From owner-freebsd-net@FreeBSD.ORG Sat Sep 15 18:12:42 2007 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 91BEE16A418 for ; Sat, 15 Sep 2007 18:12:42 +0000 (UTC) (envelope-from julian@elischer.org) Received: from outT.internet-mail-service.net (outT.internet-mail-service.net [216.240.47.243]) by mx1.freebsd.org (Postfix) with ESMTP id 6371B13C45A for ; Sat, 15 Sep 2007 18:12:42 +0000 (UTC) (envelope-from julian@elischer.org) Received: from mx0.idiom.com (HELO idiom.com) (216.240.32.160) by out.internet-mail-service.net (qpsmtpd/0.40) with ESMTP; Sat, 15 Sep 2007 11:12:41 -0700 X-Client-Authorized: MaGic Cook1e X-Client-Authorized: MaGic Cook1e Received: from julian-mac.elischer.org (home.elischer.org [216.240.48.38]) by idiom.com (Postfix) with ESMTP id E68151263BE; Sat, 15 Sep 2007 11:12:40 -0700 (PDT) Message-ID: <46EC2098.2000908@elischer.org> Date: Sat, 15 Sep 2007 11:12:40 -0700 From: Julian Elischer User-Agent: Thunderbird 2.0.0.6 (Macintosh/20070728) MIME-Version: 1.0 To: Randy Bush References: <46EAE78D.8060108@elischer.org> <46EC0E75.5070307@psg.com> <46EC1575.4070401@elischer.org> <46EC16DC.2010104@psg.com> In-Reply-To: <46EC16DC.2010104@psg.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: FreeBSD Net Subject: Re: BCE on FreeBSD and oversized packet acceptance. 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, 15 Sep 2007 18:12:42 -0000 Randy Bush wrote: >>>> what size is the actual maximal sized jumbo packet we will ever see? >>> some transpac science community folk, who care more about speed trials >>> with big data sets than they do about over-stretching the ethernet crc, >>> use 9k jumbo frames. >> well that's the standard but the highest I've seen mentioned as a normal >> size is I think 9220 bytes. > > i suggest being careful with the word "standard." ieee, which controls > the ethernet spec, has refused to standardize anything above 1500 on the > grounds that it would over-stretch the crc. > true, (I was surprised to not see 9k packets in the standard (though old) that I have. (I guess now I'm in Cisco I could get to a newer one). but practicality suggests that we spport what the customer is doing. > randy