Method and apparatus for server load balancing

• US 6,980,550 B1
• Filed: 01/16/2001
• Issued: 12/27/2005
• Est. Priority Date: 01/16/2001
• Status: Active Grant

• Current Assignee: Extreme Networks, Inc.
• Original Assignee: Extreme Networks, Inc.
• Inventors: Rovner, Edward Joel, Lin, Arthur, Saravanan, Desikan, Yip, Michael, Bailey, Brian, Anderson, Paul, Hepting, Tash
• Primary Examiner(s): QURESHI, AFSAR M
• Application Number:
  US09/761,281
• Time in Patent Office: 1,806 Days
• Field of Search: 370/392, 370/395.32, 370/401, 370/400, 370/395.52, 370/409, 370/428, 370/395.5, 370/465, 370/295.32
• US Class Current: 370/392
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/54 Organization of routing tables
• CPC Class Codes: H04L 45/745 Address table lookup; Address filtering
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• 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 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1023 based on a hash applied to IP addresses or costs
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A method for forwarding data packets to one of a plurality of servers comprising receiving a data packet from a source, at a data packet forwarding device having a plurality of ports, performing a hashing function using a unique component of the data packet as a seed value for the hash, generating a hash value using the hashing function, looking up a table for an address of one of the plurality of servers using the hashed value as an index to the table, and forwarding the data packet to a server corresponding to the address.

Claims

1. A method for load balancing among a plurality of servers in a server bank comprising:

receiving a data packet at a packet forwarding device to be forwarded to one of the plurality of servers in the server bank;

performing a hash function using one or more identifiers for the data packet to generate a hash value;

obtaining an address of one of the plurality of servers in the server bank from a server bank table by using the generated hash value as an index value for the address, wherein the server bank table includes an address of each server of the plurality of servers and an index value associated with each address; and

forwarding the data packet to the server in the server bank using the address found in the server bank table.

2. The method of claim 1, wherein performing a hash function using one or more identifiers for the data packet comprises performing a hash function using the data packet'"'"'s Internet Protocol (IP) source address.

3. The method of claim 1, wherein performing a hash function using one or more identifiers for the data packet comprises performing a hash function using the data packet'"'"'s Internet Protocol (IP) destination address.

4. The method of claim 1, wherein performing a hash function using one or more identifiers for the data packet comprises performing a hash function using the data packet'"'"'s Transmission Control Protocol (TCP) source port number.

5. The method of claim 1, wherein performing a hash function using one or more identifiers for the data packet comprises performing a hash function using the data packet'"'"'s Transmission Control Protocol (TCP) destination port number.

6. The method of claim 1, wherein searching a server bank table for an address of one of the plurality of servers in the server bank comprises searching a server bank table for an Internet Protocol (IP) address of one of the plurality of servers in the server bank.

7. The method of claim 1, wherein searching a server bank table for an address of one of the plurality of servers in the server bank comprises searching a server bank table for a Media Access Control (MAC) address of one of the plurality of servers in the server bank.

8. An article of manufacture comprising:

a machine accessible medium including content that when accessed by a machine causes the machine to perform operations comprising;

receiving a data packet at a packet forwarding device to be forwarded to one of the plurality of servers in the server bank;

performing a hash function using one or more identifiers for the data packet to generate a hash value;

obtaining an address of one of the plurality of servers in the server bank from a server bank table by using the generated hash value as an index value for the address, wherein the server bank table includes an address of each server of the plurality of servers and an index value associated with each address; and

forwarding the data packet to the server in the server bank using the address found in the server bank table.

9. The article of manufacture of claim 8, wherein performing a hash function using one or more identifiers for the data packet to generate a hash value comprises performing a hash function using the data packet'"'"'s Internet Protocol (IP) source address.

10. The article of manufacture of claim 8, wherein a machine performing a hash function using one or more identifiers for the data packet to generate a hash value comprises performing a hash function using the data packet'"'"'s Internet Protocol (IP) destination address.

11. The article of manufacture of claim 8, wherein performing a hash function using one or more identifiers for the data packet to generate a hash value comprises performing a hash function using the data packet'"'"'s Transmission Control Protocol (TCP) source port number.

12. The article of manufacture of claim 8, wherein performing a hash function using one or more identifiers for the data packet to generate a hash value comprises performing a hash function using the data packet'"'"'s Transmission Control Protocol (TCP) destination port number.

13. The article of manufacture of claim 8, wherein searching a server bank table for an address of one of the plurality of servers in the server bank comprises searching a server bank table for an Internet Protocol (IP) address of one of the plurality of servers in the server bank.

14. The article of manufacture of claim 8, wherein a machine searching a server bank table for an address of one of the plurality of servers in the server bank comprises searching a server bank table for a Media Access Control (MAC) address of one of the plurality of servers in the server bank.