Patent ID: 7860106

Claim:
A comparison device, comprising: a processor; and a memory including a set of instructions performed by the processor, the set including: storing a first routing table entry including a route descriptor and a first plurality of sorted prefix blocks, each prefix block corresponding to a subnet of a first network link and including first subnet information for the corresponding subnet, the first route descriptor describing each of the sorted prefix blocks within the first plurality of sorted prefix blocks as having the same routing information as the first network link, the first subnet information set for each subnet including a prefix, a mask and a cost; storing a second routing table entry including a second route descriptor and a second plurality of sorted prefix blocks, each prefix block corresponding to a subnet of a second network link and including second subnet information for the corresponding subnet the second route descriptor describing each of the sorted prefix blocks within the second plurality of sorted prefix blocks as having the same routing information as the second network link, the second subnet information set for each subnet including a prefix, a mask and a cost; and determining if the first routing table entry is different from the second routing table entry by comparing the route descriptor of the first routing table entry to the route descriptor of the second routing table entry.