From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guy Van Den Bergh Date: Sun, 25 Mar 2001 19:29:30 +0000 Subject: Re: [LARTC] pointopoint flag Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lartc@vger.kernel.org bert hubert wrote: > On Sun, Mar 25, 2001 at 08:07:48PM +0200, Guy Van Den Bergh wrote: > > >>> You CAN use Ethernet in a point-to-point configuration, by the way. Saves >>> some IP adresses. >> >> How do you that? PPPoE (PPP over Ethernet)? This is more like ppp >> emulation over ethernet. And thus this introduces protocol overhead. >> >> What do you mean by this? I'm puzzled. > > > It's still ethernet. But instead of assigning a /30 with 4 IP addresses, you > just route to your device. Not rocket science, just saves IP addresses. > > Regards, > > bert hubert But you require the next hop to do proxy arp if you would like this to work! And certainly this is not a point-to-point configuration of ethernet. If you route to your device instead of your nexthop the kernel is going to send an arp request for de destination address, and if the destination is not on the lan, some router on the lan has to do proxy arp on behalf of the destination. Otherwise your packets will be dropped. The kernel still thinks the lan is a broadcast medium. I believe this is a lot more complicated than "just routing to your device"! Even if you have a crossconnect cable between two hosts or routers, the medium inbetween is still broadcast and not point-to-point. I know this discussion is going way too far into semantics, but as far as I know there is no such thing as point-to-point mode of ethernet. Guy _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://ds9a.nl/2.4Routing/