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.

1 . A router for directing traffic on a network, the router comprising: 
 a first address space including information relating to a destination address and information relating to forwarding of traffic for the destination address; and    a second address space including information relating to tunnel endpoint addresses, a tunnel endpoint address in the second address space being related to the forwarding information in the first address space.    
   
   
       2 . A router according to  claim 1 , wherein all addresses in the second address space are directly connected to a multi-point tunnel network.  
   
   
       3 . A router according to  claim 1 , wherein the tunnel endpoint address in the second address space is numerically identical to the address in the first address space.  
   
   
       4 . A router according to  claim 1 , wherein the address in the first address space is a link layer IP address and the tunnel endpoint address in the second address space is an internetwork layer IP address.  
   
   
       5 . A router according to  claim 1 , wherein a multipoint tunnel network is defined in the second address space.  
   
   
       6 . A router according to  claim 1 , wherein a routing protocol update is used to distribute routing information between nodes of the network.  
   
   
       7 . A router according to  claim 1 , wherein the receipt of an advertised next hop in a routing protocol update triggers the creation of a tunnel endpoint with an IP address in the second address space corresponding to the IP address in the first address space.  
   
   
       8 . A router according to  claim 1 , wherein a plurality of second address spaces are provided, corresponding to the definition of multiple tunnels.  
   
   
       9 . A router for directing traffic via a network, the network including a plurality of interconnected nodes, the router comprising: 
 a first address space for storing information received from nodes of the network, the information indicating a destination address and information as to how traffic for the destination address is to be forwarded via a specified node of the network; and    a second address space for storing information relating to how traffic is to be tunneled to a node of the network, the information indicating a destination address, the destination address in the second address space being related to an address of the specified node in the first address space;    wherein on receipt of routing information for the destination, the router re-directing the traffic for the destination by changing the address space of the next node from the first address space to the second address space.    
   
   
       10 . A method of creating a virtual private network via one or more networks owned by one or more internet service providers, the method comprising: 
 receiving information at a first node of the network that traffic for a destination is to the tunneled via a second node of the network, said information indicating that the traffic for the destination is to be tunneled to the node, said destination being part of a virtual private network; and    on receipt of routing information for the destination in the virtual private network, re-directing the traffic for the destination by changing the address space of the next node from a first address space to a second address space.    
   
   
       11 . A method according to  claim 10 , wherein the information is in a routing update received via the network.  
   
   
       12 . A method of redirecting traffic to be tunneled across a network, the method comprising: 
 deriving a link layer IP address of a multipoint tunnel endpoint from an internetwork layer IP address by making the link layer address numerically equivalent to the internetwork layer address, wherein the link layer address is in a first address space that is distinct from a second address space of the internetwork address; and    redirecting traffic by changing the address space of the next node from the first address space to the second address space.    
   
   
       13 . A method according to  claim 12 , wherein information relating to a node to be directed to is received in a routing advertisement.  
   
   
       14 . A method according to  claim 13 , wherein a multipoint tunnel network is defined in the second address space.  
   
   
       15 . A method according to  claim 14 , wherein a routing protocol update is used to distribute routing information between nodes of the network.  
   
   
       16 . A method according to  claim 14 , wherein the receipt of an advertised next hop in a routing protocol update triggers the creation of a tunnel endpoint with an IP address in the second address space corresponding to the IP address in the first address space.  
   
   
       17 . A method according to  claim 14 , wherein a plurality of second address spaces is provided, corresponding to the definition of multiple tunnels.