From owner-freebsd-net Mon Nov 26 18:20:24 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 DE09937B41A for ; Mon, 26 Nov 2001 18:20:16 -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 SAA06174; Mon, 26 Nov 2001 18:03:30 -0800 (PST) Date: Mon, 26 Nov 2001 18:03:30 -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: <004801c176e6$e57a2eb0$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 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) > > I have an ethereal trace of a hanging telnet session from my desktop to one > of the gateway machines, and the corresponding tcpdump trace of the same > session on the gateway. Since I'm not too familiar with TCP/IP at such a > low level, I was wondering if anyone would be willing to take a look at the > two dumps and see if there is anything strange going on. > > Thanks, > > -- > Matt Emmerton > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-net" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message