[c-nsp] 50% intermittent packet loss on Cisco IP Phone connected to Cat4500

[Roger Wiklund]

Scenario, Cisco 6921 IP phone connected to Cat4500 with IOS
12.2(54)SG1 Port has CDP, dot1x, QoS trust enabled etc.
When I ping from another subnet I get about 50% packetloss with no
obvious pattern. Phone drops registration to the callmanger, releases
IP and restarts, and cycles through it over and over.

No PC is connected behind the phone. And PCs on the same switch have
no problems what so ever.
I tried to remove dot1x and just have a clean port, but still with the
same issue.

Moved the phone to a 2960 switch, worked right away.

I then disabled CDP on the 4500 port and it looks better but to early to tell.
Did not find anything like this in the bugtool for 12.2(54)SG1.

Have you seen anything like this before on the 4500?

Thanks