In search of the right tool(s)

[Marc Evans <marc () destek net>]

Hello -

I am looking for tools that I can setup to monitor network traffic,
ideally passively, which will try to detect and alert me to attacks or
suspicious activity _originating_ within my networks. I already have
several tools setup that detect activity targetting my networks, and now
want to make certain that knowbody launches anything from within the
address space that I am responsible for. For reference, I am working with
several /18, /19, and various smaller network blocks, often times
multi-homed through several geographically diverse methods.

Suggestions and references would be greatly appreciated.

Thanks in advance - Marc