Neighbor Discovery for IPV6 Switching Systems

Abstract

A distributed neighbor discovery module is disclosed where all neighbor discovery operations and functionalities may be distributed to a switch device processor. Each neighbor discovery process on a switch device may run as an individual neighbor discovery router node. There may be no coordination between neighbor discovery processes occurring on different switch devices. All other traffic, including both IPv6 control traffic and data traffic destined to the router may be processed by the central controller processor.

What is claimed is: 
     
         1 . An apparatus comprising:
 a memory; and   a processor coupled to the memory, wherein the processor is operative to:   perform a number of neighbor discovery processes using the same router IP address and the same router MAC address;   receive a multicast neighbor discovery packet from a host;   if the multicast neighbor discovery packet is destined to a plurality of nodes, handle the multicast neighbor discovery packet with a local neighbor discovery process; and   if the multicast neighbor discovery packet is destined to a solicited node address and the multicast discovery packet destination matches the local solicited node address, handle the multicast neighbor discovery packet with a local neighbor discovery process.   
     
     
         2 . The apparatus of  claim 1 , wherein the memory further comprises:
 a MAC table for storage of the router MAC address; and   a FIB CAM for storage of the router IP address.   
     
     
         3 . The apparatus of  claim 2 , wherein the processor is further configured to flood the multicast neighbor discovery packet to other hosts on the same VLAN connected to the apparatus after the neighbor discovery process. 
     
     
         4 . The apparatus of  claim 1 , wherein the processor is further configured to:
 receive a unicast neighbor discovery packet;   perform an L2 lookup for the router MAC address;   if the router MAC address is hit, perform an L3 lookup for an neighbor discovery access list; and   punt the unicast neighbor discovery packet to a local CPU.   
     
     
         5 . The apparatus of  claim 4 , wherein the apparatus is a switching device with a plurality of ports. 
     
     
         6 . The apparatus of  claim 1 , wherein the processor is further configured to:
 receive a unicast neighbor discovery packet from a host target directed to a second switching device on the same VLAN as the apparatus;   perform an L2 lookup that produces a miss;   replicate the unicast neighbor discovery packet; and   flood the replicated packets to other hosts on the same VLAN.   
     
     
         7 . The apparatus of  claim 5 , wherein the neighbor discovery access list comprises a list of acceptable neighbor discovery message types. 
     
     
         8 . A method comprising:
 performing a number of neighbor discovery processes using the same router IP address and the same router MAC address;   receiving multicast neighbor discovery packets from a host;   when a first one of the multicast neighbor discovery packets is destined to a plurality of nodes, handling the multicast neighbor discovery packet with a local neighbor discovery process; and   when a second one of the multicast neighbor discovery packets is destined to a solicited node address and the multicast discovery packet destination matches the local solicited node address, handling the multicast neighbor discovery packet with a local neighbor discovery process.   
     
     
         9 . The method of  claim 8 , wherein the memory further comprises:
 a MAC table for storage of the router MAC address; and   a FIB CAM for storage of the router IP address.   
     
     
         10 . The method of  claim 9 , further comprising flooding the multicast neighbor discovery packet to other hosts on the same VLAN connected to the apparatus after the neighbor discovery process. 
     
     
         11 . The method of  claim 8 , further comprising:
 receiving a unicast neighbor discovery packet;   performing an L2 lookup for the router MAC address;   when the router MAC address is hit, performing an L3 lookup for an neighbor discovery access list; and   punting the unicast neighbor discovery packet to a local CPU.   
     
     
         12 . The method of  claim 11 , wherein the apparatus is a switching device with a plurality of ports. 
     
     
         13 . The method of  claim 8 , further comprising:
 receiving a unicast neighbor discovery packet from a host target directed to a second switching device on the same VLAN as the apparatus;   performing an L2 lookup that produces a miss;   replicating the unicast neighbor discovery packet; and   flooding the replicated packets to other hosts on the same VLAN.   
     
     
         14 . The method of  claim 12 , wherein the neighbor discovery access list comprises a list of acceptable neighbor discovery message types. 
     
     
         15 . A computer-readable medium that stores a set of instructions which when executed perform a method comprising:
 performing a number of neighbor discovery processes using the same router IP address and the same router MAC address;   receiving multicast neighbor discovery packets from a host;   when a first one of the multicast neighbor discovery packets is destined to a plurality of nodes, handling the multicast neighbor discovery packet with a local neighbor discovery process; and   when a second one of the multicast neighbor discovery packets is destined to a solicited node address and the multicast discovery packet destination matches the local solicited node address, handling the multicast neighbor discovery packet with a local neighbor discovery process.   
     
     
         16 . The computer-readable medium of  claim 15 , wherein the memory further comprises:
 a MAC table for storage of the router MAC address; and   a FIB CAM for storage of the router IP address.   
     
     
         17 . The computer-readable medium of  claim 16 , further comprising flooding the multicast neighbor discovery packet to other hosts on the same VLAN connected to the apparatus after the neighbor discovery process. 
     
     
         18 . The computer-readable medium of  claim 15 , further comprising:
 receiving a unicast neighbor discovery packet;   performing an L2 lookup for the router MAC address;   when the router MAC address is hit, performing an L3 lookup for an neighbor discovery access list; and   punting the unicast neighbor discovery packet to a local CPU.   
     
     
         19 . The computer-readable medium of  claim 18 , wherein the apparatus is a switching device with a plurality of ports. 
     
     
         20 . The computer-readable medium of  claim 15 , further comprising:
 receiving a unicast neighbor discovery packet from a host target directed to a second switching device on the same VLAN as the apparatus;   performing an L2 lookup that produces a miss;   replicating the unicast neighbor discovery packet; and   flooding the replicated packets to other hosts on the same VLAN.