CDP

[htaljaard]

Hi

I can see one of the neighbouring switches with CDP, even the IP address, but I cannot ping or connect to the switch.

What could be the cause of this?

[jgross]

Hi,

if you have a trunk between, check that the native vlan is the same on both sides.

Bye

Jo

[Richard Burts]

It would be very helpful to have more information. To start: what vlan is configured on the switch port which can see the other switch as CDP neighbor, what vlan is configured on the switch port of the other switch; what vlan is your management interface (interface sc0 on many switches) configured to be part of, and what is its IP address (especially important what is its network and subnet), and what about the management interface of the other switch (what vlan is it associated with and what is its IP address, subnet and network).

I suspect a mismatch in one or more of these things is the reason you can not ping or connect.

[smif101]

Remember that CDP works at layer 2 and you don't have to have layer 3 connectivity to see the information that is provided with CDP. You could have two routers connected via a serial link with misconfigured IP addresses, you won't be able to ping each other but you will see the CDP information.