On Fri, Jun 22, 2001 at 09:37:29AM -0700, Greg Varga wrote: > This is correct, in the workings... But I don't think it really breaks > the RFC's... It has nothing to do with the RFC's. > > Anyways this is the diffrence: > > All networks prefixed with "10.0"... > > Numbered: > ----- 10.0.1.1/24 [[[Linux Box]]] 10.0.0.100/24 -----Ethernet----- > 10.0.2.1/24 [[[Linux Box]]] 10.0.0.200/24 ----- > > Unnumbered: > ----- 10.0.1.1/24 [[[Linux Box]]] -----P to P----- [[[Linux Box]]] > 10.0.0.200/24 ----- > > As you can see, the unnumbered is a Point to Point connection, and acts > more like a "bridge"... > > Actually, if you want to do an Unnumbered connection with two Ethernet > Interfaces, thats exactly how I would set it up... as a Bridge. Either > that or use PPPoE and that should be able to do something simular. > > >Yes, it's cisco specific hack. > > No this is not true... Alot of the Point to Point (IE: Dial-Up, ISDN) > type Internet Connections use Unnumbered Connections. There are a > large number of companies that support these type of connections. You are correct, Greg. Unnumbered interfaces are (mostly) ptp interfaces. When setting up a ptp interface you should usually use one /30 in a traditional way. Now, for a ptp connection there is only one IP entity at the other end and it doesn't have to be one out of a /30. Any IP address will do. That's why they usually use the loopback IP (or the IP of another interface) to identify the Unnumbered interface. I'm not sure how this can be done with linux. But I think that pppd program does not require you to waste one /30 for the link. The server side can send one /32 to the client side and announce another IP (eg, the IP of its ethernet interface) as the peer IP of the ppp link. At least this is what's happening when you dial in to a NAS. Ramin > > --Greg.
