From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 10 Aug 2001 14:46:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 10 Aug 2001 14:46:37 -0400 Received: from zero.aec.at ([195.3.98.22]:59402 "HELO zero.aec.at") by vger.kernel.org with SMTP id ; Fri, 10 Aug 2001 14:46:22 -0400 To: subba9@home.com (Subba Rao) cc: linux-kernel@vger.kernel.org Subject: Re: Half Duplex and Zero Copy IP In-Reply-To: <20010810095313.A6219@home.com> From: Andi Kleen Date: 10 Aug 2001 20:46:31 +0200 In-Reply-To: subba9@home.com's message of "Fri, 10 Aug 2001 13:53:56 +0000 (UTC)" Message-ID: User-Agent: Gnus/5.0700000000000003 (Pterodactyl Gnus v0.83) Emacs/20.2 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org In article <20010810095313.A6219@home.com>, subba9@home.com (Subba Rao) writes: > Hello, > I have 2 3Com NICs on my system. They are 3c905C Tornado PCI cards. > The drivers are compiled into the kernel (Slackware 8.0 with kernel 2.4.7). > One of the interfaces will be used as a sniffer interface (without IP address) > and a very high traffic pipes. I do not wish to loose any packets coming to this > interface. Is it better if I initialize the interface in HALF DUPLEX mode? If yes, > how do I set the card to HALF DUPLEX mode? How can I find out the HW (NIC) settings > on the system? Half duplex mode will only make your line slower, it has no benefit. > Another question about 3Com NICs, do they perform zero-copy IP? I read that > the performance improves a lot WITHOUT zero-copy IP. The sniffer zero copy implementation as implemented in some libpcaps does not depend on any special NIC support; it should work with any. -Andi