From owner-freebsd-net Sun Feb 4 18:26:44 2001 Delivered-To: freebsd-net@freebsd.org Received: from xena.gsicomp.on.ca (cr677933-a.ktchnr1.on.wave.home.com [24.43.230.149]) by hub.freebsd.org (Postfix) with ESMTP id 646BC37B65D; Sun, 4 Feb 2001 18:26:21 -0800 (PST) Received: from hermes (hermes.gsicomp.on.ca [192.168.0.18]) by xena.gsicomp.on.ca (8.11.1/8.9.3) with SMTP id f152OZi26799; Sun, 4 Feb 2001 21:24:35 -0500 (EST) (envelope-from matt@gsicomp.on.ca) Message-ID: <004301c08f1c$22a8adb0$1200a8c0@gsicomp.on.ca> From: "Matthew Emmerton" To: Cc: References: <000501c08ed2$2e1c5920$3227e540@johnny2k> <4.3.2.7.0.20010204201824.00bd33c0@mail.bsdchicks.com> Subject: Re: Firewalling a PPPoE, any easy workaround to MTU on lan stations ? Date: Sun, 4 Feb 2001 21:34:15 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4133.2400 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > At 10:22 4-2-01 -0800, Julian Elischer wrote: > >John Telford wrote: > > > > > > I'm putting a 4.2 R firewall in for a ppoe connection. (sympatico) > > > Is there any workaround I can use so I don't have to reduce the MTU on all > > > the internal stations ? > > > It's a mix of Windows 9x and Macs. And I've found only one utility capable > > > of adjusting MTU on Macs. > > > Can anything be done on the freebsd box as the traffic goes through it ? > > > Thanks in advance, John. > > > P.S. the pppoe setup went fine thanks to a page at www.sympaticousers.org > > > and some further notes at www.freebsddiary.org > > > > > >ppp now has an option where it will force the negotiated packet size > >of new tcp sessions going through it down. (i.e it fiddles with the packets) > >check the man page.. I THINK it may be in 4.2, if not it's in -Stable > > Actually, I have just been playing with this. Userland ppp has the 'set > mtu' command which will make ppp try and set that MTU at negotiation time. Isn't the proper command 'set tcpmssfixup'? Sure, 'set mtu' will allow you to set the MTU, but 'set tpmssfixup' will ensure that any MTU bashing (explained very nicely at http://renaud.waldura.com/doc/freebsd-pppoe/) is properly accounted for.. -- Matt Emmerton To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message