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 192.168.1.10 -wDebugTraffic.pcap

This will capture all traffic coming into port 80 from host 192.168.1.10 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: http://packetlife.net/media/library/12/tcpdump.pdf

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s