Redirecting network traffic through a multipoint tunnel overlay network using distinct network address spaces for the overlay and transport networks

Abstract

A method and apparatus for redirecting network traffic through a multipoint tunnel overlay network using distinct network address spaces for the overlay and transport networks. In an IP implementation, redirecting traffic to be tunneled across a network comprises deriving the transport IP address of a multipoint tunnel endpoint from the network IP address by making the transport address numerically equivalent to the network address, the transport address being in an address space distinct from the address space of the network address. Traffic is redirected by changing the address space of the next hop in a received routing advertisement.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is a divisional of U.S. patent application Ser. No. 10 / 270,409 filed Oct. 2, 2002 which is incorporated herein by reference as fully set forth herein, under 35 U.S.C. §120.FIELD OF THE INVENTION [0002] This invention generally relates to the field of internetworking in data communications. The invention relates more specifically to redirecting network traffic through a multipoint tunnel overlay network using distinct IP address spaces for the overlay and transport networks. BACKGROUND OF THE INVENTION [0003] The approaches described in this section could be pursued, but are not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section. [0004] An internet comprises a plurality of sites attached to a common n...

AI Technical Summary

Problems solved by technology

The disadvantages of this solution include: the need to use an address resolution protocol to provide the mapping between the IP address of the tunnel endpoint in the overlay network and the underlying transport address; and the allocation of address space by a service provider for the tunnel network such that all tunnel endpoints are provided with unique addresses, which are distinct from those of the transport network.

Address allocation and address resolution become more challenging if multiple service providers coordinate to provide the tunnel overlay network.

Coordinating addressing and address resolution on the overlay network in such a case is more complicated if all addresses need to be unique amongst the set of addresses on the overlay AND the transport network.

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