Patent ID: 9736110
Date: 2017-08-15
CPC Classifications: H04L

Claim:
1. A method for acquiring an Internet Protocol (IP) address by a Dynamic Host Configuration Protocol (DHCP) client, applied in a network comprising a controller and at least one switch, the method comprising: generating, by the controller, a first DHCP discover packet; sending, by the controller, the first DHCP discover packet to all switches in the network so that a switch directly connected to a DHCP server forwards the first DHCP discover packet to the DHCP server, and after the DHCP server generates a DHCP offer packet corresponding to the first DHCP discover packet, the DHCP server sends the DHCP offer packet to the switch directly connected to the DHCP server, wherein the DHCP offer packet comprises address information of the DHCP server; receiving, by the controller, a packet reported by the switch directly connected to the DHCP server, wherein the packet comprises the DHCP offer packet and a port of the switch directly connected to the DHCP server to communicate with the DHCP server; acquiring, by the controller, the address information of the DHCP server according to the DHCP offer packet; generating, by the controller according to the address information and the port, a forwarding rule for forwarding from a switch in a forwarding path between the DHCP client and the DHCP server to the DHCP server; sending, by the controller, the forwarding rule to the switch in the forwarding path between the DHCP client and the DHCP server so that the switch in the forwarding path between the DHCP client and the DHCP server forwards, to the DHCP server and according to the forwarding rule, a second DHCP discover packet from the DHCP client, and then the DHCP server allocates an IP address of the DHCP client to the DHCP client, wherein the forwarding rule is used to indicate a network path from the switch in the forwarding path between the DHCP client and the DHCP server to the DHCP server, and wherein the second DHCP discover packet is sent when the DHCP client needs to acquire the IP address of the DHCP client.