From owner-freebsd-net@FreeBSD.ORG Thu May 27 08:05:25 2004 Return-Path: <owner-freebsd-net@FreeBSD.ORG> Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id A213F16A4CF for <net@freebsd.org>; Thu, 27 May 2004 08:05:25 -0700 (PDT) Received: from odin.ac.hmc.edu (Odin.AC.HMC.Edu [134.173.32.75]) by mx1.FreeBSD.org (Postfix) with ESMTP id 563F943D49 for <net@freebsd.org>; Thu, 27 May 2004 08:05:17 -0700 (PDT) (envelope-from brdavis@odin.ac.hmc.edu) Received: from odin.ac.hmc.edu (IDENT:brdavis@localhost.localdomain [127.0.0.1]) by odin.ac.hmc.edu (8.12.10/8.12.10) with ESMTP id i4RF2SSK032075; Thu, 27 May 2004 08:02:28 -0700 Received: (from brdavis@localhost) by odin.ac.hmc.edu (8.12.10/8.12.3/Submit) id i4RF2S3n032074; Thu, 27 May 2004 08:02:28 -0700 Date: Thu, 27 May 2004 08:02:28 -0700 From: Brooks Davis <brooks@one-eyed-alien.net> To: Yar Tikhiy <yar@comp.chem.msu.su> Message-ID: <20040527150228.GB30789@Odin.AC.HMC.Edu> References: <200405251449.i4PEnkIa098672@repoman.freebsd.org> <20040525164251.GA3245@ip.net.ua> <20040525173458.GA18554@comp.chem.msu.su> <20040525184757.GA5546@ip.net.ua> <20040526032055.GA42697@comp.chem.msu.su> <20040526064152.GD24738@cell.sick.ru> <20040527141055.GA32704@comp.chem.msu.su> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="xgyAXRrhYN0wYx8y" Content-Disposition: inline In-Reply-To: <20040527141055.GA32704@comp.chem.msu.su> User-Agent: Mutt/1.5.4i cc: net@freebsd.org Subject: Re: VLAN_MTU (was Re: cvs commit: src/sys/dev/fxp if_fxp.c if_fxpvar.h) X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Networking and TCP/IP with FreeBSD <freebsd-net.freebsd.org> List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>, <mailto:freebsd-net-request@freebsd.org?subject=unsubscribe> List-Archive: <http://lists.freebsd.org/pipermail/freebsd-net> List-Post: <mailto:freebsd-net@freebsd.org> List-Help: <mailto:freebsd-net-request@freebsd.org?subject=help> List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>, <mailto:freebsd-net-request@freebsd.org?subject=subscribe> X-List-Received-Date: Thu, 27 May 2004 15:05:25 -0000 --xgyAXRrhYN0wYx8y Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, May 27, 2004 at 06:10:55PM +0400, Yar Tikhiy wrote: > [moving the discussion from the cvs lists to -net] >=20 > On Wed, May 26, 2004 at 10:41:52AM +0400, Gleb Smirnoff wrote: > >=20 > > Y> ng_vlan(4) could send a control command to ng_ether(4) instructing > > Y> the latter to increment the VLAN counter on the Ethernet interface > > Y> and toggle VLAN_MTU on if the counter value became equal to 1. > >=20 > > Two comments: > >=20 > > 1) Just note that it should increment VLAN counter on creating of > > any new VLAN hook. > > 2) There may be some itermediate nodes between ng_ether and ng_vlan, > > e.g. ng_tee(4), ng_etf(4), any custom traffic shaping or accounting > > node. > >=20 > > Two deal with second issue some new mechanism should be introduced in n= etgraph, > > e.g. "broadcast" messages, which go down a hook spreading across all no= des, > > and only nodes with appropriate cookie will see this message delivered. > >=20 > > Y> Another way I see is to drop automatic fiddling with VLAN_MTU in > > Y> the first place and implement an option for ifconfig(8) so that a > > Y> user/admin can control the capability WRT a particular case, e.g., > > Y> disable it if a NIC displays erroneous behaviour in long frame mode. > >=20 > > From my point of view this is a good idea. >=20 > The longer I've been thinking of the issue, the more I'm inclined > to take the latter path. I believe that it would conform to the > good tradition of Unix to offer a user as much control as possible > and avoid doing "automagic" tricks behind user's back. >=20 > Therefore I'd like to ask the community: Would anybody mind if > vlan(4) gave up playing with VLAN_MTU on parent interfaces > while a new option to ifconfig(8), say `vlanmtu', was introduced > so that a user could control the feature manually? This seems OK as long as you enabled VLAN_MTU by default as I see you have just done with fxp. -- Brooks --=20 Any statement of the form "X is the one, true Y" is FALSE. PGP fingerprint 655D 519C 26A7 82E7 2529 9BF0 5D8E 8BE9 F238 1AD4 --xgyAXRrhYN0wYx8y Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (GNU/Linux) iD8DBQFAtgMDXY6L6fI4GtQRAtE4AJ9FIZ3b9KRu6MVMUxClIUSz2QIYRACfRx/B HEkbgd08BuCxTmMMZWjjRhg= =VNbK -----END PGP SIGNATURE----- --xgyAXRrhYN0wYx8y--