From owner-freebsd-net Mon Apr 17 7:12:12 2000 Delivered-To: freebsd-net@freebsd.org Received: from relay.ucb.crimea.ua (relay.ucb.crimea.ua [212.110.138.1]) by hub.freebsd.org (Postfix) with ESMTP id BCA8F37B83D for ; Mon, 17 Apr 2000 07:11:22 -0700 (PDT) (envelope-from ru@ucb.crimea.ua) Received: (from ru@localhost) by relay.ucb.crimea.ua (8.9.3/8.9.3/UCB) id RAA89374; Mon, 17 Apr 2000 17:05:42 +0300 (EEST) (envelope-from ru) Date: Mon, 17 Apr 2000 17:05:42 +0300 From: Ruslan Ermilov To: Julian Elischer Cc: Brian Somers , Charles Mott , Ari Suutari , Eivind Eklund , net@FreeBSD.org Subject: Re: Improved PPTP support for libalias(3) Message-ID: <20000417170542.A61926@relay.ucb.crimea.ua> Mail-Followup-To: Julian Elischer , Brian Somers , Charles Mott , Ari Suutari , Eivind Eklund , net@FreeBSD.org References: <20000413191649.A19493@relay.ucb.crimea.ua> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.95.3i In-Reply-To: ; from Julian Elischer on Thu, Apr 13, 2000 at 09:47:18AM -0700 Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Thu, Apr 13, 2000 at 09:47:18AM -0700, Julian Elischer wrote: > > > On Thu, 13 Apr 2000, Ruslan Ermilov wrote: > > > Hi! > > > > For those of you who would like to review this change, I have made it > > available from my FreeBSD homepage: > > > > http://people.FreeBSD.org/~ru/libalias_pptp_patch.0 > > > > > > WHAT IS ADDRESSED IN THIS PATCH > > > > The current PPTP support in libalias(3) is limited to only one local IP > > address. > > > > This change "eliminates" this limitation by adding the new API function, > > PacketAliasRedirectPptp(). It takes three arguments: src_addr, dst_addr > > and alias_addr. The meaning of these arguments is fully identical to > > the corresponding arguments of PacketAliasRedirectPort(), i.e. dst_addr > > can be INADDR_ANY or any specific IP address, while src_addr/alias_addr > > could be INADDR_ANY to always match the default aliasing address set by > > PacketAliasSetAddress(). > > > > does this mean that only one PC at a time behind a NAT wall, can access a > particular machine? > i.e. two visitors with their own laptops from the same place, > cannot go back to the same host to read their mail..? > This is not a BAD restriction, but it is a restriction.. > If you mean two PCs, each with their own tunnel to the same host, this will not work. The problem here is that we need some "tag" to use with source and destination IP addresses, to successfully de-alias packets coming in. For TCP and UDP packets, there are port numbers. For ICMP echo/timestamp packets, there is an ID field. But unfortunately, there seems to be no such "tag" with PPTP protocols. -- Ruslan Ermilov Sysadmin and DBA of the ru@ucb.crimea.ua United Commercial Bank, ru@FreeBSD.org FreeBSD committer, +380.652.247.647 Simferopol, Ukraine http://www.FreeBSD.org The Power To Serve http://www.oracle.com Enabling The Information Age To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message