Patrick McHardy wrote: > Herbert Xu wrote: [] >> Since you're certain that this is being seen on the wire, one >> possibility is that we've got a bug somewhere that's zeroing >> skb->ip_summed on a packet with a partial checksum. >> >> One potential spot where this could happen is netfilter. >> Patrick, do you know of any recent changes (this is happening >> with 2.6.19) that might cause this? > > The incremental HW checksum update stuff went in 2.6.19, so thats > a prime suspect. Can't see where this could be happening though. > > Michael, how exactly is netfilter involved in your setup?
I think it doesn't involved. The captures I did were done on a router box, which indeed has some netfilter stuff. But: 1) the capture has been done on an interface directly connected to the segment where the "testing" machine is located (not on the "external" interface) 2) the "testing" machine itself does not have any netfilter modules loaded 3) the packets looks exactly the same in at least 3 places (modulo the TTL values): on the sending machine, on the router (on the interface connected to the sending machine - in those 2 places, the TTL is the same), and at the receiving side, which is 20+ hops away. 4) I tried another machine today (upgraded from 2.6.17 to 2.6.19) - stand-alone, without any netfilter modules loaded (but it's under quite.. some load - see http://j.ns.dsbl.org/nsg/ -- with this load it'll die right after iptables module loading, it's a 600MHz Celeron box replying to 15000 DNS packets every secound) - it started showing the same behavior. /mjt - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
