[1471] in linux-net channel archive
Re: UDP: bad checksum.
daemon@ATHENA.MIT.EDU (David Monro)
Sun Dec 3 02:42:16 1995
Date: Sun, 3 Dec 1995 14:19:25 +1100 (EST)
From: David Monro <davidm@cs.su.oz.au>
Reply-To: David Monro <davidm@cs.su.oz.au>
To: linux-kernel@vger.rutgers.edu, linux-net@vger.rutgers.edu
In-Reply-To: <m0tLM3F-0002zOC@wf-rch.rich.bnr.ca>
> > > The full message is:
> > > UDP: bad checksum. From 807F7E0B:520 to 807F7EFF:520 ulen 512
> > > although sometimes the ulen is 242.
This is some machine doing RIP protocol (/etc/services: route 520/udp #RIP)
> >
> > The messages I see are a little different:
> >
> > UDP: bad checksum. From 00000000:68 to FFFFFFFF:67 ulen 308
This is some machine doing an attempted bootp (source address is 0 because it
hasn't configured itself yet, source port is 68 (bootp client), target address
is broadcast, target port is 67 (bootp server). I get these quite often - I'm
fairly certain these are not the fault of the linux box (since I've seen a DEC
alpha running our experimental operating system here produce messages which I
think mean the same thing).
> >
> > It always the same message. Always. I traced the packets to one specific
> > machine, but I'm one a large network and have no way of tracking down
> > what type of machine it is (or even where it is.
If you have the ip address try a reverse lookup. If you have the ethernet
hardware address, try looking up the first octets in one of those lists of
ethernet hardware manufacturer prefixes (or mail me the enet address and I'll
do it).
> >
> > It's gotta be a Linux net problem specific to later 1.3.x kernels. The
> > messages go away in 1.2.13, and I've noticed them 1.3.x since 1.3.35 or
> > so.
Interesting - I get them on 1.2.13 and all 1.3.x kernels.
My guess is that in both cases some bogus hardware (eg router or terminal
server in the case of the bootp one, maybe a router in the other case) is
causing the problem, or maybe something with a bogus udp implementation.
David
