[ILUG] Network monitoring tools in Linux

[Braun E. Brelin]

Hello,

I'm looking for some tools for a network analysis for a potential
customer.  I already have tcpdump and
mrtg.  What other open source tools are available?   I'd really like
something that works along the lines of
NetMetrix or a Network General sniffer (i.e. a good packet analyzer) as
well as something that monitors applications.

Does anyone know of anything along these lines?

Thanks,

Braun Brelin