From owner-freebsd-net@FreeBSD.ORG Wed Jan 4 12:11:37 2012 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E1AD81065670; Wed, 4 Jan 2012 12:11:37 +0000 (UTC) (envelope-from sodynet1@gmail.com) Received: from mail-iy0-f182.google.com (mail-iy0-f182.google.com [209.85.210.182]) by mx1.freebsd.org (Postfix) with ESMTP id 9F9A38FC08; Wed, 4 Jan 2012 12:11:37 +0000 (UTC) Received: by iadj38 with SMTP id j38so40899109iad.13 for ; Wed, 04 Jan 2012 04:11:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=VJYQOIW3rVdXKtI1vO7jsFLkaD/zH/rx27XcD454Wp4=; b=k/ESxTop6+Eb1Qw0S2XAyn/05jsyHf7hhzCFtlYTTDbEKtxmv7In+eO4rHrkkGA3pa xrm9f6dEzNs+Rs9x65fgDa30BbmtrmRoZmCC3848Ez3Un3GnN4bXQJhDZrIaWYd0XeIg 7FQ8Huu3Gx5M5BBT5sL6AopzkycvMZWfM2gFU= MIME-Version: 1.0 Received: by 10.50.40.129 with SMTP id x1mr79829709igk.4.1325679097131; Wed, 04 Jan 2012 04:11:37 -0800 (PST) Received: by 10.231.41.206 with HTTP; Wed, 4 Jan 2012 04:11:37 -0800 (PST) In-Reply-To: <20120104120150.GG34721@FreeBSD.org> References: <20120104120150.GG34721@FreeBSD.org> Date: Wed, 4 Jan 2012 14:11:37 +0200 Message-ID: From: Sami Halabi To: Gleb Smirnoff Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-net@freebsd.org Subject: Re: kernel: nd6_setmtu0: new link MTU on ng29 (1218) is too small for IPv6 X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 04 Jan 2012 12:11:38 -0000 Hi, i just tested the last log: %tail /var/log/messages Jan 3 23:21:50 mpd2 kernel: nd6_setmtu0: new link MTU on ng92 (1218) is too small for IPv6 Jan 4 00:00:36 mpd2 kernel: nd6_setmtu0: new link MTU on ng105 (1218) is too small for IPv6 Jan 4 00:34:48 mpd2 kernel: nd6_setmtu0: new link MTU on ng105 (1218) is too small for IPv6 Jan 4 07:47:37 mpd2 kernel: nd6_setmtu0: new link MTU on ng100 (1218) is too small for IPv6 Jan 4 08:31:55 mpd2 kernel: nd6_setmtu0: new link MTU on ng116 (1218) is too small for IPv6 Jan 4 09:16:21 mpd2 kernel: nd6_setmtu0: new link MTU on ng123 (1218) is too small for IPv6 Jan 4 12:55:32 mpd2 kernel: nd6_setmtu0: new link MTU on ng53 (1218) is too small for IPv6 Jan 4 14:17:34 mpd2 kernel: nd6_setmtu0: new link MTU on ng120 (1218) is too small for IPv6 %ifconfig ng120 ng120: flags=88d1 metric 0 mtu 1218 inet 188.64.96.5 --> 188.64.102.171 netmask 0xffffffff so MTU is indeed 1218 Sami 2012/1/4 Gleb Smirnoff > On Wed, Jan 04, 2012 at 12:59:18PM +0200, Sami Halabi wrote: > S> I'm using a FreeBSD8.2-R-p5 in conjunction with MPD5.5 port for creating > S> pptp/l2tp tunnels. > S> > S> I'm using MPPC (Compression & Encryption), my current onfiguration i use > S> only IPv4. > S> > S> I keep getting in the logs the following: > S> Jan 4 08:31:55 mpd2 kernel: nd6_setmtu0: new link MTU on ng116 (1218) > is > S> too small for IPv6 > S> Jan 4 09:16:21 mpd2 kernel: nd6_setmtu0: new link MTU on ng123 (1218) > is > S> too small for IPv6 > S> Jan 4 12:55:32 mpd2 kernel: nd6_setmtu0: new link MTU on ng53 (1218) is > S> too small for IPv6 > S> > S> although the NG tunnels don't negotiate IPv6. > S> > S> a close look to the MPD log i see that this happens for connections that > S> set MRU/MTU 1400. > S> > S> I talked to MPD developer (Alexander Motin) and this isn't a MPD > problem, > S> rather than a kernel issue as the logs say. > > Message is logged by kernel, but MTU is set by userland. Can you check > value of MTU with ifconfig, looking at an interface from most recent > discussed message? Is it really 1218? > > -- > Totus tuus, Glebius. > -- Sami Halabi Information Systems Engineer NMS Projects Expert