analysing captured packets

Hi
Can anyone give any pointers to good tutorials on how to go about
analysing network traffic captured during a pen-test.

I'm currently using ethereal but I'm not necessarily looking for an
ethereal tutorial more a howto on what to look for in capture files.
Things like good protocols to spot (e.g. ftp logs in in plaintext so
you can grab login details), how to recognise what is going on by
watching the high level handshakes (e.g. a http get is usually
followed by a response containing html), things like that.

Thanks

Robin

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