Date: Tue, 27 Nov 2001 12:12:50 -0500 (EST) From: Matthew Emmerton <matt@gsicomp.on.ca> To: Andre Oppermann <oppermann@pipeline.ch>, julian@elischer.org Cc: freebsd-net@FreeBSD.ORG Subject: Re: Very strange network behaviour - can anyone help me analyse tcpdump output? Message-ID: <Pine.BSF.4.21.0111271041160.56896-100000@xena.gsicomp.on.ca> In-Reply-To: <3C036E9D.21808A44@pipeline.ch>
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On Tue, 27 Nov 2001, Andre Oppermann wrote: > 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. That's what I thought too. I checked, and ppp is doing the TPC MSS fixup. Even after removing the gif/ipsec stuff that I was doing (less overhead, and converting this installation into a plain LAN-behind-NAT setup), the problem persists. I tried dropping the MTU on my LAN interface to 1200 (from 1500), but that didn't change anything. If my ISP installed a bunch of really buggy hardware, would that explain why this started happening recently without any changes on my side? -- Matt Emmerton To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message
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