David, If you point a routers GLR to its interface, the router will issue an arp request for any destination that is unknown, even devices that are not on a connected segment. (this is the same behavior that most host OSes exhibit if you point their DG to their own IP) For this to work, you must have another device on that segment setup for proxy arp to answer those arp requests issued by the router. A Cisco router can act as a proxy arp device, so can firewalls.
If you simply tell the router its GLR is a certain IP address, it doesn't have to issue a lot of extraneous arp requests and will simply send all traffic directly to the IP address you specified as its GLR. Unless you have a specific reason for using proxy arp, its best practice to just tell the router specifically who its GLR is. (there are certain redundancy scenarios where the use of proxy arp might be useful) HTH, Kent -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Peck, David Sent: Tuesday, January 15, 2002 7:29 AM To: [EMAIL PROTECTED] Subject: Gateway of last resort [7:31997] I was under the impressions that the gateway of last resort was a actual interface on the router. if a router had two interfaces one 10.1.1.1/16 and 10.1.2.1/16 and 10.1.2.1 was connected to a firewall that has a address of 10.1.2.2 that the gateway of last resort would be 10.1.2.1 not 10.1.2.2 and the static route thru 10.1.2.1 would be 0.0.0.0/0 [1/0] via 10.1.2.1 not 0.0.0.0/0 [1/0] via 10.1.2.2 or does this matter ? Thanks Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=32016&t=31997 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
