Date: Wed, 19 Jun 2002 18:14:06 -0400 From: Damian Gerow <freebsd@coal.sentex.ca> To: freebsd-net@freebsd.org Subject: Re: tracking down strange MTU issues with PPPoE) Message-ID: <MPG.177acc3b4b47703811e1a342@marble.sentex.ca> In-Reply-To: <20020619014519.A20138@tp.databus.com>
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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.<concentrator type>-<viewpoint> and windows.<PPPoE program>, 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
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