On Wed, Nov 6, 2013 at 8:03 PM, Jiří Baum <j...@baum.com.au> wrote:
> Hi,
> Jiří:
> >> Can anyone tell me what it means when I get the error message "Bogus
> >> PPPoE length field (1502)" a few hundred times a day, usually in
> >> bunches? Always the same number, 1502, never any other.
>
> Jeremy:
> > Have you tried negotiating a differently sized MTU to see if it changes
> > the length field displayed in the error message?
> No, I haven't... Part of the problem is that I don't know what triggers
> it, which makes it hard to debug. It appears from time to time in the
> log, usually in a bunch, but not associated with any activity that I've
> been able to notice.
find a nice area of space and run something like
#!/bin/bash
dmesg -c
cd /some/nice/area/of/space
while true; do
d=`date +%s`
tcpdump blah options -c 10000 -w tout-$d
if dmesg | grep "Bogus PPPoE length"; then
echo omg i think i found something | mail -s OMG y...@there.com
exit
fi
find -name "tout-*" -mmin +1440 -delete
done
run it in screen so it doesn't get hup'd if the ssh session closes.
completely untested, what it might do is
1. destroy your system.
2.
clear the contents of dmesg
write the contents of tcpdump to a file until it receives 10000 packets
(adjust number to suit)
then tcpdump will exit and then grep to see if the error message is present
on your system,
if it is, email you and exit the script. I'm guessing the error is present
in dmesg,
then delete files starting with tout- that are over a day or two old
then goto beginning of while
also, to possibly trigger the error, try scping a multi meg file to and
from the location, the point being to
get a full sized packet going over the link in both directions, not
necessarily at the same time.
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