From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bifrost.lang.hm (lang.hm [66.167.227.134]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id E4DB13B260; Fri, 20 May 2016 13:26:22 -0400 (EDT) Received: from asgard.lang.hm (asgard.lang.hm [10.0.0.100]) by bifrost.lang.hm (8.13.4/8.13.4/Debian-3) with ESMTP id u4KHQBfr030482; Fri, 20 May 2016 10:26:11 -0700 Date: Fri, 20 May 2016 10:26:11 -0700 (PDT) From: David Lang X-X-Sender: dlang@asgard.lang.hm To: Jonathan Morton cc: Rick Jones , cake@lists.bufferbloat.net, codel@lists.bufferbloat.net In-Reply-To: Message-ID: References: <22371476-B45C-4E81-93C0-D39A67639EA0@gmx.de> <991C8B50-192E-431A-819F-F1C5954FF64F@gmx.de> <4C5D0005-2CAA-4C90-BF0D-7177874872AC@gmail.com> <573F394B.5060009@hpe.com> <26FFB878-5E6B-47B8-8DFD-A8765421655F@gmail.com> <573F42DF.9010108@hpe.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: MULTIPART/MIXED; BOUNDARY="680960-1067122096-1463765171=:2282" Subject: Re: [Cake] [Codel] Proposing COBALT X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 20 May 2016 17:26:23 -0000 This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --680960-1067122096-1463765171=:2282 Content-Type: TEXT/PLAIN; charset=utf-8; format=flowed Content-Transfer-Encoding: 8BIT On Fri, 20 May 2016, Jonathan Morton wrote: >> On 20 May, 2016, at 20:01, Rick Jones wrote: >> >> But I haven't seen that EMSGSIZE happen with netperf UDP tests - could be though I've never run them in an environment which triggered PTMUD. > > It’s entirely possible that netperf and/or iperf3 are (ab)using the IP_MTU_DISCOVERY socket option mentioned. iperf3 defaults to a mss of 1200 bytes, well below the MTU David Lang --680960-1067122096-1463765171=:2282--