Abstract: A routing information management method adapted for a layer-3 switch is proposed. For each ARP entry in an ARP table, a processor assigns to the ARP entry an aging reference parameter that is identical to a quantity of those routing entries in an IP routing table whose next hop IP addresses are identical to the IP address of the ARP entry, and removes those ARP entries whose aging reference parameters are zero. For each routing entry in the IP routing table, when the next hop IP address of the routing entry is absent from the ARP table, the processor makes the routing entry serve as an inactive routing entry, proactively sends an ARP request for the inactive routing entry, and updates the ARP table based on a piece of ARP information received externally.