Linux Packet Capture

If you need to debug traffic going to a linux server or appliance, you can use tcpdump to generate a pcap file you can analyze in wireshark.

For example, ssh into the server, and use the following command:

tcpdump -s0 port 80 and host -wDebugTraffic.pcap

This will capture all traffic coming into port 80 from host and saved as file DebugTraffic.pcap

You can then use an ftp program (like WinSCP) to grab the file and analyze it in wireshark.

Here is a great resource for tcpdump commands: