From owner-freebsd-net Tue Nov 27 2:47:18 2001 Delivered-To: freebsd-net@freebsd.org Received: from mailtoaster1.pipeline.ch (mailtoaster1.pipeline.ch [62.48.0.70]) by hub.freebsd.org (Postfix) with SMTP id AA9BD37B429 for ; Tue, 27 Nov 2001 02:47:10 -0800 (PST) Received: (qmail 97755 invoked from network); 27 Nov 2001 10:46:52 -0000 Received: from unknown (HELO pipeline.ch) ([62.48.21.59]) (envelope-sender ) by mailtoaster1.pipeline.ch (qmail-ldap-1.03) with SMTP for ; 27 Nov 2001 10:46:52 -0000 Message-ID: <3C036E9D.21808A44@pipeline.ch> Date: Tue, 27 Nov 2001 11:44:45 +0100 From: Andre Oppermann X-Mailer: Mozilla 4.76 [en] (Windows NT 5.0; U) X-Accept-Language: en MIME-Version: 1.0 To: Matthew Emmerton Cc: freebsd-net@freebsd.org Subject: Re: Very strange network behaviour - can anyone help me analyse tcpdump output? References: <004801c176e6$e57a2eb0$1200a8c0@gsicomp.on.ca> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit 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 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). This smells like MTU problems. Try to set the MTU on your physical LAN interfaces to something like 1480 or so any try again. -- Andre > 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"). > > 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