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.

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