Date: Sun, 01 Feb 1998 14:12:44 +0000 From: Brian Somers <brian@Awfulhak.org> To: Andrew Ryder <aryder@bestweb.net> Cc: freebsd-questions@FreeBSD.ORG, Eivind Eklund <perhaps@yes.no> Subject: Re: ppp/pppd Message-ID: <199802011412.OAA26372@awfulhak.org> In-Reply-To: Your message of "Sat, 31 Jan 1998 08:21:40 EST." <Pine.BSF.3.96.980131082015.8942A-100000@barracuda.bestweb.net>
next in thread | previous in thread | raw e-mail | index | archive | help
[eivind cc'd 'cos he's interested in this stuff] > Does FreeBSD have anything for users with static ip(s) so there can be > ppp aliasing done like on an ethernet? I saw something on the man page for > ppp not pppd but wasnt sure if it was the type im talking about so > basically a static ip freebsd box could have two ips same as if it did > with ethernet. Nope. Currently ppp cleans the tun device when it starts up and keeps only one IP number assigned to it. Ppp may support multiple IP numbers in the future, but probably not in the way you expect. I'm thinking about the problem where a process starts up, binds a socket and sends a packet. The packet triggers a ppp dial and connects but reassigns the tun interface IP number because of ppp negotiations (this is all explained in http://www.FreeBSD.org/FAQ/userppp.html). The packet goes out, the target machine receives it and sends back a reply. The reply has nowhere to go because the target IP number is garbage. The originating process should send another packet, but, because the socket is bound to the wrong IP number, the same thing happens again. My plan is to treat the negotiated IP number as the primary interface IP, and any ``old'' IP numbers are assigned as aliases. Any outgoing packets will have their source IP compared against each of the aliases and will be tweaked and un-tweaked by the libalias engine so that the peer sees them as being from the primary IP. Whether or not the IP aliases are created in the first place will be a configurable ``alias'' option. Ie, the alias engine is a pre-requisite. Suddenly it's appropriate that both beasts are called ``aliasing'' :-) At the moment however, ppp is undergoing a serious shuffle so this stuff won't get done for a while. -- Brian <brian@Awfulhak.org>, <brian@FreeBSD.org>, <brian@OpenBSD.org> <http://www.Awfulhak.org>; Don't _EVER_ lose your sense of humour....
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199802011412.OAA26372>