From owner-freebsd-net Mon Feb 22 17:24:48 1999 Delivered-To: freebsd-net@freebsd.org Received: from xylan.com (postal.xylan.com [208.8.0.248]) by hub.freebsd.org (Postfix) with ESMTP id DB91D116FF for ; Mon, 22 Feb 1999 17:24:44 -0800 (PST) (envelope-from wes@softweyr.com) Received: from mailhub.xylan.com by xylan.com (8.8.7/SMI-SVR4 (xylan-mgw 2.2 [OUT])) id RAA13201; Mon, 22 Feb 1999 17:24:13 -0800 (PST) Received: from utah.XYLAN.COM by mailhub.xylan.com (SMI-8.6/SMI-SVR4 (mailhub 2.1 [HUB])) id RAA02594; Mon, 22 Feb 1999 17:24:12 -0800 Received: from softweyr.com by utah.XYLAN.COM (SMI-8.6/SMI-SVR4 (xylan utah [SPOOL])) id SAA17321; Mon, 22 Feb 1999 18:24:09 -0700 Message-ID: <36D20337.2C1AA00E@softweyr.com> Date: Mon, 22 Feb 1999 18:24:07 -0700 From: Wes Peters Organization: Softweyr LLC X-Mailer: Mozilla 4.5 [en] (X11; U; FreeBSD 2.2.7-RELEASE i386) X-Accept-Language: en MIME-Version: 1.0 To: Joao Carlos Mendes Luis Cc: net@FreeBSD.ORG Subject: Re: IP frags from wcarchive ??? References: <199902222100.SAA02125@roma.coe.ufrj.br> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Joao Carlos Mendes Luis wrote: > > Hi, > > Does anybody have a hint on what could cause this ? > > Feb 22 17:49:13 madrid /kernel: ipfw: 20150 Reset TCP 209.155.82.18 146.164.53.65 in via ed0 Fragment = 182 > Feb 22 17:49:21 madrid last message repeated 5 times > > 209.155.82.18 is wcarchive.cdrom.com, 20150 is my ipfw rule that deny > every TCP incoming packet for a disallowed (not allowed in a previous > rule) port. The problem is why is it getting here fragmented. IIRC, > FreeBSD's TCP has path MTU discovery, right ? > > On my side, every hop is an ethernet or fddi, until the international link, > which has a 1500 byte mtu. Unless you have absolute control of the routing path, you're highly likely to encounter one or more routers that are broken with respect to path mtu discovery. -- Where am I, and what am I doing in this handbasket? Wes Peters +1.801.915.2061 Softweyr LLC wes@softweyr.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message