From owner-freebsd-stable@FreeBSD.ORG Wed Oct 24 13:48:38 2012 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 7021236D for ; Wed, 24 Oct 2012 13:48:38 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: from mail-pb0-f54.google.com (mail-pb0-f54.google.com [209.85.160.54]) by mx1.freebsd.org (Postfix) with ESMTP id 40BB88FC08 for ; Wed, 24 Oct 2012 13:48:38 +0000 (UTC) Received: by mail-pb0-f54.google.com with SMTP id rp8so1304495pbb.13 for ; Wed, 24 Oct 2012 06:48:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; bh=TOwvJT6GSJJL3qZX5aHCC60xmiJOjg90EKbZeOlaILQ=; b=Q+K8X7aMjLn3GiEC1ERS69gUefV7en/ZAW9qdTbs2iqnDcVuSsq6gFPCHCS/5GbNxK 0Odia/2TEa6s/QgHq2L2oxHEuNxggdbKqFSx6Ee30bNsBBJR7s1qBpEYfz54Vc9p4ja1 zIj03GOrHVldtaL6s8PLSlWSvkUjE689GlyC6aDj165HucpHDSmczDABeptS7P6pkFp2 txqFz69k6FLgQP42CtjkYfB8Y6VJ1u/7yXlkOg7ouCtSGtxzReaDUg1KHKx5w9V9KJRK Mgx0q8TShQ+616agsVDu4UWx5z3uzWUnGGhlRVIPsPZeyG6OUK062XCLcg3FSiBQX72B 9ghw== MIME-Version: 1.0 Received: by 10.66.74.65 with SMTP id r1mr44086968pav.75.1351086517535; Wed, 24 Oct 2012 06:48:37 -0700 (PDT) Sender: adrian.chadd@gmail.com Received: by 10.68.146.233 with HTTP; Wed, 24 Oct 2012 06:48:37 -0700 (PDT) In-Reply-To: <5087DFA1.7090001@omnilan.de> References: <5087DFA1.7090001@omnilan.de> Date: Wed, 24 Oct 2012 06:48:37 -0700 X-Google-Sender-Auth: rtHq_jKJ8E2EA8EN7HwSfTOfG2U Message-ID: Subject: Re: every 2nd echo-request malformed when ping -s >4067 From: Adrian Chadd To: Harald Schmalzbauer Content-Type: text/plain; charset=ISO-8859-1 Cc: FreeBSD Stable X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 24 Oct 2012 13:48:38 -0000 On 24 October 2012 05:31, Harald Schmalzbauer wrote: > Hello, > > while checking new mtu9k-setup, I discovered that ping has some odd > behaviour. > If I use payloadsize > 4067, every 2nd icmp-echo-request seems to be > malformed: Is this on -HEAD? > ping -s 4068 -D 10.5.49.65 > > 1st: 12:21:09.048447 IP 10.5.49.126 > 10.5.49.65: ICMP echo request, id > 46597, seq 0, length 4076 > 0x0000: 4500 1000 0f2d 4000 4001 a507 0a05 317e > > 2nd: 12:21:10.052891 IP 10.5.49.126 > 10.5.49.65: icmp > 0x0000: 4500 1000 0f2d 0040 4001 e4c7 0a05 317e > > 3rd: 12:21:11.062900 IP 10.5.49.126 > 10.5.49.65: ICMP echo request, id > 46597, seq 2, length 4076 > 0x0000: 4500 1000 0f2d 4000 4001 a507 0a05 317e > > 4th: 12:21:12.072915 IP 10.5.49.126 > 10.5.49.65: icmp > 0x0000: 4500 1000 0f2d 0040 4001 e4c7 0a05 317e > > 5th: 12:21:13.082900 IP 10.5.49.126 > 10.5.49.65: ICMP echo request, id > 46597, seq 4, length 4076 > 0x0000: 4500 1000 0f2d 4000 4001 a507 0a05 317e > > When payload is 4076, outgoing _every_ outgoing request begins with > 4500 xxxx xxxx 4000 4001, > while above we see every second request starting with > 4500 xxxx xxxx 0040 4001. > Does anybody know header composing off pat? Haven't seen these bits for > quiet some time... Glebius was recently in the networking stack in -HEAD, fiddling with how IP headers are treated. Maybe this is some corner case fallout from that? adrian