From owner-freebsd-net@FreeBSD.ORG Tue Aug 4 07:39:41 2009 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 5D0EA106566C for ; Tue, 4 Aug 2009 07:39:41 +0000 (UTC) (envelope-from bms@incunabulum.net) Received: from out1.smtp.messagingengine.com (out1.smtp.messagingengine.com [66.111.4.25]) by mx1.freebsd.org (Postfix) with ESMTP id 319918FC12 for ; Tue, 4 Aug 2009 07:39:40 +0000 (UTC) (envelope-from bms@incunabulum.net) Received: from compute1.internal (compute1.internal [10.202.2.41]) by out1.messagingengine.com (Postfix) with ESMTP id 7EE5D3AF765; Tue, 4 Aug 2009 03:39:40 -0400 (EDT) Received: from heartbeat1.messagingengine.com ([10.202.2.160]) by compute1.internal (MEProxy); Tue, 04 Aug 2009 03:39:41 -0400 X-Sasl-enc: BRMLY9ps+ijOhWBoafvrqDQjGRWpoDoHfie2gSlQ7EpH 1249371562 Received: from [192.168.123.18] (82-35-112-254.cable.ubr07.dals.blueyonder.co.uk [82.35.112.254]) by mail.messagingengine.com (Postfix) with ESMTPSA id 8E69E2D8A2; Tue, 4 Aug 2009 03:39:22 -0400 (EDT) Message-ID: <4A77E5B9.3060902@incunabulum.net> Date: Tue, 04 Aug 2009 08:39:37 +0100 From: Bruce Simpson User-Agent: Thunderbird 2.0.0.22 (Windows/20090605) MIME-Version: 1.0 To: "Brian A. Seklecki" References: <1249325867.19746.9.camel@soundwave.ws.pitbpa0.priv.collaborativefusion.com> In-Reply-To: <1249325867.19746.9.camel@soundwave.ws.pitbpa0.priv.collaborativefusion.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-net@freebsd.org, Bill Moran Subject: Re: net.inet.tcp.keepidle and friends X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 04 Aug 2009 07:39:41 -0000 Brian A. Seklecki wrote: > All: > > The description on this sysctl was just recently added in -CURRENT. It > was missing during all of RELENG_6 and RELENG_7? Do we not trust it > entirely, ergo the two hour initial threshold and lack of documentation? > I believe this has just been down to a lack of free time. I keep a copy of TII vol 2 around just in case I ever have to hack TCP; most of the time, it's a doorstop (all the code in almost every chapter of that book has significantly changed). > ... > fbsdhead$ sysctl -d net.inet.tcp.keepidle > net.inet.tcp.keepidle: time before keepalive probes > begin keepalive probe is sent > This is orthogonal, but: When responding to a bug report at $DAYJOB, I eyeballed the SYN-SENT timer code a week ago Sunday, and it looked to me like this knob was also controlling that TCP timer. However, correct me if I'm wrong: in RELENG_7 at least, it looked to me as though unacknowledged initial SYNs are not going to be retransmitted for an active TCP open due to connect() by FreeBSD, which looks like a regression. Is this really the case? The bug report in question was about a component wrapper for TCP sockets, which can't provide an API guarantee about TCP socket behaviour; it is implementation defined behaviour, and in this case, FreeBSD's TCP is the implementation.