Technique for improving load balancing of traffic in a data network using source-side related information

• US 7,328,237 B1
• Filed: 07/25/2002
• Issued: 02/05/2008
• Est. Priority Date: 07/25/2002
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Thubert, Pascal, Levy-Abegnoli, Eric
• Primary Examiner(s): Cardone; Jason
• Assistant Examiner(s): HOSSAIN, TANIM M
• Application Number:
  US10/205,669
• Time in Patent Office: 2,021 Days
• Field of Search: 709/224, 709/203, 709/229, 709/238, 709/245, 370/392
• US Class Current: 709/203
• CPC Class Codes: H04L 61/35 involving non-standard use of addresses for implementing network functionalities, e.g. coding subscription information within the address or functional addressing, i.e. assigning an address to a function
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1006 with static server selection, e.g. the same server being selected for a specific client
• CPC Class Codes: H04L 67/1014 based on the content of a request
• CPC Class Codes: H04L 67/306 User profiles
• CPC Class Codes: H04L 67/61 taking into account QoS or priority requirements

Abstract

According to various aspects of the present invention, a technique is described for improving load balancing of traffic in a data network using source-side related information embedded into the destination IP address field of packets received at a load balancing device. One aspect of the present invention relates to assigning more than one virtual IP address to a server cluster in order to enable different clients to select a virtual cluster address which corresponds to each clients'"'"' respective rights and/or profiles, and to use the selected virtual cluster address to access a desired site or service. Another aspect of the present invention relates to a mechanism which allows for load balancing operations to be implemented using source-side information which is embedded into the destination IP address of a packet header. In this way, load balancing decisions may be quickly performed at initial or early stages of a connection flow.

Claims

1. A method of processing incoming packets from a plurality of clients for distribution among a plurality of servers in a data network, the method comprising:

generating a modified destination IP address of a first packet using a virtual IP address received in response to a DNS look-up request, by execution of an IP address modification application at a first client, wherein the modified destination IP address includes embedded source-side information derived using encrypted keys in conjunction with the IP address modification application;

configuring the first client to access one or more specific DNS servers based on rights and privileges of the first client;

receiving a first packet from the first client;

the first packet including a destination Internet Protocol (IP) address field in a header portion of the packet, the destination IP address field having a subfield for embedding source-side information including one or more of user-specific data, user preference data, requested content, first client priority information, and first client privilege information;

analyzing the destination IP address field of the first packet to identify source-side information embedded therein;

selecting, using said identified source-side information, an appropriate server from the plurality of servers; and

forwarding the first packet to the appropriate server.

2. The method of claim 1 wherein the first packet corresponds to a TCP SYN packet.

3. The method of claim 2 further comprising forwarding the TCP SYN packet to a selected server of the plurality of servers.

4. The method of claim 3 wherein the TCP SYN packet is forwarded to a selected server of the plurality of servers without first establishing a TCP connection with the first client.

5. The method of claim 1 wherein the source-side information includes information relating to an identity of the first client.

6. The method of claim 1 wherein the source-side information includes information relating to user specific information.

7. The method of claim 1 wherein the source-side information includes information relating to user preference information.

8. The method of claim 1 wherein the source-side information includes information relating to requested content.

9. The method of claim 1 wherein the source-side information includes session information relating to the first client.

10. The method of claim 1 wherein the source-side information includes Quality of Service (QoS) information relating to the first client.

11. The method of claim 1 wherein the source-side information includes priority information relating to the first client.

12. The method of claim 1 wherein the source-side information includes privilege information relating to the first client.

13. The method of claim 1 further comprising performing Quality of Service (QoS) processing on the first packet using said source-side information.

14. The method of claim 1 wherein the first packet is associated with a first flow;

wherein the destination address field of the first packet includes flow information;

wherein said flow information includes source IP address information, destination IP address information, source TCP port information, and destination TCP port information;

determining, using said flow information, whether any server of the plurality of servers has been associated with the first flow; and

forwarding the first packet to an associated server in response to determining that at least one server of the plurality of servers has been associated with the first flow.

15. The method of claim 1 wherein the destination address field of the first packet includes embedded information relating to at least one aspect of the first client.

16. The method of claim 1 wherein the destination address field of the first packet includes:

a cluster address portion which includes subnet and host address information; and

source-side information relating to at least one aspect of the first client.

17. A computer program product, including a machine-readable medium storing program instructions embodied therein, for implementing the method of claim 1.

18. A method as recited in claim 1 further comprising:

determining that the least significant bits of the destination IP address are not modified.

19. A method as recited in claim 1 wherein the embedded source-side information has a length L in the least significant bits of the modified destination IP address.

20. A system of processing incoming packets from a plurality of clients for distribution among a plurality of servers in a data network, the system comprising:

means for generating a modified destination IP address of a first packet using a virtual IP address received in response to a DNS look-up request, by execution of an IP address modification application at a first client, wherein the modified destination IP address includes embedded source-side information derived using encrypted keys in conjunction with the IP address modification application;

means for configuring the first client to access one or more specific DNS servers based on rights and privileges of the first client;

means for receiving a first packet from the first client;

the first packet, including a destination Internet Protocol (IP) address field in a header portion of the packet the destination IP address field having a sub-field for embedding source-side information including one or more of user-specific data, user preference data, requested content, first client priority information, and first client privilege information;

means for analyzing the destination address field of the first packet to identify source-side information embedded therein;

means for selecting, using said source-side information, an appropriate server from the plurality of servers; and

means for forwarding the first packet to the appropriate server;

wherein the destination address field of the first packet includes;

a cluster address portion which includes subnet and host address information.

21. A system of processing incoming packets from a plurality of clients for distribution among a plurality of servers in a data network, the system comprising:

at least one processor;

at least one interface configured or designed to provide a communication link to at least one other network device in the data network; and

memory;

the system being configured or designed to generate a modified destination IP address of a first packet using a virtual IP address received in response to a DNS look-up request by execution of an IP address modification application at the first client, wherein the modified destination IP address includes embedded source-side information derived using encrypted keys in conjunction with the IP address modification application; and

configured or designed to enable the first client to access one or more specific DNS servers based on rights and privileges of the first client; and

configured or designed to receive a first packet from the first client;

the first packet including a destination Internet Protocol (IP) address field in a header portion of the packet the destination IP address field having a sub-field for embedding source-side information including one or more of user-specific data, user preference data, requested content, first client priority information, and first client privilege information;

the system being further configured or designed to analyze the destination address field of the first packet to identify source-side information embedded therein;

the system being further configured or designed to select, using said identified source-side information, an appropriate server from the plurality of servers; and

the system being further configured or designed to forward the first packet to the appropriate server.

22. The system of claim 21 wherein the first packet corresponds to a TCP SYN packet.

23. The system of claim 22 being further configured or designed to forward the TCP SYN packet to a selected server of the plurality of servers.

24. The system of claim 23 wherein the TCP SYN packet is forwarded to a selected server of the plurality of servers without first establishing a TCP connection with the first client.

25. The system of claim 21 wherein the source-side information includes information relating to an identity of the first client.

26. The system of claim 21 wherein the source-side information includes information relating to user specific information.

27. The system of claim 21 wherein the source-side information includes information relating to user preference information.

28. The system of claim 21 wherein the source-side information includes information relating to requested content.

29. The system of claim 21 wherein the source-side information includes session information relating to the first client.

30. The system of claim 21 wherein the source-side information includes Quality of Service (QoS) information relating to the first client.

31. The system of claim 21 wherein the source-side information includes priority information relating to the first client.

32. The system of claim 21 wherein the source-side information includes privilege information relating to the first client.

33. The system of claim 21 being further configured or designed to perform Quality of Service (QoS) processing on the first packet using said source-side information.

34. The system of claim 21 wherein the first packet is associated with a first flow;

wherein the destination address field of the first packet includes flow information;

wherein said flow information includes source IP address information, destination IP address information, source TCP port information, and destination TCP port information;

the system being further configured or designed to determine, using said flow information, whether any server of the plurality of servers has been associated with the first flow; and

the system being further configured or designed to forward the first packet to an associated server in response to determine that at least one server of the plurality of servers has been associated with the first flow.

35. The system of claim 21 wherein the destination address field of the first packet includes embedded information relating to at least one aspect of the first client.

36. The system of claim 21 wherein the destination address field of the first packet includes:

a cluster address portion which includes subnet and host address information; and

source-side information relating to at least one aspect of the first client.