From owner-freebsd-net Tue Jun 18 18:49: 8 2002 Delivered-To: freebsd-net@freebsd.org Received: from vinyl2.sentex.ca (vinyl2.sentex.ca [199.212.134.13]) by hub.freebsd.org (Postfix) with ESMTP id 1192737B409 for ; Tue, 18 Jun 2002 18:49:03 -0700 (PDT) Received: from house.sentex.net (cage.simianscience.com [64.7.134.1]) (authenticated bits=0) by vinyl2.sentex.ca (8.12.3/8.12.2) with ESMTP id g5J1n0dc064099; Tue, 18 Jun 2002 21:49:01 -0400 (EDT) (envelope-from mike@sentex.net) Message-Id: <5.1.0.14.0.20020618213845.01c42aa0@192.168.0.12> X-Sender: mdtancsa@192.168.0.12 X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Tue, 18 Jun 2002 21:47:00 -0400 To: Tom Samplonius From: Mike Tancsa Subject: Re: tracking down strange MTU issues with PPPoE) Cc: freebsd-net@FreeBSD.ORG In-Reply-To: References: <5.1.0.14.0.20020618191155.01c08f18@192.168.0.12> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed 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 At 05:16 PM 6/18/2002 -0700, Tom Samplonius wrote: > Possibly. There is a PPPoE session to the Redback (or ERX), then >usually a L2TP session to the ISP. A PPPoE client connecting to the >Redback (or ERX) should be told a valid MTU. PPP tunel to L2TP tunnel >raises some interesting possiblities. I wonder how much mucking about the >SMS does to the protocol. Obviously it is doing something, since the >Redback works, but the ERX does not. Or the Bell network is broken :) b) is always a possibility. Actually, there is some bug in the ERX where the setting "IP TUNNEL REASSEMBLY" gets turned off when doing unrelated configs. The first time we encountered this, we had no end of trouble for 2 days and tracking down the right people to talk to was insane. There are groups in Bell who look after the DSL concentrators, groups who look after the DSLAMS, groups who look after the ATM network, but it seems not one individual knows how all the components work together, or at least they are not reachable. At one point one of the ATM guys said something to the effect that this was a known bug and I had to set the MTU on my terminating router's ethernet to 1450. I asked why and where the document was to which he responded that he was not allowed to share such information..... whatever.... Its ironic that the old kids game of "broken telephone" comes into play with the telco :-( ... But, Brian@freebsd.org's suggestion of set max mtu did the trick. I am curious to know why this is necessary on the ERX and not on the SMSes. ---Mike -------------------------------------------------------------------- Mike Tancsa, tel +1 519 651 3400 Sentex Communications, mike@sentex.net Providing Internet since 1994 www.sentex.net Cambridge, Ontario Canada www.sentex.net/mike To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message