From owner-freebsd-net@FreeBSD.ORG Tue Jul 1 01:00:33 2008 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 E7DC1106567C for ; Tue, 1 Jul 2008 01:00:33 +0000 (UTC) (envelope-from if@xip.at) Received: from chile.gbit.at (ns1.xip.at [193.239.188.99]) by mx1.freebsd.org (Postfix) with ESMTP id 1A5778FC0A for ; Tue, 1 Jul 2008 01:00:32 +0000 (UTC) (envelope-from if@xip.at) Received: (qmail 3649 invoked from network); 1 Jul 2008 03:00:31 +0200 Received: from unknown (HELO filebunker.xip.at) (86.59.10.180) by chile.gbit.at with (DHE-RSA-AES256-SHA encrypted) SMTP; 1 Jul 2008 03:00:31 +0200 Date: Tue, 1 Jul 2008 03:00:31 +0200 (CEST) From: Ingo Flaschberger To: "Wilkinson, Alex" In-Reply-To: <20080701004346.GA3898@stlux503.dsto.defence.gov.au> Message-ID: References: <4867420D.7090406@gtcomm.net> <200806301944.m5UJifJD081781@lava.sentex.ca> <20080701004346.GA3898@stlux503.dsto.defence.gov.au> User-Agent: Alpine 1.10 (LFD 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: freebsd-net@freebsd.org Subject: Re: Freebsd IP Forwarding performance (question, and some info) [7-stable, current, em, smp] 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, 01 Jul 2008 01:00:34 -0000 Dear Alex, > >OK, I setup 2 boxes on either end of a RELENG_7 box from about May > >7th just now, to see with 2 boxes blasting across it how it would > >work. *However*, this is with no firewall loaded and, I must enable > >ip fast forwarding. Without that enabled, the box just falls over. > > What is "ip fast forwarding" ? instead of copying the while ip packet into system memory, only the ip header is copyied and then in a "fast" path determined if it could be fast forwarded. if possible, a ned header is created at the other network-cards-buffer and the ip-data is copied from network-card-buffer to network-card-buffer directly. Kind regards, Ingo Flaschberger