DYNAMIC LAN CONTROLLER SWITCHING METHOD

PROBLEM TO BE SOLVED: To shorten recovery time by simplifying recover processing by dynamically switching a LAN controller at the time of LAN controller fault by performing a TCP/IP protocol while using plural LAN controllers. SOLUTION: When a fault in a LAN controller 11 in a communication system 10 is detected, a fault report 20 is issued from a LAN controller control process 13. An IP control process 15 searches a LAN controller on the same network as the LAN controller 11 out of a local address table 30 and issues a MAC address change information 21. A LAN controller control process 14 sets the MAC address of LAN controller 12 to this information 21 and issues it onto the network. Receiving this information, a LAN controller process 13' of communication system 10' changes the MAC address of table coincident with the IP address informed by the MAC address change information 21 from an ARP cache table 31 according to this information and communicates it.