Ethereal-users: RE: [Ethereal-users] Could Ethereal monitor bad-packet COUNTS in linux?
Peter,
> Is it possible, (and has anyone attempted) to monitor these
> bad- packet counts, and record "virtual bad packets" in the ethereal
> data stream when bad data is detected?
I do all the time, but I don't use Ethereal to do it. I use MRTG and I poll
MIB II variables such as
ifInNUcastPkts, ifInDiscards, ifInErrors,
ifOutUcastPkts,
ifOutDiscards, ifOutErrors, ifOutQLen,
I also poll CPU, memory, byte and frame counts and any other performance
metric I think could be important. Only when I see something interesting in
the MRTG graphs do I use Ethereal to get more detail.
Start off by looking at the management information provided by your
switches, routers, hubs and servers.
- Are all your NICs correctly guessing or explicitly configured at the right
speed, half/full duplex, MTU etc?
- Do you know what "normal" is for your LAN (eg collisions are normal on a
hub but may indicate a problem on a switch)?
- Have you configured and are you receiving SNMP Traps when thresholds are
breached?
I wrote a little rant about this earlier that might be useful.
http://www.ethereal.com/lists/ethereal-users/200302/msg00031.html
Having said that, Ethereal does offer some very useful display filters terms
such as ip.checksum_bad, ip.fragment.error, tcp.segment.error etc.
HTH
Cheers
Alistair
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