From owner-freebsd-net@freebsd.org Mon May 29 06:50:37 2017 Return-Path: Delivered-To: freebsd-net@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 786BECC23EF for ; Mon, 29 May 2017 06:50:37 +0000 (UTC) (envelope-from zbeeble@gmail.com) Received: from mail-wm0-x230.google.com (mail-wm0-x230.google.com [IPv6:2a00:1450:400c:c09::230]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id D0E301A47 for ; Mon, 29 May 2017 06:50:36 +0000 (UTC) (envelope-from zbeeble@gmail.com) Received: by mail-wm0-x230.google.com with SMTP id d127so45671682wmf.0 for ; Sun, 28 May 2017 23:50:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=GcF9uKY9YTMVGGSvAoShfONhXYuPMjJ5dC+D0ADuaOM=; b=WwXQqvcbG3UTWM7BQTM7ayKPTRuhNNIRdxMShRbDY3+H7FivM1ovly2k/IA1NfQsms q5Qt9d0JH+IZiQCY5b9ajmMCG7jzj7dX5qwvjDJMql56YRD7ASnGnnD9YQsg0pS8kaR/ LeVIiQq0t/ao4sfo9H06QzrMRjPsmQz30MYFuob0VJrZ/2FLILT13Od423AplrH5it+s LK8NufoGE9jT47T9gamR3Et/E+SVJkHibO+DPfkZFulnBVtQpTBfmAivAZp4GZC975xw A+Ebc+Dzm1euZH4otAK3+agPFRIPK3BzV3r0Mz9Ze8uAl0o0Jf4m3kiDsisyaTWbc344 COVg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=GcF9uKY9YTMVGGSvAoShfONhXYuPMjJ5dC+D0ADuaOM=; b=NaTFD/cuX5RCxKdNktvc1iuyrF7W2PZ+BoloieFArA74oPLVGcULQ/ic0BHFMXYLcw or5bxQJo7GbE+PVbJRy+D5g3KXsy++xd38EwTiPveziSVZWf9FCbi97OboLIoiJpvcZn 0haOmkwXwEFWFkcr9848FYk3JlTwMwwEdZlbzvRe9GybrHXG6Dis1xvNLUv6qV54XClK O8ugVcavWcIaXD1WD8P6aBkKjvUamL2Uz6z2BUJOtL7I8H1Qj0GJkjnhoTGsUWOUqc6e A+Jnz5rbBXYcEkJZ8MqGfVJrzTFu6WqiALA+htUNn1NpXf1f7EG6JsBEMtmLfJTnHr+D NDbQ== X-Gm-Message-State: AODbwcCsUgRfnCqaoILg6f/yzSD8qNbjAbMi/vL944Ez/oe0QrxQYsPO DHEp74jQmWN2GASzV7OKvLPn4gfdCg== X-Received: by 10.80.167.4 with SMTP id h4mr11698496edc.142.1496040635347; Sun, 28 May 2017 23:50:35 -0700 (PDT) MIME-Version: 1.0 Received: by 10.80.186.24 with HTTP; Sun, 28 May 2017 23:50:34 -0700 (PDT) From: Zaphod Beeblebrox Date: Mon, 29 May 2017 02:50:34 -0400 Message-ID: Subject: OCD window scaling behavior on local network. To: FreeBSD Net Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.23 X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.23 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, 29 May 2017 06:50:37 -0000 so... I have some really OCD window scaling behavior on a GigE local network. The protocol is BGP, this is one session recorded. Nearly every payload packet is answered by both an 'ACK' and a 2nd window scaling packet. I have examined the packet counters: no errors reported by the box or the managed switch. Also, TCP-MD5 is not in use, if that matters. [image: Inline image 1]