1. A method for reducing the time to determine data packet routes on a computer network, the method comprising the steps of: (a) perfoming a single lookup in a memory tree to find a particular first protocol forwarding entry in the memory tree to determine a first protocol route for a packet of data to be routed on the computer network, wherein the first protocol forwarding entry includes first protocol information for a first protocol and a cache of associated second protocol information for a second protocol different from the first protocol; and (b) retrieving and using the cached second protocol information in the determination of the first protocol route for the packet of data on the computer network.