Security auditing tools

[Carlos Silva <carlosmiguel.silva () gmail com>]

Hello list,
I'm wondering what type of security auditing tools (open source) do we
have to perform some traffic analysis. I know that ethereal is
becoming more sophisticated, but it doesn't present the graphics as
some comercial tools, and i would like to see if anyone in here does
know some tool (or set of tools) to perform this type of job?
And, does anyone here knows where i can find a comparison between this
type of software and comercial software that do this type of job (like
Observer or Sniffer)?
Thanks in advance.
My best regards,

Carlos Silva