ROUTER DEVICE

PROBLEM TO BE SOLVED: To obtain a router device which can connect a user terminal connected to the LAN side to a network effectively. SOLUTION: In the router device 1 for routing data between an external network and a user terminal 13 on an internal network, the router device 1 comprises a WAN interface means 2 connected to the external network, a LAN interface means 4 connected to the user terminal 13 on the internal network, and a DHCP server means 5 for allocating an IP address to the user terminal 13 connected to the LAN interface means 4 subject to a DHCP. The DHCP server means 5 alters a first release period of the corresponding IP address set when the IP address is allocated to the user terminal 13, in response to a change of a network environment of an own device or the external network. COPYRIGHT: (C)2008,JPO&INPIT