[c-nsp] Ethernet autonegotiation issue between Cat3560 and Cat2960

[Juuso Lehtinen]

Hi,

I have Catalyst 3560 and 2960 switches connected by a two member
Etherchannel trunk using built in copper GE interfaces. For some reason
Ethernet autonegotiation ends up assigning unmatching speeds for one link
(10M in one switch, 100M in other) and the interfaces end up in suspended
state.

MGMT-14#show int status | inc 35|36
Gi0/35                       connected    trunk      a-full a-1000
10/100/1000BaseTX
Gi0/36                       suspended    trunk      a-full  a-100
10/100/1000BaseTX

MGMT-13#show int status | inc 23|24
Gi0/23                       connected    trunk      a-full a-1000
10/100/1000BaseTX
Gi0/24                       suspended    trunk      a-full   a-10
10/100/1000BaseTX

Any ideas what might be causing this. I wonder if I'm running into some kind
of minimum cable length problem. Switches are sitting adjacent to each other
in a rack and connected with very short cables (0.5m ~ 2 ft).

-Juuso Lehtinen