Keep Calm and take a tcpdump! :)

Tcpdump is just one of the tools that will make troubleshooting network issues, or testing applications, or even finding out what traffic is being generated on a host all that much easier.  This podcast is to help you understand the Tcpdump program, and how powerful it is...

http://danielmiessler.com/study/tcpdump/

http://www.thegeekstuff.com/2010/08/tcpdump-command-examples/

http://www.tecmint.com/12-tcpdump-commands-a-network-sniffer-tool/

http://www.amazon.com/TCP-Illustrated-Vol-Addison-Wesley-Professional/dp/0201633469

http://www.computerhope.com/unix/tcpdump.htm

http://www.commandlinefu.com/commands/using/tcpdump  -- excellent examples

http://www.amazon.com/Practical-Packet-Analysis-Wireshark-Real-World/dp/1593272669/

Intro "Private Eye", transition "Mining by Moonlight", and Outro "Honeybee" created by Kevin MacLeod (incompetech.com) 
Licensed under Creative Commons: By Attribution 3.0
http://creativecommons.org/licenses/by/3.0/