High CPU on 3750 stack

[Pete89]

Hello,

I have been seeing high CPU on a 3750 stack we use for our phone system. I followed the documentation here:

http://www.cisco.com/en/US/docs/switches/lan/catalyst3750/software/troubleshooting/cpu_util.html#wp1034726

This documentation pointed out that the interrupt was very high and so I started looking at the CPU queues to debug. The icmp queue was dropping TONS of traffic.

The debug was full of these:

ICMP-Q:Dropped Not a candidate: Remote Port Blocked L3If:Vlan248 L2If:GigabitEthernet1/0/17 DI:0xB4, LT:7, Vlan:248   SrcGPN:17, SrcGID:17, ACLLogIdx:0x0, MacDA:001a.a1c4.1cd2, MacSA: 0013.192c.bb80   IP_SA:5.1.1.10 IP_DA:5.1.1.2 IP_Proto:17
   TPFFD:ECD2B811_00F800F8_00B000DA-000000B4_12AF0015_63E885C0

ICMP-Q:Dropped Not a candidate: Local Port Fwding L3If:Vlan248 L2If:GigabitEthernet2/0/52 DI:0xB4, LT:7, Vlan:248   SrcGPN:106, SrcGID:106, ACLLogIdx:0x0, MacDA:001a.a1c4.1cd2, MacSA: fcfb.fb34.b450   IP_SA:5.1.1.6 IP_DA:5.1.1.2 IP_Proto:17
   TPFFD:ECD2B86A_00F800F8_00B000DA-000000B4_54040015_63E885C0

I cant find anything about the message.The 5.1.1.x IPs belong to the voicegateways which are connected directly to ports 17 and 52. The rest of the Cisco phone system resides on the stack

Any ideas???

[michal.nehasil]

Hi, did you manage to figure this out? I've same symptoms on 3750 stack.

Thanks,

m.

[Leo Laohoo]

Would be nice to know what IOS all of you are running.

If you are running 15.0(1)SE (or later) or 15.0(2)SE, I'd recommend anyone to downgrade to 12.2(55)SE6.