From owner-freebsd-net@freebsd.org Sun Jul 2 15:23:36 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 DB1DDDA7F44 for ; Sun, 2 Jul 2017 15:23:36 +0000 (UTC) (envelope-from eugen@grosbein.net) Received: from hz.grosbein.net (hz.grosbein.net [78.47.246.247]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "hz.grosbein.net", Issuer "hz.grosbein.net" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id DD2936E598 for ; Sun, 2 Jul 2017 15:23:35 +0000 (UTC) (envelope-from eugen@grosbein.net) Received: from eg.sd.rdtc.ru (root@eg.sd.rdtc.ru [62.231.161.221]) by hz.grosbein.net (8.15.2/8.15.2) with ESMTPS id v62FNQZr022524 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sun, 2 Jul 2017 17:23:26 +0200 (CEST) (envelope-from eugen@grosbein.net) X-Envelope-From: eugen@grosbein.net X-Envelope-To: herbert@mailbox.org Received: from [10.58.0.4] ([10.58.0.4]) by eg.sd.rdtc.ru (8.15.2/8.15.2) with ESMTPS id v62FNLDv059407 (version=TLSv1.2 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT); Sun, 2 Jul 2017 22:23:21 +0700 (+07) (envelope-from eugen@grosbein.net) Subject: Re: [Bug 220351] Path MTU discovery works only after resetting an internal interface MTU (mpd5, ng_nat, ipfw) To: "Herbert J. Skuhra" References: <87r2xzaw30.wl-herbert@mailbox.org> <87bmp3x7eu.wl-herbert@mailbox.org> <59590064.1040700@grosbein.net> <87a84myitf.wl-herbert@mailbox.org> Cc: freebsd-net@FreeBSD.org From: Eugene Grosbein Message-ID: <59590FE6.7030109@grosbein.net> Date: Sun, 2 Jul 2017 22:23:18 +0700 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.7.2 MIME-Version: 1.0 In-Reply-To: <87a84myitf.wl-herbert@mailbox.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=0.3 required=5.0 tests=BAYES_00,LOCAL_FROM autolearn=no autolearn_force=no version=3.4.1 X-Spam-Report: * -2.3 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * 2.6 LOCAL_FROM From my domains X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on hz.grosbein.net 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: Sun, 02 Jul 2017 15:23:37 -0000 02.07.2017 22:11, Herbert J. Skuhra пишет: > Eugene Grosbein skrev: >> >> 02.07.2017 21:03, Herbert J. Skuhra wrote: >>> Skype for Business (S4B) on Mac OS X 10.12.6 (Beta5) is actually >>> trying to connect over IPv4. The connection fails until I lower MTU to >>> 1440. After resetting MTU to 1500 and restarting S4B it connects fine >>> for a while ('route -n get' default shows 1500). I use 'set iface >>> enable tcpmssfix' in mpd5.conf and I've tried: >>> >>> - set iface mtu and set link mtu/mru/mrru in mpd5.conf >>> - set scrub ... max-mss in pf.conf >> >> Please show output of ifconfig command for external ng interface. > > ng0: flags=88d1 metric 0 mtu 1440 > inet6 fe80::XXX:XXXX:XXXX:XXXX%ng0 prefixlen 64 scopeid 0x7 > inet XX.XX.XX.XX --> XX.XX.XX.YY netmask 0xffffffff > nd6 options=21 'set iface enable tcpmssfix' in mpd.conf should be enough for you. Are you sure you have it in right point of the config? This is critical for it to take effect. Please see mpd.conf.sample for example. Doesn't mpd complain of this command to its log? Make sure you have 'log +iface +iface2' command in your mpd.conf, restart mpd5 and scan its log for 'tcpmssfix'. Can you send the log to me, it you still have the problem?