On a 2950 switch with identical port config one phone do not send periodically cdp mesages (not checked on monitoring session, only with sh cdp nei command on the 2950 switch), which results trust device lost event.
it seems the phone tries to get IP address in the access vlan not in the voice vlan. (discards the cdp packet sent by the switch?)
This phone should autoregister to the ccm 4.1(3)sr5. Autoregistration works on other switches.
If I configure this phone on the ccm, it starts working, it sends cdp more often - in every 120 sec the the cdp hold time restarts.
What could be the source of this problem?