Network address translation using a forwarding agent

• US 6,650,641 B1
• Filed: 07/02/1999
• Issued: 11/18/2003
• Est. Priority Date: 07/02/1999
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Albert, Mark, Tiwari, Pranav Kumar, Menditto, Louis F., Howes, Richard A., Tsang, Tzu-Ming, LeBlanc, William M., Jordan, James A., Kersey, Edward A., McGuire, Jacob Mark, OʼRourke, Chris
• Primary Examiner(s): Rao, Seema S.
• Assistant Examiner(s): ABELSON, RONALD B
• Application Number:
  US09/347,109
• Time in Patent Office: 1,600 Days
• Field of Search: 370/466-467, 370/389, 370/392, 370/397, 370/401, 709/245
• US Class Current: 370/392
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/2514 between local and global IP addresses
• CPC Class Codes: H04L 61/2557 Translation policies or rules
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/10015 Access to distributed or replicated servers, e.g. using brokers

Abstract

A system and method are disclosed for specifying network address translation for a set of packets. A first set of instructions is sent to a forwarding agent specifying criteria for designated packets that are designated to undergo network address translation. A matching packet is received from the forwarding agent that matches the specified criteria. A network address translation scheme is determined for the matching packet. A second set of instructions are sent specifying the network address translation scheme for packets associated with the matching packet.

Claims

1. A method of specifying network address translations for a set of packets including:

sending a first set of instructions to a forwarding agent specifying criteria for designated packets that are designated to undergo network address translation;

receiving from the forwarding agent a matching packet that matches the specified criteria;

determining a network address translation scheme for the matching packet; and

sending a second set of instructions specifying the network address translation scheme for packets associated with the matching packet;

wherein the matching packet is an initial packet for a new flow and the packets associated with the matching packet are packets associated with the new flow; and

wherein sending a first set of instructions to a forwarding agent specifying criteria for designated packets that are designated to undergo network address translation includes specifying to the forwarding agent that in order to accept the first set of instructions, the forwarding agent can support network address translation.

2. The method of specifying network address translations for a set of packets as recited in claim 1, further including receiving selected packets associated with the connection and monitoring the status of the connection.

3. The method of specifying network address translations for a set of packets as recited in claim 1, wherein the network address translation scheme includes translating a source IP address of packets associated with the matching packet.

4. The method of specifying network address translations for a set of packets as recited in claim 1, wherein the network address translation scheme includes translating a source port number of packets associated with the matching packet.

5. The method of specifying network address translations for a set of packets as recited in claim 1, wherein the network address translation scheme includes translating a destination IP address of packets associated with the matching packet.

6. The method of specifying network address translations for a set of packets as recited in claim 1, wherein the network address translation scheme includes translating a destination port number of packets associated with the matching packet.

7. The method of specifying network address translations for a set of packets as recited in claim 1, wherein determining a network address translation scheme for the matching packet includes load balancing connections among a set of hosts having individual real IP addresses and selecting one of the individual real IP addresses as a destination IP address for the packets associated with the matching packet.

8. A method of performing network address translation based on instructions received from a service manager comprising:

receiving a first set of instructions from a service manager specifying criteria for designated packets that are designated to undergo network address translation;

sending to the service manager a matching packet that matches the specified criteria;

receiving a second set of instructions specifying the network address translation scheme for packets associated with the matching packet;

receiving a packet associated with the matching packet; and

performing network address translation according to the network address translation scheme on the packet associated with the matching packet;

wherein the matching packet is a SYN packet for a new connection and the packets associated with the matching packet are packets associated with the new connection.

9. A method of specifying a network address translation for a set of packets as recited in claim 8 further including sending selected packets associated with the connection to the service manager.

10. A method of specifying a network address translation for a set of packets as recited in claim 8 wherein the network address translation scheme includes translating a source IP address of packets associated with the matching packet.

11. A method of specifying a network address translation for a set of packets as recited in claim 8 wherein the network address translation scheme includes translating a source port number of packets associated with the matching packet.

12. A method of specifying a network address translation for a set of packets as recited in claim 8 wherein the network address translation scheme includes translating a destination IP address of packets associated with the matching packet.

13. A method specifying a network address translation for a set of packets as recited in claim 8 wherein the network address translation scheme includes translating a destination port number of packets associated with the matching packet.

14. A computer program product for specifying network address translation for a set of packets, the computer program product being embodied in a computer readable medium and comprising computer instructions for:

sending a first set of instructions to a forwarding agent specifying criteria for designated packets that are designated to undergo network address translation;

receiving from the forwarding agent a matching packet that matches the specified criteria;

determining a network address translation scheme for the matching packet; and

sending a second set of instructions specifying the network address translation scheme for packets associated with the matching packet;

wherein the matching packet is a SYN packet for a new connection and the packets associated with the matching packet are packets associated with the new connection; and

wherein sending a first set of instructions to a forwarding agent specifying criteria for designated packets that are designated to undergo network address translation includes specifying to the forwarding agent that in order to accept the first set of instructions, the forwarding agent can support network address translation.

15. A system for specifying network address translation for a set of packets including:

means for sending a first set of instructions to a forwarding agent specifying criteria for designated packets that are designated to undergo network address translation

means for receiving from the forwarding agent a matching packet that matches the specified criteria;

means for determining a network address translation scheme for the matching packet; and

means for sending a second set of instructions specifying the network address translation scheme for packets associated with the matching packet;

wherein the matching packet is a SYN packet for a new connection and the packets associated with the matching packet are packets associated with the new connection; and

wherein the means for sending a first set of instructions to a forwarding agent specifying criteria for designated packets that are designated to undergo network address translation include means for specifying to the forwarding agent that in order to accept the first set of instructions, the forwarding agent can support network address translation.

16. A system for performing network address translation based on instructions received from a service manager comprising:

means for receiving a first set of instructions from a service manager specifying criteria for designated packets that are designated to undergo network address translation;

means for sending to the service manager a matching packet that matches the specified criteria;

means for receiving a second set of instructions specifying the network address translation scheme for packets associated with the matching packet;

means for receiving a packet associated with the matching packet; and

means for performing network address translation according to the network address translation scheme on the packet associated with the matching packet;

wherein the matching packet is a SYN packet for a new connection and the packets associated with the matching packet are packets associated with the new connection.

17. A computer program product for performing network address translation based on instructions received from a service manager, the computer program product being embodied in a computer readable medium and comprising computer instructions for:

receiving a first set of instructions from a service manager specifying criteria for designated packets that are designated to undergo network address translation;

sending to the service manager a matching packet that matches the specified criteria;

receiving a second set of instructions specifying the network address translation scheme for packets associated with the matching packet;

receiving a packet associated with the matching packet; and

performing network address translation according to the network address translation scheme on the packet associated with the matching packet;

wherein the matching packet is a SYN packet for a new connection and the packets associated with the matching packet are packets associated with the new connection.