From mboxrd@z Thu Jan 1 00:00:00 1970 From: "James Nichols" Subject: Re: After many hours all outbound connections get stuck in SYN_SENT Date: Wed, 19 Dec 2007 13:12:41 -0500 Message-ID: <83a51e120712191012r64783b7dk56cc4fbcbdd5685c@mail.gmail.com> References: <83a51e120712141239u52d2dd68p1b6ee7ed08f2cecf@mail.gmail.com> <83a51e120712181021p4c4c2a13g8820271f1e00361b@mail.gmail.com> <4768123A.7040603@cosmosbay.com> <83a51e120712181144l65633b32r72cc369f9d012f47@mail.gmail.com> <47682F8C.20205@cosmosbay.com> <83a51e120712190853q33d9c7c1t4a46380665b7538b@mail.gmail.com> <47694FCC.1020507@cosmosbay.com> <83a51e120712190943m3bf0e2e4v2ea6b660142e9a5a@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "Eric Dumazet" , linux-kernel@vger.kernel.org, "Linux Netdev List" To: "Jan Engelhardt" Return-path: Received: from fg-out-1718.google.com ([72.14.220.158]:1635 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752518AbXLSSMm (ORCPT ); Wed, 19 Dec 2007 13:12:42 -0500 Received: by fg-out-1718.google.com with SMTP id e21so504995fga.17 for ; Wed, 19 Dec 2007 10:12:41 -0800 (PST) In-Reply-To: Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: > The router could be sooo crappy that it drops all packets from > TCP streams that have SACK enabled and the client has opened > 200+ SACK connections previously... something like that? I don't know, maybe. My router is a fairly new model Cisco and is pretty major (i.e. pretty expensive), so it's not just a total piece of crap. Plus, I never restart it when I see these issues. I just turn tcp_sack off, the problem goes away, and I'm able to renable tcp_sack a few hours later and it works fine until many hours later when I see the SYN_SENT problem again.