Patent ID: 8107482

Claim:
A method for routing a communication packet through a network switch device, the network switch device including at least one routing table and a plurality of switch ports, the method comprising: receiving a communication packet having a source address s and a destination address d at a switch port p; tagging the communication packet with a cost metric, the cost metric representing a path cost from a current location of the communication packet to the source address s; determining whether a valid routing table entry (s, p) exists in the at least one routing table; determining, for the destination address d, whether there is a switch port q for which a valid routing table entry (d, q) exists in the at least one routing table, the valid routing table entry (d, q) including the cost metric from the network switch device to the destination address d via the switch port q; routing the communication packet to the switch port q, if the valid routing table entries (s, p) and (d, q) exist in the at least one routing table; and routing the communication packet having the destination address d via the switch port q, the valid routing table entry (d, q) having a cost metric lower than or equal to a cost metric of all other entries (d, q′) where q′ is a switch port other than q.