From owner-freebsd-hackers Sun Feb 21 16:12:19 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from obie.softweyr.com (unknown [204.68.178.33]) by hub.freebsd.org (Postfix) with ESMTP id 027F311886 for ; Sun, 21 Feb 1999 16:12:15 -0800 (PST) (envelope-from wes@softweyr.com) Received: from softweyr.com (zaphod.softweyr.com [204.68.178.35]) by obie.softweyr.com (8.8.8/8.8.8) with ESMTP id RAA09841; Sun, 21 Feb 1999 17:11:43 -0700 (MST) (envelope-from wes@softweyr.com) Message-ID: <36D0A0BE.3A725943@softweyr.com> Date: Sun, 21 Feb 1999 17:11:42 -0700 From: Wes Peters Organization: Softweyr llc X-Mailer: Mozilla 4.5 [en] (X11; U; FreeBSD 3.0-RELEASE i386) X-Accept-Language: en MIME-Version: 1.0 To: dg@root.com Cc: Luigi Rizzo , wpaul@skynet.ctr.columbia.edu, hackers@FreeBSD.ORG Subject: Re: How to handle jumbo etherney frames References: <199902211235.EAA12927@implode.root.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG David Greenman wrote: > > >> The jumbo frames are only useful if you also have VLAN support, which we > >> don't have currently. We also need support for large mbuf clusters; this > > > >hmmm i don't get this -- why is this related to VLAN ? > > Because most ethernets consist of a mix of hosts that don't have jumbo > frame capability. If you use jumbo frames without VLANs, then ALL hosts must > support jumbo frames This requires switching (or routing) between the hosts that do and do not support jumbo frames, but probably doesn't require VLAN tagging. You need to have all hosts on a physical segment support jumbo frames in order to run jumbo frames on that segment. > (and I think would also have to be gigabit ethernet > connected since jumbo frames weren't supported in 802.3...although I'm > assuming that the gigabit spec allows for jumbo frames, which may be a > bad assumption on my part). I think the jumbo frame specification is being added to the spec, but haven't read it yet. I will be in the next few weeks, though. Ugh. Supporting jumbo frames is an upcoming project for me. I'm watching this thread with great interest, as having support for jumbos in FreeBSD would make testing much simpler for me. It would also be nice to know that my implementation works with at least one other existing one before throwing it over the wall to testing. -- "Where am I, and what am I doing in this handbasket?" Wes Peters Softweyr LLC http://www.softweyr.com/~softweyr wes@softweyr.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message