I am having the same problem with a firewall which has been upgraded from 6.3 to 7.0(1) All VLAN interfaces are returning the interface statistics from the physical interface. Under 6.3 all VLANs returned individual statistics. The SNMP utility identifies the VLAN interfaces correctly. ThereforeI suspect something has changed in the SNMP implementation in 7.0(1) but I don't know how to go about investigating further.
I wish I could help more, but it may be useful to include details of the setups. This might help to eliminate potential issues, or highlight others.
Our setup is as follows:
PIX 515 running 7.0(1)
6 physical interfaces, one of these has 4 VLANs configured.
Collecting and graphing statistics using Cacti 0.8.5 running on RH9. I was considering upgrading Cacti, but I'm holding off because I feel the issue is more likely to be with the PIX code.
I've checked open and closed cavaets for 7.0(X) but can't see anything relevant.
Any thoughts anyone?