From owner-freebsd-net Thu Dec 14 2:48:46 2000 From owner-freebsd-net@FreeBSD.ORG Thu Dec 14 02:48:44 2000 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mail.ruhr.de (in-ruhr3.ruhr.de [212.23.134.2]) by hub.freebsd.org (Postfix) with SMTP id 45FBE37B404 for ; Thu, 14 Dec 2000 02:48:43 -0800 (PST) Received: (qmail 30913 invoked by alias); 14 Dec 2000 10:49:04 -0000 Received: (from ue@localhost) by nathan.ruhr.de (8.11.0/8.11.0) id eBEAmhH80461 for freebsd-net@freebsd.org; Thu, 14 Dec 2000 11:48:43 +0100 (CET) (envelope-from ue) Date: Thu, 14 Dec 2000 11:48:43 +0100 From: Udo Erdelhoff To: freebsd-net@freebsd.org Subject: Strange fragmentation needed message Message-ID: <20001214114843.A85041@nathan.ruhr.de> Mail-Followup-To: freebsd-net@freebsd.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Hi, I've been experiencing problems with TCP connections. The symptoms are: - I can't upload large (>5 KByte) files with ftp, the client reports "stalled" at file position 19456; the server receives only the first 1024 Bytes of the file. Downloads work just fine. - Sending mail (uucp-over-ip) takes a long time. uucico complains about a timeout, closes the connection, calls again and restarts after 1024 bytes (2048 for the third connection, etc). - cvsup fails with Establishing multiplexed-mode data connection Running Detailer failed: Network read failure: Connection timed out Will retry at ... Aborting and restarting cvsup will eventually result in a successfull run. The box runs -current (PRE_SMPNG), the connection to the outside is an ADSL line (768/128). I'm using ppp with the assorted netgraph modules and ipfw&natd for NAT. Using ppp -nat instead doesn't help. I've had to ignore the problems for some time due to RL. I've tried to analyse the network traffic and found the following messages with tcpdump -ni tun0 11:36:33.213801 212.185.239.152 > 212.185.239.152: icmp: 212.185.239.152 unreachable - need to frag (mtu 1480) 212.185.239.152 being *my* IP-address. I don't understand what's going on. Traffic for my machine shouldn't be routed into the tunnel (i.e. ppp should add a route to 127.0.0.1 for $MYADDR). And I don't understand the reason for them, either. What's going on? /s/Udo -- >Every program evolves until it is capable of sending email. Except Microsoft Exchange To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message