lan routing switch? ie all the way from the end of the stack to the lan routing switch. Please confirm.
Corrext ,try the 3524 end first and then wait a couple minutes until cdp can run . If that doesn't work do the same on the 3550 end . If you have to you can run a debug cdp on each and see if you are getting reply's from each end . If you have cdp active on every port though you will get a lot of messages . I would do this as a last resort.
Thanks for staying with me on this. I have gone thru my whole environment and cleared all the connecting interfaces, found a couple of interfaces run V2 cdp advert., changed everything to disable V2, cleared cdp counters. I noticed where "cdp nei" does not work, I do not see any cdp input - -but devices connected upstream and downstream are incrementing the cdp output counters. All the 3524XL are running the same version of IOS. It appears as tho there must be a 3550 in the connectivity stream to make cdp nei to work. I have another facility with 3534 and 3548 where the cdp nei works just fine. Any insight?
I have all my native vlans identical. It is strange that doing a "sh cdp traffic" indicates these devices are advertising, because I see the output counters increment, but the input counters are on "zero" yet. I have verified all devices are running V1 of cdp, cdp is enabled, and the 3524XL's can not be seen with cdp unless there is a 3550 somewhere in the path of the Xl's.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...