From owner-freebsd-mobile@FreeBSD.ORG Tue Oct 11 14:16:32 2005 Return-Path: X-Original-To: freebsd-mobile@freebsd.org Delivered-To: freebsd-mobile@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 46EDF16A445 for ; Tue, 11 Oct 2005 14:16:32 +0000 (GMT) (envelope-from roth@droopy.unibe.ch) Received: from mailhub04.unibe.ch (mailhub04.unibe.ch [130.92.9.71]) by mx1.FreeBSD.org (Postfix) with ESMTP id CC5AD43D66 for ; Tue, 11 Oct 2005 14:16:30 +0000 (GMT) (envelope-from roth@droopy.unibe.ch) Received: from localhost (scanhub03.unibe.ch [130.92.254.67]) by mailhub04.unibe.ch (Postfix) with ESMTP id F116114C78; Tue, 11 Oct 2005 16:16:28 +0200 (CEST) Received: from mailhub04.unibe.ch ([130.92.9.71]) by localhost (scanhub03.unibe.ch [130.92.254.67]) (amavisd-new, port 10024) with LMTP id 24928-05-65; Tue, 11 Oct 2005 16:16:27 +0200 (CEST) Received: from asterix.unibe.ch (asterix.unibe.ch [130.92.64.4]) by mailhub04.unibe.ch (Postfix) with ESMTP id 2F29814CAB; Tue, 11 Oct 2005 16:16:27 +0200 (CEST) Received: from droopy.unibe.ch (droopy [130.92.64.20]) by asterix.unibe.ch (8.12.10+Sun/8.12.10) with ESMTP id j9BEGRdB028954; Tue, 11 Oct 2005 16:16:27 +0200 (MEST) Received: (from roth@localhost) by droopy.unibe.ch (8.12.10+Sun/8.12.9/Submit) id j9BEGRUZ006727; Tue, 11 Oct 2005 16:16:27 +0200 (MEST) Date: Tue, 11 Oct 2005 16:16:27 +0200 From: Tobias Roth To: "Rehsack Jens (ext)" Message-ID: <20051011141627.GA6499@droopy.unibe.ch> Mail-Followup-To: "Rehsack Jens (ext)" , freebsd-mobile@freebsd.org References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4i X-message-flag: Warning! Using Outlook is insecure and promotes virus distribution. Please use a different email client. X-Virus-checked: by University of Berne Cc: freebsd-mobile@freebsd.org Subject: Re: Help needed: cannot send packets larger 230 bytes via vodafone umts X-BeenThere: freebsd-mobile@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Mobile computing with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 11 Oct 2005 14:16:32 -0000 On Tue, Oct 11, 2005 at 02:19:42PM +0200, Rehsack Jens (ext) wrote: > > > > > > I started some diagnostics why my web wont work, and detected > > > that packets larger than 229 byte payload via ping will swallowed > > > by the connection (I don't know where). > > > > Did you try traceroute with a packetlength larger than your 229 bytes > > to see where the packets get dropped and for what reason? > > > > greets, t. > > Now I did ;) > > And horribly I had to see, that traceroute seems to transport even > larger packets an get's the wanted answers. I also tried after that > shock >traceroute -P TCP< and seen, that it works, too. Initially, my theory was that you have a problem with pathMTU, but I am not so sure anymore. If pathMTU is broken, telnetting to port 80 won't work, since the packets sent have the DF bit set and thus cannot be fragmented. When tracerouting with udp or tcp, they don't have that bit set, so they get fragmented and things work. However, this does not explain why your icmp pings don't get through if larger than 229 bytes. One last idea: You may try to lower the mtu of your ppp interface with ifconfig down to 229 and see if telnet then works. If so, you might have an mtu problem after all, if not, something else is rotten. good luck, t.