oroute_find_ent(port_nr, dest) attempts first to find a route for the ip address dest, oroute_find_ent()'s second parameter, in the output route cache (i.e., output_hash_table[][]). If the route isn't in the cache, oroute_find_ent() looks for the route in the main output routing table (i.e., oroute_table[]) and then places the route in the output route cache.