Abstract: When an automatic address assignment apparatus is operating in a network, another automatic address assignment apparatus stops the automatic address assignment service thereof. When a wireless LAN access point which functions as an automatic address assignment apparatus (DHCP server device) sends a DHCP discover message on the network and a DHCP offer message is returned as a response therefor, and when the address of the transmission source of the DHCP offer message does not match the IP address thereof, it is determined that another DHCP server exists on the network, and the DHCP server service of the former DHCP server is stopped. Thus, by avoiding contention with another DHCP server and by preventing confusion of the network, a wireless LAN access point suitable, in particular, for use in a small-scale office or a home network managed by an ordinary user having no knowledge of IP can be formed.

Abstract: When an automatic address assignment apparatus is operating in a network, another automatic address assignment apparatus stops the automatic address assignment service thereof. When a wireless LAN access point which functions as an automatic address assignment apparatus (DHCP server device) sends a DHCP discover message on the network and a DHCP offer message is returned as a response therefor, and when the address of the transmission source of the DHCP offer message does not match the IP address thereof, it is determined that another DHCP server exists on the network, and the DHCP server service of the former DHCP server is stopped. Thus, by avoiding contention with another DHCP server and by preventing confusion of the network, a wireless LAN access point suitable, in particular, for use in a small-scale office or a home network managed by an ordinary user having no knowledge of IP can be formed.

Abstract: When an automatic address assignment apparatus is operating in a network, another automatic address assignment apparatus stops the automatic address assignment service thereof. When a wireless LAN access point which functions as an automatic address assignment apparatus (DHCP server device) sends a DHCP discover message on the network and a DHCP offer message is returned as a response therefor, and when the address of the transmission source of the DHCP offer message does not match the IP address thereof, it is determined that another DHCP server exists on the network, and the DHCP server service of the former DHCP server is stopped. Thus, by avoiding contention with another DHCP server and by preventing confusion of the network, a wireless LAN access point suitable, in particular, for use in a small-scale office or a home network managed by an ordinary user having no knowledge of IP can be formed.

Abstract: The present invention provides a production method of thrombin which can convert prothrombin into thrombin highly efficiently even in the absence of thromboplastin and blood plasma, easily obtain a starting material for use in the conversion of prothrombin into thrombin, and prepare and purify thrombin in an industrial scale. It is characterized in treating a prothrombin-containing aqueous solution with a Ca salt at 0 to 15.degree. C.