One that seems to be pretty good is Network Flight Recorder ( http://www.nfr.com ). This can run on an affordable Intel or Sparc box,
and for internal private use, it's free (and somewhat limited in speed).
There are also some (free) modules for it at loPht ( http://www.L0pht.com
-- make sure you get L"zero"pht.com, or you'll get a nice surprise).
NFR is a general-purpose platform for network analysis and reporting, but
it seems that right now it is most well-known for security analysis and
detection. The cool thing about it is that you can write your own modules
(that's one of the intents of the samples at L0pht.com).
[ On Sun, January 10, 1999 at 17:50:34 (-0700), Pete Kruckenberg wrote: ]
Subject: Re: Net Flows and Analysis tools
>
> I am looking for some real-time net flow and analysis tools.
One that seems to be pretty good is Network Flight Recorder
( http://www.nfr.com ).
Another I don't think has been mentioned yet is ntop-1.0. It's not
anywhere near as fancy or sophisticated or programmable as NFR, but
depending on your goals and requirements, it can do quite a bit for such
a small program. The new version has an HTML interface that is quite
useful for its size.