A method for hierarchical configuration of domain name in IPv6 network, the method comprising: a) negotiating one unique user network's name between a user and a network service provider; configuring user network's name in an authentication server; b) a customer premises equipment at the user network side obtaining prefix of IPv6 network address and suffix of the user network's domain name by sessioning with a network access device, said suffix of the user network's domain name being consisting of the user network's name and suffix of the network service provider's domain name, the sessioning step in step b) is comprising: b1) conducting access authentication, and upon the success of the authentication, transmitting the user network's name to the network access device; and b2) executing DHCP involving a DHCP client, obtaining prefix of IPv6 network address and information of the network service provider's domain name, and further forming suffix of the user network's domain name c) the network access device further informing the network service provider's DNS server of establishing the resource record of said user network's domain name server, the resource record comprising the relationship between the customer premises equipment address and information of suffix of the user network's home domain name; and d) said customer premises equipment conducting address configuration and providing domain name service for a host at the user network side on the basis of the obtained prefix of IPv6 network address and suffix of the user network's domain name by configuring a DHCP server and DNS server, which are embedded in the Customer Premises Equipment, with the received information of the prefix of address and suffix of the home domain name; and wherein - hosts in the user network having a domain name comprising the suffix of the user networks domain name; - if an inquiring host away from the user network wants to access a host inside the user 35 network, - the inquiring host sends a DNS inquiry request, that is sent to the DNS server of the network service provider by the inquiring hosts local DNS server, - the DNS server of the network service provider directs this request to the DNS server of the CPE according to suffix of the domain name and redirection information configured on the network service provider's DNS server and - customer premises equipment sends the IP address of the requested user's host to the inquiring hosts local DNS server, which transmits the information to the inquiring host. a) negotiating one unique user network's name between a user and a network service provider; configuring user network's name in an authentication server; b) a customer premises equipment at the user network side obtaining prefix of IPv6 network address and suffix of the user network's domain name by sessioning with a network access device, said suffix of the user network's domain name being consisting of the user network's name and suffix of the network service provider's domain name, the sessioning step in step b) is comprising: b1) conducting access authentication, and upon the success of the authentication, transmitting the user network's name to the network access device; and b2) executing DHCP involving a DHCP client, obtaining prefix of IPv6 network address and information of the network service provider's domain name, and further forming suffix of the user network's domain name b1) conducting access authentication, and upon the success of the authentication, transmitting the user network's name to the network access device; and b2) executing DHCP involving a DHCP client, obtaining prefix of IPv6 network address and information of the network service provider's domain name, and further forming suffix of the user network's domain name c) the network access device further informing the network service provider's DNS server of establishing the resource record of said user network's domain name server, the resource record comprising the relationship between the customer premises equipment address and information of suffix of the user network's home domain name; and d) said customer premises equipment conducting address configuration and providing domain name service for a host at the user network side on the basis of the obtained prefix of IPv6 network address and suffix of the user network's domain name by configuring a DHCP server and DNS server, which are embedded in the Customer Premises Equipment, with the received information of the prefix of address and suffix of the home domain name; and - hosts in the user network having a domain name comprising the suffix of the user networks domain name; - if an inquiring host away from the user network wants to access a host inside the user 35 network, - the inquiring host sends a DNS inquiry request, that is sent to the DNS server of the network service provider by the inquiring hosts local DNS server, - the DNS server of the network service provider directs this request to the DNS server of the CPE according to suffix of the domain name and redirection information configured on the network service provider's DNS server and - customer premises equipment sends the IP address of the requested user's host to the inquiring hosts local DNS server, which transmits the information to the inquiring host.