From owner-freebsd-net Wed Aug 2 11:27:17 2000 Delivered-To: freebsd-net@freebsd.org Received: from bubba.whistle.com (bubba.whistle.com [207.76.205.7]) by hub.freebsd.org (Postfix) with ESMTP id 229BB37BD96; Wed, 2 Aug 2000 11:27:13 -0700 (PDT) (envelope-from archie@whistle.com) Received: (from archie@localhost) by bubba.whistle.com (8.9.3/8.9.3) id LAA98525; Wed, 2 Aug 2000 11:26:38 -0700 (PDT) (envelope-from archie) From: Archie Cobbs Message-Id: <200008021826.LAA98525@bubba.whistle.com> Subject: Re: Improved PPTP support for libalias(3) In-Reply-To: from Julian Elischer at "Aug 2, 2000 10:36:55 am" To: Julian Elischer Date: Wed, 2 Aug 2000 11:26:38 -0700 (PDT) Cc: Archie Cobbs , Ruslan Ermilov , Charles Mott , Erik Salander , net@FreeBSD.ORG, Brian Somers , Eivind Eklund X-Mailer: ELM [version 2.4ME+ PL68 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Julian Elischer writes: > > Sorry, I don't understand your point... libalias already does this fine, > > that's not the problem. > > > > The problem is that two internal clients connecting to the same > > external server at the same time will result in two TCP connections > > to the same server seeming to come from the same IP address, which > > violates the protocol. > > you could do this using the ipfw 'forward' keyword, > to redirect the streams from the clients to a proxy subprocess > in the natd process, which would aggregate as needed onto a separate > tcp stream it runs itself. > > I'm a little confused though. PPTP isn't running over > TCP.. or are you indicating that the TCP sreams under GRE > are 'fiddled' by natd? PPTP includes two components: a TCP control stream and a GRE transport layer. A control stream corresponds one-to-one with a remote peer IP address. Once a control stream is established, you may then establish one or more actual calls. Each of these calls gets a unique Call ID (unique to the control stream). The whole thing is predicated on there only being ONE control stream for each pair of servers. -Archie ___________________________________________________________________________ Archie Cobbs * Whistle Communications, Inc. * http://www.whistle.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message