Date: Wed, 12 Jan 2000 00:42:46 +0000 From: Brian Somers <brian@Awfulhak.org> To: Marc van Kempen <marc@bowtie.nl> Cc: Brian Somers <brian@Awfulhak.org>, Martin Welk <mw@theatre.sax.de>, Christoph Kukulies <kuku@gilberto.physik.RWTH-Aachen.DE>, freebsd-isdn@FreeBSD.ORG, brian@hak.lan.Awfulhak.org, brian@hak.lan.Awfulhak.org Subject: Re: one slight glitch in i4bispp Message-ID: <200001120042.AAA01200@hak.lan.Awfulhak.org> In-Reply-To: Message from Marc van Kempen <marc@bowtie.nl> of "Tue, 11 Jan 2000 12:25:46 %2B0100." <200001111125.MAA16896@bowtie.nl>
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> > > ppp(8) :-) > > > > If you enable -nat and -auto, ppp will keep the interface addresses > > previously assigned and NAT them for you. This means that the > > ``first connection'' will end up being NAT'd from the start (it's > > bound to the old address but the peer has only ever seen the new > > address). > > > > I'm a bit puzzled as to how this would work, what you say is this: > > You telnet from your machine to telnet.domain.com: > > telnet.domain.com <----> [dynamic ip] -- PPP,NAT -- [first ipnr] <---> telnet > > So the tcp packet going from my machine to telnet.domain.com has as it's > source address the dynamic IP address, as NAT'ed by PPP, the first ipnr > is only seen on my machine. > > But when the connection times out and I get another dynamic IP nr, how > is my tcp connection going to survive, isn't the socket on telnet.domain.com > bound to my old (dynamic) ip nr? No, well not if the initial telnet packet caused the ``ppp -nat'' process to dial. Because it decides based on the unNATd packet, it brings the link up and then (after IPCP has agreed another IP number) sends the packet through the NAT engine. telnet.domain.com only ever sees packets from the new IP number whereas the telnet process is bound to the old IP number. > Regards, > Marc. > > > -- > ---------------------------------------------------- > Marc van Kempen BowTie Technology > Email: marc@bowtie.nl WWW & Databases > tel. +31 40 2 43 20 65 > fax. +31 40 2 44 21 86 http://www.bowtie.nl > ---------------------------------------------------- -- Brian <brian@Awfulhak.org> <brian@FreeBSD.org> <http://www.Awfulhak.org>; <brian@OpenBSD.org> Don't _EVER_ lose your sense of humour ! <brian@FreeBSD.org.uk> To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isdn" in the body of the message
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