Hello Manolis,
I have seen this and use the following approach:
> a. either during capture (via linux tcpdump) or
Find out which interface the traffic will use. For example, if it is a server and bound to a particular IP, then find out which interface the IP is on. Then capture only on that interface. I understand that this is not always possible or might be difficult to find out. But, it's usually not impossible. For example, if you have eth0 and eth0.vlan_id, then using "-i any" is likely to capture the same traffic on both interfaces. Instead, you might want to use only "-i eth0.vlan_id"
> b. during display (take out the duplicate frames)?
Use a display filter like !(tcp.analysis.retransmission or tcp.analysis.duplicate_ack) combined with anything else protocol specific. This gets rid of most of the unwanted stuff (though might also hide genuine retransmissions).
Of course, I am also happy to find out a better method :)
Hope this helps.
Abhik.
