From owner-freebsd-net@freebsd.org Sun Jul 2 15:12:02 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 5D384DA7C83 for ; Sun, 2 Jul 2017 15:12:02 +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 1BD206E0C2 for ; Sun, 2 Jul 2017 15:12:01 +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 E167946B84; Sun, 2 Jul 2017 17:11:58 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mailbox.org; h= content-type:content-type:mime-version:references:in-reply-to :subject:subject:from:from:message-id:date:date:received; s= mail20150812; t=1499008317; bh=XtHuWboNhz3Qde6IZwVLrhHn/8gwdQm2N NlOEFMM230=; b=D+HiDMNAM+Gc7HD1kJDLqypGsuhjeT8cydnwGMluNE/8wzsAJ cdx62XdM77h1yiX+SrA50nri5jbLS1+WGAWgSjUTlAgytRGWvb1cRUJkGP7vqqzu JDKtwPOsVhQiHUG3IsSmZc+pRK1yT/8eydQqzgBxIurTkoOATIEWHEQKqggu4DWZ tLFk5vbOv3Ye6SuZJqD3ieQFI/2PeKCUN7Ao1rWApywgrOOH/87skmqApK6Hs0uS ER/xEjHqhMYJxBkG2Ps90V0M3VKcGNiiZWgZ3LedCWQ639yMcUTarBG+zBO/pfM/ VAi8NhueErtYH1MJlxANUjFUAe35wqbYR+ctw== X-Virus-Scanned: amavisd-new at heinlein-support.de Received: from smtp1.mailbox.org ([80.241.60.240]) by spamfilter01.heinlein-hosting.de (spamfilter01.heinlein-hosting.de [80.241.56.115]) (amavisd-new, port 10030) with ESMTP id JTuS7HJjNcvF; Sun, 2 Jul 2017 17:11:57 +0200 (CEST) Date: Sun, 02 Jul 2017 17:11:56 +0200 Message-ID: <87a84myitf.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: <59590064.1040700@grosbein.net> References: <87r2xzaw30.wl-herbert@mailbox.org> <87bmp3x7eu.wl-herbert@mailbox.org> <59590064.1040700@grosbein.net> MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII 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 15:12:02 -0000 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 -- Herbert