From owner-freebsd-net@freebsd.org Fri Dec 28 10:15:54 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 6B47A1433D4F for ; Fri, 28 Dec 2018 10:15:54 +0000 (UTC) (envelope-from prvs=8938e5aed=youssef.ghorbal@pasteur.fr) Received: from mx0.pasteur.fr (mx0.pasteur.fr [157.99.45.50]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "Cisco Appliance Demo Certificate", Issuer "Cisco Appliance Demo Certificate" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 0770C83D82 for ; Fri, 28 Dec 2018 10:15:52 +0000 (UTC) (envelope-from prvs=8938e5aed=youssef.ghorbal@pasteur.fr) Received-SPF: None (mx0.pasteur.fr: no sender authenticity information available from domain of youssef.ghorbal@pasteur.fr) identity=pra; client-ip=157.99.211.32; receiver=mx0.pasteur.fr; envelope-from="youssef.ghorbal@pasteur.fr"; x-sender="youssef.ghorbal@pasteur.fr"; x-conformance=sidf_compatible Received-SPF: None (mx0.pasteur.fr: no sender authenticity information available from domain of youssef.ghorbal@pasteur.fr) identity=mailfrom; client-ip=157.99.211.32; receiver=mx0.pasteur.fr; envelope-from="youssef.ghorbal@pasteur.fr"; x-sender="youssef.ghorbal@pasteur.fr"; x-conformance=sidf_compatible Received-SPF: None (mx0.pasteur.fr: no sender authenticity information available from domain of postmaster@EXCHANGE02.corp.pasteur.fr) identity=helo; client-ip=157.99.211.32; receiver=mx0.pasteur.fr; envelope-from="youssef.ghorbal@pasteur.fr"; x-sender="postmaster@EXCHANGE02.corp.pasteur.fr"; x-conformance=sidf_compatible X-IronPort-AV: E=Sophos;i="5.56,409,1539640800"; d="scan'208,217";a="18852799" Received: from exchange02.corp.pasteur.fr ([157.99.211.32]) by mx0.pasteur.fr with ESMTP/TLS/AES256-GCM-SHA384; 28 Dec 2018 11:14:41 +0100 Received: from EXCHANGE03.corp.pasteur.fr (2002:9d63:d321::9d63:d321) by EXCHANGE02.corp.pasteur.fr (2002:9d63:d320::9d63:d320) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1415.2; Fri, 28 Dec 2018 11:14:40 +0100 Received: from EXCHANGE03.corp.pasteur.fr ([fe80::cce4:ae6a:ec0a:16c9]) by EXCHANGE03.corp.pasteur.fr ([fe80::cce4:ae6a:ec0a:16c9%18]) with mapi id 15.01.1415.002; Fri, 28 Dec 2018 11:14:58 +0100 From: "Youssef GHORBAL" To: "Muenz, Michael" CC: "freebsd-net@freebsd.org" Subject: Re: DUP ACKs sent with no reason Thread-Topic: DUP ACKs sent with no reason Thread-Index: AQHUnhKUMBj1UvaeXkCuQysZDc8SsaWToqcAgAA8uIA= Date: Fri, 28 Dec 2018 10:14:58 +0000 Message-ID: <0D994B53-FB3D-450C-8276-82649B6289FE@pasteur.fr> References: <74db0aae-3f93-aaa5-7241-8043ba0254bf@spam-fetish.org> In-Reply-To: <74db0aae-3f93-aaa5-7241-8043ba0254bf@spam-fetish.org> Accept-Language: en-US, fr-FR Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [157.99.101.115] MIME-Version: 1.0 X-Rspamd-Queue-Id: 0770C83D82 X-Spamd-Bar: +++ Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [3.63 / 15.00]; TO_DN_EQ_ADDR_SOME(0.00)[]; HAS_XOIP(0.00)[]; TO_DN_SOME(0.00)[]; ENVFROM_PRVS(0.00)[]; RCVD_COUNT_THREE(0.00)[4]; MX_GOOD(-0.01)[cached: mx0.pasteur.fr]; RCPT_COUNT_TWO(0.00)[2]; FORGED_SENDER(0.00)[youssef.ghorbal@pasteur.fr,prvs=8938e5aed=youssef.ghorbal@pasteur.fr]; IP_SCORE(-0.00)[country: FR(-0.02)]; R_DKIM_NA(0.00)[]; ASN(0.00)[asn:29110, ipnet:157.99.0.0/16, country:FR]; MIME_TRACE(0.00)[0:+,1:+]; FROM_NEQ_ENVFROM(0.00)[youssef.ghorbal@pasteur.fr,prvs=8938e5aed=youssef.ghorbal@pasteur.fr]; ARC_NA(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; FROM_HAS_DN(0.00)[]; NEURAL_SPAM_SHORT(0.38)[0.380,0]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; DMARC_NA(0.00)[pasteur.fr]; FORGED_SENDER_VERP_SRS(0.00)[]; AUTH_NA(1.00)[]; NEURAL_SPAM_MEDIUM(0.84)[0.838,0]; TO_MATCH_ENVRCPT_SOME(0.00)[]; NEURAL_SPAM_LONG(0.53)[0.526,0]; RCVD_IN_DNSWL_NONE(0.00)[50.45.99.157.list.dnswl.org : 127.0.10.0]; RCVD_TLS_LAST(0.00)[]; R_SPF_NA(0.00)[]; FROM_NAME_EXCESS_SPACE(1.00)[] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.29 X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 28 Dec 2018 10:15:54 -0000 On 28 Dec 2018, at 07:37, Muenz, Michael > wrote: Am 27.12.2018 um 19:32 schrieb Youssef GHORBAL: What can explain those DUP ACKs sent by the FreeBSD host? (DUP ACKs sent by= the client are "normal" in a way to report missing packet loss and carry S= elective ACKs, but those sent by the BSD stack are hard to explain) How can I push the investigation further ? Hi, I had similar phenomenons with DUP ACKs, lost packets and also duplicate IC= MP replies when using Intel X710 cards. Did you test exchanging hardware and trying Linux-only and/or BSD-only iper= f to look for a difference? Thanks Michael. I've tested what you suggested : - iperf3 on Linux on both sides is working fine. (but It's not the same ser= ver with Linux on it, it's another box so I'm not sure it's a relevant test= ) - iperf3 on FreeBSD on both sides exhebits the issue. (the client is not th= e same one as the Linux box in my initial tests, the server is) =3D> I'm tempting to think that it's the FreeBSD that is the issue here. I've also tested with other cards, on the FreeBSD host I have mellanox NICs= and I have the same issue. There is also something I forget to mention in my initial email. On the BSD= host the network is configured with a lagg enslaving two cards. I've had weird issues in the past when a single TCP session was scattred ac= ross the two NICs of a lagg : https://lists.freebsd.org/pipermail/freebsd-net/2017-June/048291.html This time I've ensured (using tcpdump on both cards of the lagg) that all t= cp segments of the dialogue was actually using only one NIC. Is there any known dtrace magic to track which part of the code is sending = those ACKs ? Youssef Ghorbal