From owner-freebsd-net@freebsd.org Sun Jul 2 20:31:36 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 A48D6DAC6F8 for ; Sun, 2 Jul 2017 20:31:36 +0000 (UTC) (envelope-from herbert@mailbox.org) Received: from mx2.mailbox.org (mx2.mailbox.org [80.241.60.215]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "*.mailbox.org", Issuer "SwissSign Server Silver CA 2014 - G22" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 611F275984 for ; Sun, 2 Jul 2017 20:31:35 +0000 (UTC) (envelope-from herbert@mailbox.org) Received: from smtp1.mailbox.org (smtp1.mailbox.org [80.241.60.240]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx2.mailbox.org (Postfix) with ESMTPS id B7D3146092; Sun, 2 Jul 2017 22:31:32 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mailbox.org; h= content-transfer-encoding:content-type:content-type:mime-version :references:in-reply-to:subject:subject:from:from:message-id :date:date:received; s=mail20150812; t=1499027490; bh=+wzcBmZz0L H6dYMttRKQK8rVJarU849znh3wWRd9VQc=; b=b6sI1QLn2riYkc7XdDap08xxpB dpW5UYHptfUVPC2n3YhdJjU9SOvu474nMkJVA0TmwOZhGTlymtanFkDyn0nDwuuU 4UXX4it8o+2URxNlN06zIXmkEPTy8d9BLHiqMhxBkdwwZKuA0qkEJzBOEDDutzak /4+aEKMqPd9lqn2UeKbOiAN51uC2Pbxwp+mCjfYEQ3WlxBs6IBIWD8ZBS+OVyaNf pyxFr0a3Ypnoba/knF4OL8GJVeoW0QhRgeACt41i3fgiBXLlJwxErlDOwv4QPQtC nYTyJEGdwb/dwdd836J0LVi3plDe9eA0+i/0pRFFsriEyG7LOfhE+Aaj21vA== X-Virus-Scanned: amavisd-new at heinlein-support.de Received: from smtp1.mailbox.org ([80.241.60.240]) by spamfilter02.heinlein-hosting.de (spamfilter02.heinlein-hosting.de [80.241.56.116]) (amavisd-new, port 10030) with ESMTP id J68Nbdtw46Ph; Sun, 2 Jul 2017 22:31:30 +0200 (CEST) Date: Sun, 02 Jul 2017 22:31:29 +0200 Message-ID: <87eftytwbi.wl-herbert@mailbox.org> From: "Herbert J. Skuhra" To: Eugene Grosbein Cc: freebsd-net@FreeBSD.org Subject: Re: [Bug 220351] Path MTU discovery works only after resetting an internal interface MTU (mpd5, ng_nat, ipfw) In-Reply-To: <878tk6ydwt.wl-herbert@mailbox.org> References: <87r2xzaw30.wl-herbert@mailbox.org> <87bmp3x7eu.wl-herbert@mailbox.org> <59590064.1040700@grosbein.net> <87a84myitf.wl-herbert@mailbox.org> <59590FE6.7030109@grosbein.net> <878tk6ydwt.wl-herbert@mailbox.org> MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=KOI8-R Content-Transfer-Encoding: quoted-printable 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 20:31:36 -0000 Herbert J Skuhra skrev: > = > Eugene Grosbein skrev: >> = >> 02.07.2017 22:11, Herbert J. Skuhra =D0=C9=DB=C5=D4: >>> 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 M= TU 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=3D88d1 m= etric 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=3D21 >> = >> '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 f= or example. >> = >> Doesn't mpd complain of this command to its log? > = > No. > = >> Make sure you have 'log +iface +iface2' command in your mpd.conf, >> restart mpd5 and scan its log for 'tcpmssfix'. > = > mpd: [B1] IFACE: Connecting tcpmssfix > = > But when I disable IPv6 on my network everything is working... even > without tcpmssfix enabled. > = > Instead of enabling ipv6cp in mpd5 I've also tested with an IPv6 tunn= el > from HE... same issue. :-( Hmm, adding "mtu#1440" to /etc/rtadvd.conf apperently fixes these issues. Makes sense? -- Herbert