On Thu, Mar 17, 2005 at 07:14:28PM +0100, Manuel Bouyer wrote:
> On Thu, Mar 17, 2005 at 05:22:45PM +0000, Patrick Welche wrote:
> > Just a "me too".. Also on ex0, with h/w csumming enabled:
> > 
> > 17:16:13.805723 IP (tos 0x10, ttl  64, id 41336, offset 0, flags [DF], length: 52, bad cksum 0 (->f8f0)!) 131.111.204.180.65215 > 131.111.204.183.22: . [bad tcp cksum a071 (->38f)!] ack 2560 win 33580 <nop,nop,timestamp 4600 4600>
> > 
> > 
> > lots of packets with bad cksum..
> > 
> > However, with h/w checksums turned off, all OK according to tcpdump.
> > (Running current/i386 of yesterday)
> 
> I think this is to be expected when using hardware checksum: in this case,
> as the checksum will be computed by the adapter, the packet passed to BPF
> didn't have the checksum updated.

Good point..

Patrick