From owner-freebsd-net@freebsd.org Mon Apr 16 08:28:12 2018 Return-Path: Delivered-To: freebsd-net@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 83D93F952F6 for ; Mon, 16 Apr 2018 08:28:12 +0000 (UTC) (envelope-from tom@erg.abdn.ac.uk) Received: from pegasus.erg.abdn.ac.uk (pegasus.erg.abdn.ac.uk [IPv6:2001:630:241:204::f0f0]) by mx1.freebsd.org (Postfix) with ESMTP id 1E9E382FFA for ; Mon, 16 Apr 2018 08:28:11 +0000 (UTC) (envelope-from tom@erg.abdn.ac.uk) Received: from auth1-smtp.messagingengine.com (auth1-smtp.messagingengine.com [66.111.4.227]) by pegasus.erg.abdn.ac.uk (Postfix) with ESMTPSA id 410161B00091; Mon, 16 Apr 2018 09:28:10 +0100 (BST) Received: from compute7.internal (compute7.nyi.internal [10.202.2.47]) by mailauth.nyi.internal (Postfix) with ESMTP id 53DAC21CD1; Mon, 16 Apr 2018 04:28:07 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute7.internal (MEProxy); Mon, 16 Apr 2018 04:28:07 -0400 X-ME-Sender: Received: from tom-desk.erg.abdn.ac.uk (tom-desk.erg.abdn.ac.uk [139.133.204.4]) by mail.messagingengine.com (Postfix) with ESMTPA id 9C7FCE4122; Mon, 16 Apr 2018 04:28:06 -0400 (EDT) Date: Mon, 16 Apr 2018 09:27:37 +0100 From: Tom Jones To: Nick Wolff Cc: freebsd-net@freebsd.org Subject: Re: QOS/TOS in carp/freebsd in general Message-ID: <20180416082736.GB48822@tom-desk.erg.abdn.ac.uk> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.2 (2017-12-15) X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 16 Apr 2018 08:28:12 -0000 On Sun, Apr 15, 2018 at 04:30:45PM -0400, Nick Wolff wrote: > Hi, > > I currently have a review in to make carp use dscp values on outgoing > packets. This will make it easier to preform QOS on modern switches as we > have been able to drive carp insane on 10g links while throwing storage > traffic at it.On an interesting side note apparently after 64k mac address > moves for a single mac address in the cam table arista 7050t seems to with > out warning give up and stop moving address but leaves it in the table > where ever it last was. > > I was originally going to just toggle between cs7 and the old TOS low delay > setting. But it was requested that I just make it a settable Integer value. > In this case I'm planning to do 0-63 to match dscp with a default of 54 > (CS7) (Network Control) but you could still set the old value by setting > the sysctl to 4. Anything larger then 64 would be truncated as two shifts > are needed to align with the field leading. > > Does anybody do anything anywhere with the old TOS values like low delay in > there networking infrastructure? Should this be updated in other places in > kernel and userland? It's been 20 years since TOS was deprecated and > replaced with DSCP. > > Any other comments or thought are always welcome. I cannot speak to network stacks, but we have performed some large scale DSCP measurements of the Internet and found TOS semantics still in use. You might want to look up: Exploring DSCP modification pathologies in mobile edge networks: IEEE/IFIP Workshop on Mobile Network Measurement I think there is more work in line to be published based on similar measurement campaigns. > References: > > Open Review - https://reviews.freebsd.org/D14536 > General DSCP reference - https://www.tucny.com/Home/dscp-tos > > > Thanks, > > Nick "darkfiberiru" Wolff > _______________________________________________ > freebsd-net@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" -- - [tj]