| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce the switching time of a server to be substantially zero and to structure an inexpensive system with high availability by allowing an inquiry means to inquire an address of a 2nd server if there is no response from a 1st server to a client's inquiry about an address. SOLUTION: The computers of a server 10 (server name: AAA) and a server 12 (server name: BBB) are placed in operation. Clients 1 and 20 inquire IP addresses of the server 10 as a primary name server according to a name server list 24. The clients 1 and 20 once receiving answers from the server 10 recognizes that a communication with the server AAA is established. For example, the server 10 becomes unable to provide service normally at a certain point of time. The name server part or the server 10 does not answer an IP address, so the client 20 switches the inquiry destination of an IP address to the server 12 as a secondary name server according to the name server list 24.</p> |
