Network Monitoring: Favorite Software

I’m curious to hear what kind of network monitoring software is out there that I can use for free. Do you have a favoritve package that you really like? Let me know what’s popular and useful to you!

I like ethereal:

What exactly are you looking to do? One package may solve your requirements, while others may not.

I personally was never able to find a single freeware package that filled all of my needs, but a programs called SolarWinds (which my company paid for) filled most of them. (the important ones).

Are you looking for reporting? Simple up/down ping responses? Detailed usage via SNMP?

I’m basically looking for a performance monitor. I’d like to see, for instance, why the internet is slow on a particular day. I know its someone downloading or streaming movies/music I just can’t easily tell who and what it is. I’ll check out the tips above, thanks guys!