[a-nsp] VLAN in SNMP Interface Table

[Doug McIntyre]

On Sun, Dec 08, 2019 at 06:02:47PM -0600, Mike Hammett wrote:
> This looks like it's only on layer 3 interfaces, which doesn't do me a whole lot of good. 


I don't know of any hardware that keeps track of layer-2 VLAN packet
counts going through the switch. Generally, stats are updated on times
when switches have to _do_ something. Forwarding along layer-2 is
usually done in ASICs and the switch doesn't do anything special for
decoding the VLAN headers. OOTH, doing a layer-3 routing termination
is doing something, which is where I measure everything, on the
layer-3 edge. And every type of hardware I touch can monitor that. 

As posted before, if you need this sort of thing, you'll probably have
to go to sflow type collectors in order to get what you want. Or
consider making your network do layer-3 VLAN terminations somewhere so
that you can measure it. 

Perhaps there is some weird EVPN/vxlan setup you could make that the
switch will have to do punting of traffic out to a VTEP, and you could
measure those counts, but I have zero experience monitoring such a setup.