INPUT_SNMP and OUTPUT_SNMP for non-mirrored interfaces

[simonemainardi]

trafficstars

current behavior:

• [--in-iface-idx|-u] fills INPUT_SNMP with the last two bytes of the MAC address of the flow sender.
• [--out-iface-idx|-Q] fills OUTPUT_SNMP with the last two bytes of the MAC address of the flow receiver.

The behavior above is consistent when the nprobe receives mirrored/netflow traffic as well as when the traffic goes through the nProbe host.

When a flow originates at the nProbe host, then INPUT_SNMP and OUTPUT_SNMP should be swapped:

• OUTPUT_SNMP is the local nProbe host interface used to send out the flow (sender mac address)
• INPUT_SNMP is the remote interface that will receive the flow (receiver mac address).