From owner-freebsd-net Wed Jun 19 15:18:17 2002 Delivered-To: freebsd-net@freebsd.org Received: from obsidian.sentex.ca (obsidian.sentex.ca [64.7.128.101]) by hub.freebsd.org (Postfix) with ESMTP id 69B6937BA94 for ; Wed, 19 Jun 2002 15:12:51 -0700 (PDT) Received: from 192.168.42.92 (pyroxene.sentex.ca [199.212.134.18]) by obsidian.sentex.ca (8.12.2/8.12.2) with SMTP id g5JMCo7T082728 for ; Wed, 19 Jun 2002 18:12:50 -0400 (EDT) (envelope-from damian@sentex.net) Date: Wed, 19 Jun 2002 18:14:06 -0400 From: Damian Gerow Subject: Re: tracking down strange MTU issues with PPPoE) To: freebsd-net@freebsd.org Message-ID: In-Reply-To: <20020619014519.A20138@tp.databus.com> X-Mailer: MicroPlanet Gravity v2.30 X-Virus-Scanned: By Sentex Communications (obsidian/20020220) Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org I've been working with Mike on this same problem, as I'm seeing it from my home machine. I took my home machine in to another DSL line with a Redback concentrator, and got full connect speeds -- it looks like it's something to do with the ERX. On Wed, 19 Jun 2002 01:45:19 -0400, barney@tp.databus.com stated: > There's something odd here - MSS does not include headers, and is 1460 > on a straight ethernet connection. So your MSS of 1452 equates to an > MTU of 1492. > > I'd try setting MTU (or MSS) way down, to 1024. If that works, you can > do a binary search to find the max working value. Like Mike said, I've tried this as well, to no avail. > You haven't shown enough of the dump to see if DF is set in packets from > either the working or non-working host, or to see just how big the packets > are. We've done a bunch of testing, and just for fun, I've put up the binary tcpdump output on: http://www.sentex.net/~damian/tcpdump Text versions can be found in text/. It's named by freebsd.- and windows., both of these from the viewpoint of the ISP. All dumps are getting ftp://ftp.isc.org/isc/bind9/9.2.1/bind-9.2.1.tar.gz. Maybe that will help a bit...? To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message