Method and system for managing addresses for network host interfaces in a data-over-cable system

• US 6,240,464 B1
• Filed: 02/04/1998
• Issued: 05/29/2001
• Est. Priority Date: 02/04/1998
• Status: Expired due to Term

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: 3Com Corporation (HP Inc.)
• Inventors: Beser, Nurettin B., Fijolek, John G.
• Primary Examiner(s): Breene, John
• Assistant Examiner(s): ROBINSON, GRETA LEE
• Application Number:
  US09/018,780
• Time in Patent Office: 1,210 Days
• Field of Search: 707/10, 707/104, 395/200.33, 395/200.38, 395/200.47, 348/5.5, 348/6, 709/220, 709/250, 709/238, 709/218, 713/201, 370/351
• US Class Current: 709/250
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 61/10 of different types
• CPC Class Codes: H04L 61/5014 using dynamic host configuration protocol [DHCP] or bootstrap protocol [BOOTP]
• CPC Class Codes: H04L 61/5053 Lease time; Renewal aspects

Abstract

A method and system for managing addresses of network host interfaces in a data-over-cable system such as Internet Protocol interfaces. The method allows network host interfaces addresses to be removed from routing tables on network devices such as cable modems or customer premise equipment when their lease expires. This helps prevent the data-over-cable system from exhausting available network host interface addresses of the data-over-cable system. In addition, the method helps ensure that transactions are not conducted on a network host interface address in the data-over-cable system unless it has a valid lease in the one or more routing tables on network devices.

Claims

1. In a data-over-cable system including a plurality of network devices, a method of managing network host interface addresses, the method comprising the following steps:

receiving on a first network a first message for a network device with a first network connection address from a selected network host interface available on the first network, wherein the first message includes a lease time for the first network connection address;

storing the first network connection address and the lease time in one or more routing tables in the first network; and

periodically checking the routing tables on the first network to determine if the lease time for the first network connection address has expired, and if so,

sending a second message to the network device indicating that the lease time for the first network connection address has expired, and

determining whether the network device desires to continue to use the first network connection address, and if not,

removing the first network connection address and lease time from the one or more routing tables on the first network.

2. A computer readable medium having stored therein instructions for causing a central processing unit to execute the steps of the method of claim 1.

3. The method of claim 1 further comprising:

determining whether the network device desires to continue to use the first network connection address, and if so,

not removing the first network connection address from the one or more routing tables on the first network.

4. The method of claim 1 wherein the network device is any of a cable modem termination system, a cable modem or customer premise equipment.

5. The method of claim 1 wherein the first message is a Dynamic Host Configuration Protocol acknowledgment message and the second message is a Dynamic Host Configuration Protocol release message.

6. The method of claim 1 wherein the step of determining whether the network device desires to continue to use the first network connection address includes determining with a third message received from the network device in response to the second message whether the network device desires to continue using first network connection address.

7. The method of claim 1 wherein the one or more routing tables include an Address Resolution Protocol table.

8. In a data-over-cable system including a plurality of network devices, a method of managing network host interface addresses, the method comprising the following steps:

receiving on a first network device a first message with a first network connection address from a selected network host interface available on the first network for a second network device, wherein the first message includes a lease time for the first network connection address;

storing the first network connection address and the lease time in one or more routing tables in the first network device; and

periodically checking the routing tables on the first network device to determine if the lease time for the first network connection address has expired, and if so,

sending a second message to the second network device indicating that the lease time for the first network connection address has expired, and

determining if a third message is received within a predetermined amount of time indicating the second network device desires to continue to use the first network connection address, and if not,

removing the first network connection address and lease time from the one or more routing tables on the first network device.

9. A computer readable medium having stored therein instructions for causing a central processing unit to execute the steps of the method of claim 8.

10. The method of claim 8 further comprising:

determining whether the second network device desires to continue to use the first network connection address, and if so,

not removing the first network connection address from the one or more routing tables on the first network device.

11. The method of claim 8 wherein the first network device is a cable modem termination system and the second network device is any of a cable modem or customer premise equipment.

12. The method of claim 8 wherein the first and third messages are a Dynamic Host Configuration Protocol acknowledgment messages and the second message is a Dynamic Host Configuration Protocol release message.

13. The method of claim 8 wherein the one or more routing tables include an Address Resolution Protocol table.

14. The method of claim 8 wherein the selected network host interface is an Internet Protocol host interface.

15. The method of claim 8 wherein the second and third messages are lease expired and renew lease messages and are not Dynamic Host Configuration Protocol messages.

16. The method of claim 8 further comprising:

receiving a request for a second connection address on the first network device;

determining whether the second connection address is stored in the one or more routing tables on the first network device, and if so,

determining whether a lease time for the second connection address has expired, and if so,

rejecting the request for the second connection address.

17. The method of claim 16 further comprising:

determining whether a lease time for the second connection address exists, and if not,

rejecting the request for the second connection address.

18. In a data-over-cable system including a plurality of network devices, a method of managing network host interface addresses, the method comprising the following steps:

receiving on a cable network a first Dynamic Host Configuration Protocol acknowledgment message with a first network connection address from a selected network host interface available on the cable network for a network device, wherein the first Dynamic Host Configuration Protocol acknowledgment message includes a lease time for the first network connection address;

storing the first network connection address and the lease time in one or more routing tables on a cable modem termination system on the cable network; and

periodically checking the routing tables on the cable modem termination system to determine if the lease time for the first network connection address has expired, and if so,

sending a Dynamic Host Configuration Protocol release message to the network device indicating that the lease time for the first network connection address has expired;

determining whether the network device desires to continue to use the first network connection address by waiting a predetermined time for a second Dynamic Host Configuration Protocol acknowledgment message from the network device including the first network connection address; and

if the second Dynamic Host Configuration Protocol acknowledgment message is not received in the predetermined time,

removing the first network connection address and lease time from the one or more routing tables on the cable modem termination system.

19. A computer readable medium having stored therein instructions for causing a central processing unit to execute the method of claim 18.

20. The method of claim 18 wherein the network device is any of a cable modem or customer premise equipment.