| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide high security by equipping a DCHP server with a function of authenticating an IP-address assigned client and releasing an IP address when an unallowed client is found and a function of reporting communication rejection. SOLUTION: The DHCP server 10 when receiving requests to assign IP addresses from clients 40 and 60 checks whether or not their MAC addresses are registered in an allowed client MAC address DB 20, and allocates and records the IP addresses in an allocated-address DB while making them correspond to the MAC addresses when they are registered. Then an ARP packet is sent periodically to the IP addresses and it is checked whether or not a combination of the transmission source MAC address and the transmission source IP address in its response packet is recorded in the allocated address database, when it is recorded, a regular client is decided and when not, an irregular client is decided.</p> |
