From owner-freebsd-net@FreeBSD.ORG Sat Aug 20 17:50:30 2005 Return-Path: X-Original-To: freebsd-net@freebsd.org Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 37D5E16A41F; Sat, 20 Aug 2005 17:50:30 +0000 (GMT) (envelope-from chvogt@tm.uka.de) Received: from iramx2.ira.uni-karlsruhe.de (iramx2.ira.uni-karlsruhe.de [141.3.10.81]) by mx1.FreeBSD.org (Postfix) with ESMTP id 85FBD43D48; Sat, 20 Aug 2005 17:50:29 +0000 (GMT) (envelope-from chvogt@tm.uka.de) Received: from irams1.ira.uni-karlsruhe.de ([141.3.10.5]) by iramx2.ira.uni-karlsruhe.de with esmtps id 1E6XU9-0004XO-Fo; Sat, 20 Aug 2005 19:50:28 +0200 Received: from i72archimedes.tm.uni-karlsruhe.de ([141.3.71.83]) by irams1.ira.uni-karlsruhe.de with esmtpsa id 1E6XU8-0002Lp-8j; Sat, 20 Aug 2005 19:50:24 +0200 Message-ID: <43076D5A.5070703@tm.uka.de> Date: Sat, 20 Aug 2005 19:50:18 +0200 From: Christian Vogt User-Agent: Mozilla/5.0 (X11; U; Linux i686; de-DE; rv:1.7.10) Gecko/20050716 Thunderbird/1.0.6 Mnenhy/0.7.2.0 X-Accept-Language: de-DE, de, en-us, en MIME-Version: 1.0 To: Andre Oppermann References: <4307628A.9050102@tm.uka.de> <43076895.7C238E6E@freebsd.org> In-Reply-To: <43076895.7C238E6E@freebsd.org> X-Enigmail-Version: 0.90.0.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig04BF8EF4F8D0F70D4DBDF92D" X-Spam-Score: -10.6 (----------) X-Spam-Status: No Cc: freebsd-net@freebsd.org, TM-RO2 Subject: Re: Deactivate TCP Hostcache? 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: Sat, 20 Aug 2005 17:50:30 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig04BF8EF4F8D0F70D4DBDF92D Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Hi Andre, thanks for the info. What I did is this: I changed the TCP_HOSTCACHE_PRUNE constant from 5 minutes to 5 seconds. After one experimentation run, my scripts call 'sysctl net.inet.tcp.hostcache.purge=1 && sleep 5'. This guarantees that there is no remaining info in the TCP hostcache when the next experimentation run takes off. Bye, - Christian -- Christian Vogt, Institute of Telematics, University of Karlsruhe www.tm.uka.de/~chvogt/pubkey/ Andre Oppermann wrote: > Christian Vogt wrote: > >>Hi everybody, >> >>is there a way to deactivate the TCP hostcache? >> >>I could modify the kernel, but probably there is a more convenient way >>to do this. > > > No, there is no other way. > > >>The reason I want to deactivate the hostcache is because I am doing >>experiments and later measurements should not be different than earlier >>ones due to cached information. > > > Comment out the tcp_hc_update() call on line 737 in netinet/tcp_subr.c > and it won't cache metrics anymore. The discovered path MTU is still > stored though. > --------------enig04BF8EF4F8D0F70D4DBDF92D Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.0 (GNU/Linux) iD8DBQFDB21fwstEk8gl2rURAirqAKDVGf56jKQqdlVLJSOLYDVpVbiKhwCeN5m5 5OkeOJXLiuatvEQHUd7NHhw= =CPP4 -----END PGP SIGNATURE----- --------------enig04BF8EF4F8D0F70D4DBDF92D--