A method for obtaining a remote Internet Protocol, IP, address, comprising: receiving, by a first client, a first detection IP packet from a remote server through a Point to Point Protocol, PPP, interface via an access router (23, 43, 63, 83, 103), wherein the access router obtains routing information of the first client in advance, the first detection IP packet is transmitted periodically, and the first detection IP packet carries a first IP address allocated by the remote server for the first client using a remote Host Configuration Protocol, RHCP, wherein the remote server is a RHCP server (21, 41) and the first client is a RHCP client having a lower-level client cascaded to the first client, wherein the first detection IP packet is forwarded by the access router to the first client using a pre-configured routing table that maps a corresponding relation between a temporary maintenance IP address and a client ID or an IP address of the PPP interface, and the first IP address included in the routing information allocated by the remote server is the temporary maintenance IP address that enables the remote server to stop subsequent transmission of the first detection IP packet for the first client through at least the steps of using the obtained routing information of the first client from the remote server and the temporary maintenance IP address to configure the first client to obtain another maintenance IP address sent by a remote DHCP server; releasing the temporary maintenance IP address after the other maintenance IP address is allocated and sent by the remote server and is obtained by the first client; configuring the first IP address to be temporarily an IP address of the first client; and configuring the other maintenance IP address to be the IP address of the first client. receiving, by a first client, a first detection IP packet from a remote server through a Point to Point Protocol, PPP, interface via an access router (23, 43, 63, 83, 103), wherein the access router obtains routing information of the first client in advance, the first detection IP packet is transmitted periodically, and the first detection IP packet carries a first IP address allocated by the remote server for the first client using a remote Host Configuration Protocol, RHCP, wherein the remote server is a RHCP server (21, 41) and the first client is a RHCP client having a lower-level client cascaded to the first client, wherein the first detection IP packet is forwarded by the access router to the first client using a pre-configured routing table that maps a corresponding relation between a temporary maintenance IP address and a client ID or an IP address of the PPP interface, and the first IP address included in the routing information allocated by the remote server is the temporary maintenance IP address that enables the remote server to stop subsequent transmission of the first detection IP packet for the first client through at least the steps of using the obtained routing information of the first client from the remote server and the temporary maintenance IP address to configure the first client to obtain another maintenance IP address sent by a remote DHCP server; releasing the temporary maintenance IP address after the other maintenance IP address is allocated and sent by the remote server and is obtained by the first client; configuring the first IP address to be temporarily an IP address of the first client; and configuring the other maintenance IP address to be the IP address of the first client.