[f-nsp] sflow: Occasionally missing in_vlan

[Stefan Neufeind]

Hi,

I've been trying to use sflow on a BigIron 4000 (J-BxGMR4 with firmware
8.00.00b) with sflow v2 (the older standard, but the only available
until v7.x of the firmware) for accounting traffic based on ports/VLANs.
Most parts have been successful.

But I occasionally receive traffic from other routers that I know for
sure send traffic through a VLAN. The "inputPort" given in the flow is
correct, but in_vlan in those cases is simply "0". This does not appearr
for one remote router or VLAN only, but happens on a repeatable basis of
(it seems) randomly selected flows/packets.

Anybody seen this as well? Looks like my only chance now is to take the
srcMAC to know where traffic came from - but knowing the correct VLAN
was used would be much more helpful.


Regards,
 Stefan