Dynamically selecting a DHCP server for a DHCP client terminal device may include triggering, by a network device, an authentication performed by an authentication server on a DHCP client terminal device user when receiving a DHCP packet for requesting a configuration parameter sent from a DHCP client terminal device, receiving, by the network device, an identity of a DHCP server designated by the authentication server for the DHCP client terminal device user when the DHCP client terminal device user passes the authentication, and establishing an entry for user information of the DHCP client terminal device user and the identity of the designated DHCP server, and matching, by the network device, the user information carried in a packet with established entries when receiving the packet subsequently sent from the DHCP client terminal device, and forwarding the packet using the identity of the DHCP server in the entry matching the user information.