Method system and server for implementing dhcp address security allocation

The invention relates to a realizing method and system for DHCP safety address distribution. The diaphragm core is DHCP (handling a dynamic host configuration protocol) in transmit the DHCP discovery message through the network access; When the network access side obtaining the DHCP a client port information and an identity information, and based on to the identification information end of the authentication to; aFinally, DHCP server is authenticating to a client DHCP address distribution message. Therefore, the invention performing the access authentication to a user according to the position information, and is only the legitimate and user terminal distributed IP address, wherein enormously strengthened by way DHCP address distribution safety. Moreover, the invention can the address and a AAA management server, or by the AAA server authentication successfully distributed address.