[c-nsp] Problem polling VLAN infos via SNMPv3

[Phil Mayers]

jmnsp at loplof.de wrote:
> I'm trying to solve the following exercise in a scalable manner:
> 
> Retrieve the CAM table on a per VLAN basis from a 6500 running
> s72033-jk9sv-mz.122-18.SXD4.bin via SNMPv3.
> 
> The solution so far has been to create a context for each VLAN and
> allow access to this context. Allowing access requires one additional
> config line per VLAN and then retrieving:
> snmpwalk -v3 c6500r BRIDGE-MIB::dot1dTpFdbTable
> for the default VLAN/context (which just works) and
> snmpwalk -n vlan-2 -v3 c6500r BRIDGE-MIB::dot1dTpFdbTable
> which requires the following config line to grant access:
> snmp-server group admin v3 priv context vlan-2 access 99
> 
> This solution doesn't seem to scale too well, especially when the list
> of VLANs changes dynamically due to VTP. Is there any better solution
> than preconfiguring contexts for all (theoretically possible) VLANs?

snmpwalk -v 2c -c thereadcomm at 123 dot1dTpFdb

...replacing @123 with @thenumber of whichever vlan you're interested in.

More generally, anything under the dot1d table that's applicable (e.g. 
the STP values if you're running PVST) will return the values for that vlan.