[c-nsp] 3560 switch VLAN SNMP issues

[Doug McIntyre]

We have a 3560 running layer-3 routing and VLAN terminations, and have
major problems getting valid SNMP data off the thing for per VLAN
traffic.

Data comes in trunked in one of the SFP ports, and terminates into a
layer-3 VLAN routed out. We see the VLAN interface in the SNMP tables
(ie. for VLAN #700)

IF-MIB::ifOutOctets.700 = Counter32: 668699
IF-MIB::ifInOctets.700 = Counter32: 1470625768

but the data isn't consistant. It doesn't seem to be measuring squat
for out bytes, they should be much closer to in bytes (and these
counters haven't rolled yet).

We've tried pretty much every IOS version released for this switch,
and have seen the same behavior for every release.

Measuring SNMP data for each physical port seems to work just fine,
but none of the VLAN interfaces work. 

We do an extremely simular config on the 4500 platform with zero problems.

Any suggestions?