Hello all,
We have two Cisco CP-8841 VoIP phones connected to a Catalyst 2960-CX switch that reaches back to our core. Both phones worked as expected until Friday of last week. One phone (phone A), connected to G0/5 is no longer able to connect. The other phone (phone B), connected to G0/7 still functions as normal. For some reason, phone A will not pull an IP and the switch does not recognize the MAC, or any device connected to G0/5 with phone A connected, but does provide PoE to the phone.
Both ports have the same configuration settings.
We tried swapping phones A and B by putting A on G0/7 and B on G0/5. Phone B came right up, just like it did on G0/7 and phone A still failed to connect on G0/7. This confirmed that the problem was not the port or cable.
We connected phone A directly to the core switch and the phone connected like normal. Thinking that the problem was possibly fixed, we connected it back to G0/5 but it still failed to register. We confirmed that there were no IP DHCP Conflicts or Bindings so we could not figure out what is causing the problem.
We tried wiping the local switch and set it back to factory setting, then rebuilt the config but the phone still did not connect to the network. We then connected an HP-1820-8G switch to G0/5 and phone A to the HP switch and it came up with the correct IP and phone number settings.
We are baffled as to why the phone will work connected to any other switch on the network but just not when connected directly to single switch that it is supposed to connect to. Has anyone ever seen this problem before or have any ideas on what we might be able to do to correct it?
