Patent ID: 7382769

Claim:
A method comprising: receiving, in a network router, routing information communicated by one or more routing protocols, wherein the routing information defines network routes; maintaining route data within the network router based on the received routes; designating, within the route data, a first portion of the routes as internal routes when the routing information that defines the first portion of the routes is received via an interior routing protocol for a local network to which the network router belongs; designating, within the route data, a second portion of the routes as external routes when the routing information that defines the second portion of the routes is received via an exterior routing protocol; receiving packets with the network router; after receiving the packets, associating each of the packets with one of the routes using the route data; after associating each packet with one of the routes, identifying a designation for the associated route; and selectively forwarding each of the packets based on the identified designation of the associated route by dropping any of the packets upon determining that (i) the packet is associated with a route that is designated within the route data as an internal route, and (ii) that the packet was received from a device external to the local network.