At 06:08 PM 4/7/02, Kent Browning wrote: >What is Router 1 and Router 2 were 2 different companies? They would have to >have different subnet IDs?
No, the router interfaces on the shared link should be on the same subnet. Logically they share the link between themselves. It's sort of a no-mans land that "belongs" to both companies. Even though one or the other company may actually "own" the link at Layers 8 and 9 (politics and economics), they both have the responsibly of keeping the link working. The basic answer is that each end of the link must be able to communicate directly with the other end. The router interfaces on the link must be able to communicate at the data-link layer and be able to find each other via ARP or Inverse ARP or some sort of static mapping. For this to work, they must be on the same subnet. Otherwise we would have that race condition being discussed in another thread. The routers would need a routing protocol to communicate but they couldn't get a routing protocol to work because they can't see other without it. Another option is to use unnumbered interface on the link between them. For example, we used to connect to our ISP with a router that had no address on its serial port. The ISP router interface at the other end of our link to the ISP was also unnumbered. It wasn't a great solution though because without an IP address, we couldn't ping it. There are many other advanced options too. For example, you might be able to set up a tunnel between the two routers if that link between them is actually an internetwork of some sort. Priscilla ________________________ Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=40777&t=40766 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
