I'm installing a Data Discovery appliance soon and during testing noticed it was only seeing one side of an MSN messenger conversation. I plugged in a laptop directly to the switch and ran tcpdump. Sure enough I saw SYN and ACK, but no SYN/ACK in between. Although strangely enough the whole conversation was in the MSN client.
I then checked to make sure that on the 3750 it was monitoring both directions. It was configured for both directions. Everything checks out correct but I still only see one side of the conversation. It occurred to me it may have something to do with VLANs but that looks good as well.
Any suggestions? Thanks.