United States Patent 7,356,031
Toebes , et al. April 8, 2008

Inter-v4 realm routing

Abstract

Packets may be forwarded between realms employing private unregistered addresses without the use of network address translation and/or application level gateways. Nodes within privately addressed realms are identified by a combination of their locally significant address and a globally significant realm address. The globally significant addresses are reserved in all realms for use as realm identifiers or inter-realm routing. To send a packet to a node within a distinct private realm, the packet is given an inner IP header designating the locally significant destination IP address of the target node within the remote realm and an encapsulation IP header indicating the globally significant address advertised by the gateway of the target node's realm. The globally significant address is used for forwarding outside the realm of the destination node. Once the packet reaches the destination realm, the locally significant address is used for forwarding.


Inventors: Toebes; John Albert (Cary, NC), Levy-Abegnoli; Eric (Nice, FR), Thubert; Pascal (La Colle sur Loup, FR)
Assignee: Cisco Technology, Inc. (San Jose, CA)
Appl. No.: 10/061,553
Filed: February 1, 2002

Full patent text at USPTO