From owner-freebsd-hackers Sun Dec 7 19:22:48 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id TAA21889 for hackers-outgoing; Sun, 7 Dec 1997 19:22:48 -0800 (PST) (envelope-from owner-freebsd-hackers) Received: from anlsun.ebr.anlw.anl.gov (anlsun.ebr.anlw.anl.gov [141.221.1.2]) by hub.freebsd.org (8.8.7/8.8.7) with SMTP id TAA21861; Sun, 7 Dec 1997 19:22:38 -0800 (PST) (envelope-from cmott@srv.net) Received: from darkstar.home (ras537.srv.net [205.180.127.37]) by anlsun.ebr.anlw.anl.gov (8.6.11/8.6.11) with SMTP id UAA10489; Sun, 7 Dec 1997 20:22:30 -0700 Date: Sun, 7 Dec 1997 20:21:56 -0700 (MST) From: Charles Mott X-Sender: cmott@darkstar.home Reply-To: Charles Mott To: Eivind Eklund cc: Brian Somers , freebsd-hackers@FreeBSD.ORG Subject: Re: Route behaviour (was Re: cvs commit: src/usr.sbin/ppp command.c ppp.8 route.c) In-Reply-To: <8690twpu17.fsf@bitbox.follo.net> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk It seems like one would have to force the tunnel device to have a fixed IP address and perform NAT to the true interface address. In this case the FreeBSD box would be exactly like all of other other machines behind a NAT gateway, which means that non-supported IP encoding protocols would automatically break. Charles Mott On 8 Dec 1997, Eivind Eklund wrote: > Brian Somers writes: > > > brian 1997/12/06 20:09:16 PST > > > > Modified files: > > usr.sbin/ppp command.c ppp.8 route.c > > Log: > > Only allow one arg to `delete' - the mask & gateway aren't necessary. > > Delete AF_LINK routes as well as AF_INET. > > Allow the word `default' as the arg to `delete' or in place of the > > first two args (dest & netmask) to `add'. > > Accept INTERFACE as the third arg to `add'. > > > > You can now say `add default interface' to create a default route > > through the tun interface. It's reported that subsequent bind()s > > will bind to a broadcast address and not to the address currently > > assigned to the tun device - this is the first step towards > > supporting that first connection that was around from before the > > dynamic IP negotiation.... > > I've been thinking a bit more about it, and now I consider this > binding a bug. With an interface route to an interface with no > assigned address, we're actually sending packets onto the network that > hasn't got a legit source address. > > This works for the single case where there is a NAT engine at the > other end of that link, but that is also the _only_ case it works for. > > I'm still a bit uncertain about what would be the best approach - > probably binding to another interface in the machine. That's weird > too, but probably less surprising never the less > > What do other people think? Is this feasible given the way routing is > implemented in the FreeBSD kernel? > > Eivind. >