From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753500Ab2HaNZy (ORCPT ); Fri, 31 Aug 2012 09:25:54 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:33492 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752753Ab2HaNZx (ORCPT ); Fri, 31 Aug 2012 09:25:53 -0400 Subject: Re: [PATCH 1/1] tcp: Wrong timeout for SYN segments From: Eric Dumazet To: Alexander Bergmann Cc: davem@davemloft.net, hkjerry.chu@gmail.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20120831124831.GA23279@linlab.net> References: <1345724123.5904.756.camel@edumazet-glaptop> <20120824.134231.41073001349178209.davem@davemloft.net> <20120825084819.GD430@linlab.net> <201208281044.40057.carsten@wolffcarsten.de> <1346414260.2591.8.camel@edumazet-glaptop> <20120831124831.GA23279@linlab.net> Content-Type: text/plain; charset="UTF-8" Date: Fri, 31 Aug 2012 06:25:50 -0700 Message-ID: <1346419550.2591.12.camel@edumazet-glaptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2012-08-31 at 14:48 +0200, Alexander Bergmann wrote: > Hi Eric! > > I've also changed the Documentation file. As usual, comments are welcome! > > > Alex > > > From 848f34ce27f65401940ae98e0b2d395888d3986d Mon Sep 17 00:00:00 2001 > From: Alexander Bergmann > Date: Fri, 31 Aug 2012 14:31:00 +0200 > Subject: [PATCH 1/1] tcp: Increase timeout for SYN segments > > Commit 9ad7c049 changed the initRTO from 3secs to 1sec in accordance to > RFC6298 (former RFC2988bis). This reduced the time till the last SYN > retransmission packet gets sent from 93secs to 31secs. > > RFC1122 is stating that the retransmission should be done for at least 3 > minutes, but this seems to be quite high. > > "However, the values of R1 and R2 may be different for SYN > and data segments. In particular, R2 for a SYN segment MUST > be set large enough to provide retransmission of the segment > for at least 3 minutes. The application can close the > connection (i.e., give up on the open attempt) sooner, of > course." > > This patch increases the value of TCP_SYN_RETRIES to the value of 6, > providing a retransmission window of 63secs. > > The comments for SYN and SYNACK retries have also been updated to > describe the current settings. The same goes for the documentation file > "Documentation/networking/ip-sysctl.txt". > > Signed-off-by: Alexander Bergmann > --- Thanks for your patience and followup, this seems good to me ! Acked-by: Eric Dumazet