Load balancing using IPv6 mobility features

• US 7,650,427 B1
• Filed: 06/01/2005
• Issued: 01/19/2010
• Est. Priority Date: 10/29/2004
• Status: Active Grant

• Current Assignee: Akamai Technologies, Inc.
• Original Assignee: Akamai Technologies, Inc.
• Inventors: Liu, Zaide, Swildens, Eric Sven-Johan, Day, Richard David
• Primary Examiner(s): Won; Michael
• Application Number:
  US11/143,872
• Time in Patent Office: 1,693 Days
• Field of Search: 709/203, 709/238, 709/239, 709/240, 709/241, 709/244, 709/242, 709/243, 709/227, 709/230, 370/237, 370/351, 370/392, 370/395.32, 370/251
• US Class Current: 709/238
• CPC Class Codes: H04L 2463/101 applying security measures for digital rights management data processing systems or methods, specially adapted for commerce, e.g. marketing, shopping, billing, auctions or e-commerce G06Q30/00
• CPC Class Codes: H04L 63/102 Entity profiles
• CPC Class Codes: H04L 63/12 Applying verification of the received information cryptographic mechanisms or cryptographic arrangements for data integrity or data verification H04L9/32

Abstract

Techniques are provided for using the mobility support features of IPv6 to allow client and server nodes to communicate without the continuing intervention of a load-balancing node that selected the server node. A load-balancing node intercepts a TCP SYN packet addressed to a virtual IP address. The load-balancing node selects a server node from among multiple server nodes, and sends the packet toward the server node. The server node sends an IPv6 packet toward the client node. The packet contains a Binding Update option that specifies the virtual IP address as a Home Address. This information causes the client node to replace destination addresses in outgoing IP packets so that packets that the client node would have sent toward the virtual IP address are sent toward the selected server node'"'"'s IP address instead. Consequently, the IP packets are routed toward the selected server node instead of the load-balancing node.

Claims

1. A machine-implemented method for enabling communication between nodes, the method comprising the steps of:

receiving a handshake phase initiation request that originated from a particular client node and was intercepted by a load-balancing node; and

engaging in a handshake phase with the particular client node using IPv6 mobility features to allow communication with the particular client node without further intervention by the load-balancing node;

wherein receiving the handshake phase initiation request comprises receiving, at a server node that is associated with a first Internet Protocol (IP) address, a first IP packet that contains a second IP packet that;

(a) indicates, as a destination IP address, a second IP address that differs from the first IP address,

(b) indicates, as a source IP address, a third IP address, and

(c) contains a Transmission Control Protocol (TCP) SYN packet; and

wherein engaging in the handshake phase comprises sending, toward the particular client node that is associated with the third IP address, a third IP packet that;

(a) contains a TCP SYN/ACK packet, and

(b) contains an IPv6 Mobility Header that contains a Binding Update option;

wherein the Binding Update option indicates, in a Lifetime field, a value that is greater than zero;

wherein the presence of the value in the Lifetime field causes the client node to establish a cache entry comprising the first IP address and the second IP address locally within an IP layer cache;

wherein the cache entry remains in the IP layer cache for a period of time commensurate with the value indicated in the Lifetime field;

wherein the second IP address is a virtual IP address that is associated with a server cluster of a plurality of nodes that includes the server node.

2. The method of claim 1, wherein the first IP packet indicates, as a source IP address, a fourth IP address that differs from the third IP address.

3. The method of claim 1, further comprising:

receiving an IPv6 packet that;

(a) indicates the third IP address as a source IP address, and

(b) contains an IPv6 type 2 header that indicates the second IP address in a Home Address field.

4. The machine-implemented method of claim 1, further comprising the step of:

the client node performing a destination IP address replacement operation on the first IP packet, causing the first IP packet to have, as the destination IP address, the second IP address.

5. An apparatus for enabling communication between nodes, the apparatus comprising:

a receiver that receives a handshake phase initiation request that originated from a particular client node and was intercepted by a load-balancing node; and

a module that engages in a handshake phase with the particular node using IPv6 mobility features to allow communication with the particular client node without further intervention by the load-balancing node;

wherein the receiver receives, at a server node that is associated with a first Internet Protocol (IP) address, a first IP packet that contains a second IP packet that;

(a) indicates, as a destination IP address, a second IP address that differs from the first IP address,

(b) indicates, as a source IP address, a third IP address, and

(c) contains a Transmission Control Protocol (TCP) SYN packet; and

wherein the module sends, toward the particular client node that is associated with the third IP address, a third IP packet that;

(a) contains a TCP SYN/ACK packet, and

(b) contains an IPv6 Mobility Header that contains a Binding Update option;

wherein the Binding Update option indicates, in a Lifetime field, a value that is greater than zero;

wherein the presence of the value in the Lifetime field causes the client node to establish a cache entry comprising the first IP address and the second IP address locally within an IP layer cache;

wherein the cache entry remains in the IP layer cache for a period of time commensurate with the value indicated in the Lifetime field;

wherein the second IP address is a virtual IP address that is associated with a server cluster of a plurality of nodes that includes the server node.

6. The apparatus of claim 5, wherein the first IP packet indicates, as a source IP address, a fourth IP address that differs from the third IP address.

7. The apparatus of claim 5, further comprising:

a receiver that receives an IPv6 packet that;

(a) indicates the third IP address as a source IP address, and

(b) contains an IPv6 type 2 header that indicates the second IP address in a Home Address field.

8. The apparatus of claim 5, further comprising:

a replacer in the client node for performing a destination IP address replacement operation on the first IP packet, causing the first IP packet to have, as the destination IP address, the second IP address.

9. A volatile or non-volatile machine-readable storage medium on which is encoded one or more sequences of machine-readable code instructions for enabling communication between nodes, wherein execution of the one or more sequences of instructions by one or more processors causes the one or more processors to perform steps comprising:

receiving a handshake phase initiation request that originated from a particular client node and was intercepted by a load-balancing node; and

engaging in a handshake phase with the particular client node using IPv6 mobility features to allow communication with the particular client node without further intervention by the load-balancing node;

wherein receiving the handshake phase initiation request comprises receiving, at a server node that is associated with a first Internet Protocol (IP) address, a first IP packet that contains a second IP packet that;

(a) indicates, as a destination IP address, a second IP address that differs from the first IP address,

(b) indicates, as a source IP address, a third IP address, and

(c) contains a Transmission Control Protocol (TCP) SYN packet; and

engaging in the handshake phase comprises sending, toward the particular client node that is associated with the third IP address, a third IP packet that;

(a) contains a TCP SYN/ACK packet, and

(b) contains an IPv6 Mobility Header that contains a Binding Update option;

wherein the Binding Update option indicates, in a Lifetime field, a value that is greater than zero;

wherein the presence of the value in the Lifetime field causes the client node to establish a cache entry comprising the first IP address and the second IP address locally within an IP layer cache,

wherein the cache entry remains in the IP layer cache for a period of time commensurate with the value indicated in the Lifetime field;

wherein the second IP address is a virtual IP address that is associated with a server cluster of a plurality of nodes that includes the server node.

10. The machine-readable medium of claim 9, wherein the first IP packet indicates, as a source IP address, a fourth IP address that differs from the third IP address.

11. The machine-readable medium of claim 9, wherein the steps further comprise:

receiving an IPv6 packet that;

(a) indicates the third IP address as a source IP address, and

(b) contains an IPv6 type 2 header that indicates the second IP address in a Home Address field.

12. The machine-readable medium of claim 9, wherein the steps further comprise:

the client node performing a destination IP address replacement operation on the first IP packet, causing the first IP packet to have, as the destination IP address, the second IP address.