Any way to get an audio representation of packet flow?
dgl at dlee.org
Tue Jan 25 01:04:10 PST 2005
Ok, this may be odd to many, but here's what I want:
I like tcpdump's powerful ways of selecting and analyzing specific
portions of packet traffic, but I want a real-time way to represent
the results. I am blind, so graphs don't help. <grin> Usually all I
want to know is the pattern of packet match frequency vs. time, so a
little click for each matching packet would translate nicely into what
I'm looking for.
My normal tactic involves directing output from tcpdump to /dev/audio
or even /dev/pcaudio:
tcpdump -l -n [... rules for traffic ...] >/dev/audio
is the first trick I tried. Problem: It causes me to get kernel
errors like "runt packet" and such, presumably because it adds too
mmuch overhead to packet processing somehow. (This is a P166; maybe
that problem wouldn't exist on faster hardware?)
My next trick was like
tcpdump -s 1 -w /dev/audio [... rules for traffic ...]
No errors this time, but the output of -w is buffered regardless of -l
(which normally makes a lot of sense, of course), so it wasn't very
I currently run FreeBSD 4.10-STABLE, but I'd be interested in any
solutions requiring 5.x features as well, for future planning.
Please Cc me if you have any ideas.
Doug Lee dgl at dlee.org http://www.dlee.org
Bartimaeus Group doug at bartsite.com http://www.bartsite.com
The very smart may feel they have nothing to learn from anyone;
The very wise will find something to learn from everyone. (7/14/01)
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