Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 10 Jun 2002 04:05:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 10 Jun 2002 04:05:13 -0400 Received: from mail.zmailer.org ([62.240.94.4]:19603 "EHLO mail.zmailer.org") by vger.kernel.org with ESMTP id ; Mon, 10 Jun 2002 04:05:13 -0400 Date: Mon, 10 Jun 2002 11:05:13 +0300 From: Matti Aarnio To: Robert PipCA Cc: vortex@scyld.com, linux-kernel@vger.kernel.org Subject: Re: MTU discovery Message-ID: <20020610110513.I18899@mea-ext.zmailer.org> In-Reply-To: <20020610074507.69402.qmail@web21301.mail.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 10, 2002 at 12:45:07AM -0700, Robert PipCA wrote: > Hi, > I'm working on a project that require knowing the max MTU size > supported by the 3Com PCI 3c905C (Boomerang). > The datasheet provided by 3Com does not mention it, and I already > did the usual google search, but didn't find it neither. > Does anyone knows a "generic way" of knowing this (or chip-specific)? Oh, it is mentioned there, although not with that name. The Ethernet Standard (IEEE 802.3) specifies that the frame size shall be 1500 octets. That is the NORMAL CASE max MTU value for all ethernet devices. Some devices do, however, support reception (and transmit) of what is called "jumbograms". With boomerang you can set a register to contain the limit value. Alternatively with boomerang, and its predecessors, you can set a bit to accept extra-large frames. I recall the ultimate limit is in order of 4kB. > Thanks in advance. > --Robert /Matti Aarnio - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/