From owner-freebsd-mobile@FreeBSD.ORG Tue Oct 11 14:43:57 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 457E816A425 for ; Tue, 11 Oct 2005 14:43:57 +0000 (GMT) (envelope-from jens.rehsack.ext@siemensvdo.com) Received: from gecko.sbs.de (gecko.sbs.de [194.138.37.40]) by mx1.FreeBSD.org (Postfix) with ESMTP id 9677043D4C for ; Tue, 11 Oct 2005 14:43:55 +0000 (GMT) (envelope-from jens.rehsack.ext@siemensvdo.com) Received: from mail1.sbs.de (mail1.sbs.de [192.129.41.35]) by gecko.sbs.de (8.12.6/8.12.6) with ESMTP id j9BEhsDL002412; Tue, 11 Oct 2005 16:43:54 +0200 Received: from sbas063a.ww011.siemens.net (sbas063a.sbas.ww011.siemens.net [158.92.186.172]) by mail1.sbs.de (8.12.6/8.12.6) with ESMTP id j9BEhrQ8015831; Tue, 11 Oct 2005 16:43:53 +0200 Received: from krbdf7ma.ww011.siemens.net ([158.92.210.82]) by sbas063a.ww011.siemens.net with Microsoft SMTPSVC(6.0.3790.1830); Tue, 11 Oct 2005 16:43:53 +0200 Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable X-MimeOLE: Produced By Microsoft Exchange V6.5.7226.0 Date: Tue, 11 Oct 2005 16:43:52 +0200 Message-ID: X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: Help needed: cannot send packets larger 230 bytes via vodafone umts Thread-Index: AcXObmBEmjlVAB93TLu4YOR29CYStwAAq6nw From: "Rehsack Jens \(ext\)" To: "Tobias Roth" X-OriginalArrivalTime: 11 Oct 2005 14:43:53.0623 (UTC) FILETIME=[338A6A70:01C5CE72] 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 14:43:57 -0000 -----Original Message----- From: Tobias Roth [mailto:roth@iam.unibe.ch]=20 Sent: Tuesday, October 11, 2005 4:16 PM To: Rehsack Jens (ext) Cc: freebsd-mobile@freebsd.org Subject: Re: Help needed: cannot send packets larger 230 bytes via vodafone umts > On Tue, Oct 11, 2005 at 02:19:42PM +0200, Rehsack Jens (ext) wrote: > > > >=20 > > > > 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). > > >=20 > > > Did you try traceroute with a packetlength larger than your 229 bytes > > > to see where the packets get dropped and for what reason? > > >=20 > > > greets, t. > >=20 > > Now I did ;) > >=20 > > 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. >=20 > 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. >=20 > However, this does not explain why your icmp pings don't get through > if larger than 229 bytes. >=20 > 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. >=20 > good luck, t. setting net.inet.tcp.path_mtu_discovery=3D0 didn't change anything, but # ifconfig tun0 mtu 200 changes something. Now the DNS lookup wont work anymore, but I get response from my webserver. It's really slow, but it is there ;) And MTU 230 works both - dns & web. Now I think it could be time to look how to speed up the thing ;)