On Fri, Mar 18, 2005 at 04:59:40PM +0000, Patrick Welche wrote:
> On Fri, Mar 18, 2005 at 05:40:17PM +0100, Manuel Bouyer wrote:
> > On Fri, Mar 18, 2005 at 03:48:54PM +0000, Patrick Welche wrote:
> > > > Good point..
> > > 
> > > How about this:
> > > 
> > > 15:35:15.825614 IP (tos 0x0, ttl  63, id 4649, offset 0, flags [none], length: 240, bad cksum 0 (->8cda)!) quartz.newn.cam.ac.uk.domain > 192.168.203.45.1072:  51958 1/5/4 time.windows.com. A time.windows.com (212)
> > > 
> > > It comes from tcpdump running on a -current box between quartz.newn and
> > > 192.168.203.45. Is the bad checksum from quartz.newn, or because the box
> > > running tcpdump has an ex(4) with hardware checksumming? All seems to
> > > work, so I would guess the later.. (BTW nfs seems OK for me, but the loads
> > > are very low)
> > 
> > Where are you running the tcpdump ? quartz.newn.cam.ac.uk or 192.168.203.45 ?
> 
> In between, on yet another current box, tcpdumping on the 192.168 interface.
> The packet was routed through it using 2 ex(4)'s with h/w csum enabled.

Ok, so this is a packet that is about to be sent by a  h/w csuming interface.
It's OK not not have the correct checksum here.

-- 
Manuel Bouyer <bouyer@antioche.eu.org>
     NetBSD: 26 ans d'experience feront toujours la difference
--