We are having an issue with our Cisco Phones - This affects all models that we have seen (7941,7961,7970, 7937, and 7936 models) the phone will go out and basically it locks the network port out. The phone will not reregister till you move it to a different port on the swtich. Any Ideas out there on why this is going on?
There is no known issue as such, you can check the status messages or the phone console logs on some phones where the issue is likely to happen ( you must have identified a switch by now where it is happening the most ), also check for any switchport errors. Try concentrating on a single site / switch / phone model to begin with to narrow down the issue so that troubleshooting is easy. It may also require packet captures from the switchports where the issue occurs with the captures running all the time until the issue is actually reported. Do check for any recent changes on the network specially any config or ios changes on the switches to which the phones are connected.