I've been reading up on the proxy-arp and have found 2 uses for it. 1. When you don't have a default gateway on a host, and the router sends it's MAC address to the host on an ARP request thereby having the host send the packet for another network to the router which will then forward it on. (Boy was that a run-on sentence or what?)
2. All hosts are configured with one subnet-mask (such as /24) and the router has a smaller subnet mask for each interface (such as /28). Proxy-arp works so that the subnetted network topology is transparent to the hosts. (See Illustration on page 71 of Jeff Doyle's CCIE Volume 1) My questions arise around the 2nd use. First why would anyone want to use such a setup? I was thinking maybe to divide a network while keeping address space, but after pondering that for longer thanI should have realized that wouldn't save any address space after all. If you did use such a setup what problems could arise? For instance let's say a host on one subnet sent a broadcast message to it's subnet, would the router forward it to the other subnet? Maybe I'll sleep on the subject some and do some more research later, but it would be nice to know if there are any real-world examples of this being implmented. Robert Fowler Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=38624&t=38624 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
