Tcpdump on Nokia firewall interface with VLAN tagging enabled

nohup tcpdump -i eth3c1 -s1500 -w /tmp/sungard.cap 'vlan X and (host Y.Y.Y.Y or host Z.Z.Z.Z )' &

You will see traffic between two hosts X.X.X.X and Y.Y.Y.Y. The "vlan X" has to be specified otherwise no traffic is seen by tcpdump.