On 19/08/13 - 07:35:09, Phil Oester wrote: > On Mon, Aug 19, 2013 at 06:58:05AM -0700, Eric Dumazet wrote: > > Yeah, but here, this is conntrack who is blocking the thing. > > > > TCP receiver has no chance to 'fix' it. > > > > See conntrack is one of those buggy middle box as well. > > > > So if you want to properly handle this mess, you'll also have to fix > > conntrack. > > Better to fix the box which is randomizing the acks and ignoring > the SACKs. Usually these are older Cisco PIX/ASA devices which just > need a code upgrade. I agree, the problem are these horrid middleboxes... Unfortunately, they will hardly go away in the near futur. Rather the opposite is the case. If you have a public server running, I would be interested in the count of invalid SACK-blocks received (netstat -s | grep TCPSACKDiscard). This is an indication for such kind of middlebox between your server and the client, implying that these connections cannot benefit from TCP-FastRetransmission and each packet-loss will require an RTO to recover. Cheers, Christoph -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
