From owner-freebsd-net Tue Nov 27 1:20:24 2001 Delivered-To: freebsd-net@freebsd.org Received: from InterJet.elischer.org (c421509-a.pinol1.sfba.home.com [24.7.86.9]) by hub.freebsd.org (Postfix) with ESMTP id 2DCF637B798 for ; Tue, 27 Nov 2001 01:20:16 -0800 (PST) Received: from localhost (localhost.elischer.org [127.0.0.1]) by InterJet.elischer.org (8.9.1a/8.9.1) with ESMTP id BAA07527; Tue, 27 Nov 2001 01:03:17 -0800 (PST) Date: Tue, 27 Nov 2001 01:03:15 -0800 (PST) From: Julian Elischer To: Matthew Emmerton Cc: freebsd-net@FreeBSD.ORG Subject: Re: Very strange network behaviour - can anyone help me analyse tcpdump output? In-Reply-To: <006a01c176eb$172f6a20$1200a8c0@gsicomp.on.ca> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII 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 ok, well at least use the ability of ppp to 'forge' the mss negotiated.. that will also keep the packet sizes down. (It just sonds like that to me....) On Mon, 26 Nov 2001, Matthew Emmerton wrote: > > On Mon, 26 Nov 2001, Matthew Emmerton wrote: > > > > > Hi all, > > > > > > In the continuing saga of IPSec over PPPoE for a retail POS environment > that > > > I'm maintaing, the problems seem to become more complex as time goes on. > > > > > > The network is quite simple: > > > [ LAN #1 ] - [ FreeBSD Gateway #1 ] - [ ISP ] - [ FreeBSD Gateway #2 ] - > [ > > > LAN #2 ] > > > > > > Both LANs connect using PPPoE with the same ISP, and are one hop apart > > > (according to traceroute). > > > > > > The problem is that a connection from the Internet (anywhere) to either > of > > > the FreeBSD gateways will "hang". Usually I can login but doing an > 'ls -al' > > > will display a few lines of text and then nothing. This happens using a > > > bunch of telnet clients (Anzio on Win2K, Win2K and Win95 native, > FreeBSD) > > > from various ISPs, as well as *between* the gateways, so the problem is > most > > > definitely related to the ISP providing us service. However, they seem > to > > > think that it's our problem ("none of the customers that use Windows > have > > > this problem -- must be that Unix thing that you're using"). > > > > If you are using gif, make sure it has a small MTU (try 512 bytes) > > belmont.heers.on.ca# ifconfig gif0 > gif0: flags=8011 mtu 1280 > inet 10.0.2.2 --> 10.0.2.130 netmask 0xffffffff > belmont.heers.on.ca# ifconfig gif0 mtu 512 > ifconfig: ioctl (set mtu): Invalid argument > belmont.heers.on.ca# gifconfig gif0 mtu 512 > gifconfig: mtu: bad value > belmont.heers.on.ca# > > How am I supposed to change the MTU? > (These machines are running 4.3-RELEASE-p12) > > -- > Matt Emmerton > > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message