A neat trick I picked up somewhere on the Internet (sorry for not referencing, I simply don't remember which site I stole it from :)).

In embedded work, one often has headless access to a target device off which one wants to sniff network packets. As Wireshark is so nice to use - and everything else is not - I've been using tcpdump on the target to dump traffic into a pcap file and then transferring to dissect offline. Turns out this is just plain dumb and that one can simply have tcpdump pipe the captures packets live to a remote Wireshark session.

All we have to to is create a FIFO file, run tcpdump remotely and have it output raw data to stdout, write stdout to the FIFO and have Wireshark pull from the FIFO: