Router and method for configuring IP addresses of the router

• US 8,024,435 B2
• Filed: 11/17/2009
• Issued: 09/20/2011
• Est. Priority Date: 09/22/2009
• Status: Active Grant

• Current Assignee: Ambit Microsystems Limited (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Ambit Microsystems Limited (Hon Hai Precision Industry Co., Ltd.), Hon Hai Precision Industry Co., Ltd.
• Inventors: Guo, Hong-Jian, Liu, Yang
• Primary Examiner(s): Duong; Oanh
• Application Number:
  US12/619,768
• Publication Number:
  US 20110072120A1
• Time in Patent Office: 672 Days
• Field of Search: 709220-222, 709/250, 370/254
• US Class Current: 709/222
• CPC Class Codes: H04L 61/103 across network layers, e.g. resolution of network layer into physical layer addresses or address resolution protocol [ARP]
• CPC Class Codes: H04L 61/5014 using dynamic host configuration protocol [DHCP] or bootstrap protocol [BOOTP]

Abstract

A method for configuring IP addresses of a router broadcasts a dynamic host configuration protocol (DHCP) discover packet over a network for receiving a DHCP offer packet sent from the modem. The DHCP offer packet comprises the private IP address of the modem. The method further obtains the private IP address of the modem from the DHCP offer packet, and configures IP addresses of a WAN port and a LAN port of the router according to the private IP address of the modem, so as to allow the private IP address of the modem to be in the same network segment with the IP address of the WAN port but in different network segments with the IP address of the LAN port.

Claims

1. A router, comprising:

an internet protocol (IP) address searching module operable to broadcast a dynamic host configuration protocol (DHCP) discover packet over a network so as to search a private IP address of a modem connected with the router;

a packet receiving module operable to receive a DHCP offer packet from the modem, wherein the DHCP offer packet comprises the private IP address of the modem;

an IP address obtaining module operable to obtain the private IP address of the modem from the DHCP offer packet;

an IP address configuration module operable to configure IP addresses of a wide area network (WAN) port and a local area network (LAN) port of the router according to the private IP address of the modem, so as to allow the private IP address of the modem to be in the same network segment with the IP address of the WAN port but in different network segments with the IP address of the LAN port;

a storage system that stores an IP addresses list that records a plurality of IP addresses;

a determining module operable to determine whether a broadcast count of broadcasting the DHCP discover packet equals to a predetermined value upon the condition that there is no reply from the modem responding to the DHCP discover packet, so that the IP address searching module broadcasts the DHCP discover packet one more time upon the condition that the broadcast count is less than the predetermined value;

a list acquisition module operable to acquire the IP address list from the storage system upon the condition that the broadcast count equals to the predetermined value;

an IP address verification module operable to broadcast a plurality of address resolution protocol (ARP) packets via the network to verify if one of the IP addresses recorded in an IP address list is the private IP address of the modem; and

a processor that executes the IP address searching module, the packet receiving module, the IP address obtaining module, and the IP address configuration module.

2. The router as described in claim 1, wherein the DHCP discover packet comprises a source address 0.0.0.0, a destination address 255.255.255.255, and a media access control (MAC) address of the router.

3. The router as described in claim 1, wherein the plurality of IP addresses recorded in the IP address list comprise:

192.168.1.1, 192.168.2.1, 192.168.1.254, 10.0.0.1, and 172.16.254.1.

4. The router as described in claim 1, wherein each of the ARP packets comprises one IP address recorded in the IP address list.

5. The router as described in claim 1, wherein the IP address verification module is further operable to assign a default private IP address to the modem if there is no reply from the modem responding to the ARP packets.

6. A method for configuring IP addresses of a router, the method being performed by execution of computer readable program code by at least one processor, the method comprising:

broadcasting a dynamic host configuration protocol (DHCP) discover packet over a network;

receiving a DHCP offer packet from the modem, wherein the DHCP offer packet comprises a private IP address of the modem;

obtaining the private IP address of the modem from the DHCP offer packet;

configuring IP addresses of a WAN port and a LAN port of the router according to the private IP address of the modem, so as to allow the private IP address of the modem to be in the same network segment with the IP address of the WAN port but in different network segments with the IP address of the LAN port;

storing an IP addresses list that records a plurality of IP addresses into a storage system of the router;

determining whether a broadcast count of broadcasting the DHCP discover packet equals to a predetermined value upon the condition that there is no reply from the modem responding to the DHCP discover packet;

returning to the broadcasting upon the condition that the broadcast count is less than the predetermined value;

acquiring the IP address list from the storage system upon the condition that the broadcast count equals to the predetermined value;

broadcasting a plurality of address resolution protocol (ARP) packets via the network; and

locating the private IP address of the modem according to one of the ARP packets which is responded by the modem.

7. The method as described in claim 6, wherein the DHCP discover packet comprises a source address 0.0.0.0, a destination address 255.255.255.255, and a media access control (MAC) address of the router.

8. The method as described in claim 6, wherein each of the ARP packets comprises one IP address recorded in the IP address list.

9. The method as described in claim 6, further comprising:

giving a default private IP address to the modem if there is no reply from the modem responding to the ARP packets.

10. The method as described in claim 6, wherein the plurality of IP addresses recorded in the IP address list comprise:

192.168.1.1, 192.168.2.1, 192.168.1.254, 10.0.0.1, and 172.16.254.1.

11. A non-transitory storage medium having stored thereon instructions that, when executed by a processor, cause the processor to perform a method for configuring IP addresses of a router, wherein the method comprises:

broadcasting a dynamic host configuration protocol (DHCP) discover packet over a network;

receiving a DHCP offer packet from the modem, wherein the DHCP offer packet comprises a private IP address of the modem;

obtaining the private IP address of the modem from the DHCP offer packet;

configuring IP addresses of a WAN port and a LAN port of the router according to the private IP address of the modem, so as to allow the private IP address of the modem to be in the same network segment with the IP address of the WAN port but in different network segments with the IP address of the LAN port;

storing an IP addresses list that records a plurality of IP addresses into a storage system of the router;

determining whether a broadcast count of broadcasting the DHCP discover packet equals to a predetermined value upon the condition that there is no reply from the modem responding to the DHCP discover packet;

returning to the broadcasting upon the condition that the broadcast count is less than the predetermined value;

acquiring the IP address list from the storage system upon the condition that the broadcast count equals to the predetermined value;

broadcasting a plurality of address resolution protocol (ARP) packets via the network; and

locating the private IP address of the modem according to one of the ARP packets which is responded by the modem.

12. The non-transitory storage medium as described in claim 11, wherein the DHCP discover packet comprises a source address 0.0.0.0, a destination address 255.255.255.255, and a media access control (MAC) address of the router.

13. The non-transitory storage medium as described in claim 11, wherein each of the ARP packets includes one IP address recorded in the IP address list.

14. The non-transitory storage medium as described in claim 11, further comprising:

giving a default private IP address to the modem if there is no reply from the modem responding to the ARP packets.

15. The non-transitory storage medium as described in claim 11, wherein the plurality of IP addresses recorded in the IP address list comprise:

192.168.1.1, 192.168.2.1, 192.168.1.254, 10.0.0.1, and 172.16.254.1.