A method of updating a routing table includes: receiving, from an issue-source node, a write packet that includes update data for updating the routing table; attempting to recognize, based upon contents of the write packet, a partition in which the issue-source node is included; determining whether to permit updating the routing table based upon (1) whether the partition including the source node is recognized and (2) whether port information and partition information in the update data are stored in the routing table; and updating the routing table when updating is permitted.