From owner-freebsd-net Wed Apr 19 14:32:16 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 9F80137B68A; Wed, 19 Apr 2000 14:32:12 -0700 (PDT) (envelope-from archie@whistle.com) Received: (from archie@localhost) by bubba.whistle.com (8.9.3/8.9.2) id OAA38818; Wed, 19 Apr 2000 14:32:09 -0700 (PDT) From: Archie Cobbs Message-Id: <200004192132.OAA38818@bubba.whistle.com> Subject: Re: Improved PPTP support for libalias(3) In-Reply-To: from Charles Mott at "Apr 19, 2000 03:18:02 pm" To: cmott@scientech.com (Charles Mott) Date: Wed, 19 Apr 2000 14:32:09 -0700 (PDT) Cc: archie@whistle.com (Archie Cobbs), ru@FreeBSD.ORG (Ruslan Ermilov), julian@elischer.org, brian@Awfulhak.org, ari@suutari.iki.fi, perhaps@yes.no, net@FreeBSD.ORG, erik@whistle.com (Erik Salander) X-Mailer: ELM [version 2.4ME+ PL54 (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 Charles Mott writes: > > I'm not that familiar with the libalias code (erik@whistle.com is > > more familiar), but am familiar with PPTP. Are you swizzling the > > TCP stream (port 1723) at all? If not, then it's probably not going > > to work .. or at least, not when two clients use the same Call ID. > > > > PPTP is like active mode FTP in that the Call ID (FTP -> port #) is > > embedded in the TCP stream and must be swizzled. Unlike FTP however, > > the TCP stream won't shrink or expand. > > It seems like the PPTP server address and call ID would provide > enough information to correctly rewrite packets (i.e. a given > server will not have duplicate call ID's). In practice, that may work, but AFAIK the call ID is scoped only to the control stream session, not to the entire server. So in theory at least you can have two separate TCP connections to the same server utilizing the same Call ID for different connections. -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