From owner-freebsd-stable@FreeBSD.ORG Thu Jul 12 20:38:07 2007 Return-Path: X-Original-To: freebsd-stable@freebsd.org Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 4912116A46C for ; Thu, 12 Jul 2007 20:38:07 +0000 (UTC) (envelope-from Stephen.Clark@seclark.us) Received: from smtpauth05.prod.mesa1.secureserver.net (smtpauth05.prod.mesa1.secureserver.net [64.202.165.99]) by mx1.freebsd.org (Postfix) with SMTP id 1251E13C4BC for ; Thu, 12 Jul 2007 20:38:06 +0000 (UTC) (envelope-from Stephen.Clark@seclark.us) Received: (qmail 11726 invoked from network); 12 Jul 2007 20:38:02 -0000 Received: from unknown (24.144.77.243) by smtpauth05.prod.mesa1.secureserver.net (64.202.165.99) with ESMTP; 12 Jul 2007 20:38:02 -0000 Message-ID: <46969129.60409@seclark.us> Date: Thu, 12 Jul 2007 16:38:01 -0400 From: Stephen Clark User-Agent: Mozilla/5.0 (X11; U; Linux 2.2.16-22smp i686; en-US; m18) Gecko/20010110 Netscape6/6.5 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Chuck Swiger References: <469624D1.20108@seclark.us> <4696823B.9020107@seclark.us> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-stable@freebsd.org Subject: Re: pmtud + ipnat RELENG_6_2 appears to be broken X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: Stephen.Clark@seclark.us List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 12 Jul 2007 20:38:07 -0000 Chuck Swiger wrote: >On Jul 12, 2007, at 12:34 PM, Stephen Clark wrote: > > >>Did something change in 6.2? If my mtu size on rl0 is 1280 it won't >>accept a larger incoming packet. >> >> > >Nothing changed; that is the expected behavior. >(Modulo support for 4-byte VLAN tags.) > > > >>kernel: rl0: discard oversize frame (ether type 800 flags 3 len >>1514 > max >>1294) >> >>I don't think it worked this way in the past. >> >> > >Well, it did. :-) > > > >>Won't this affect pmtud? >> >> > >Nope. > > > >>man page for ifconfig says mtu limits size of "transmission" not >>reception. >> >> "mtu n Set the maximum transmission unit of the interface to >>n, default >> is interface specific." >> >> > >The MTU is actually defined in reference to a network segment such as >an "ethernet collision domain", and applies to all machines sending >traffic to that segment. If the MTU is really 1280, nobody else >should be sending larger packets, and the drivers will drop any >larger packets they receive and generate the appropriate ICMP error.... > > > Hi Chuck, First thanks for responding but thats the problem, this did't generate an icmp when the packet was dropped. kernel: rl0: discard oversize frame (ether type 800 flags 3 len 1514 > max 1294) This message did not result in any icmp packet. I was running tcpdump looking for them. Steve -- "They that give up essential liberty to obtain temporary safety, deserve neither liberty nor safety." (Ben Franklin) "The course of history shows that as a government grows, liberty decreases." (Thomas Jefferson)