System and method for providing persistent connections based on subnet natural class

• US 7,225,237 B1
• Filed: 07/31/2000
• Issued: 05/29/2007
• Est. Priority Date: 07/31/2000
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Tenereillo, Peter
• Primary Examiner(s): Pwu; Jeffrey
• Assistant Examiner(s): BOUTAH, ALINA A
• Application Number:
  US09/629,036
• Time in Patent Office: 2,493 Days
• Field of Search: 709217-219, 709/225, 709/203, 709/238, 709/223, 370/392, 718/105
• US Class Current: 709/219
• 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 67/1008 based on parameters of servers, e.g. available memory or workload monitoring of computer activity G06F11/30
• CPC Class Codes: H04L 67/1017 based on a round robin mechanism
• CPC Class Codes: H04L 67/1027 Persistence of sessions during load balancing
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 67/563 Data redirection of data network streams

Abstract

A method for providing a persistent connection between a client and a real server. The method includes receiving a request originating from a client for connection to a virtual server and selecting a real server associated with the virtual server for connection with the client based only on a natural class of an IP address of a device sending the request. Transmissions originating from the client are forwarded to the selected real server.

Claims

1. A method for providing a persistent connection between a client and a real server, the method comprising:

providing a local director in communication with a plurality of clients and two or more real servers, said plurality of clients configured for communication with said two or more real servers through said local director;

receiving at said local director a request originating from a first client of said plurality of clients for connection to a virtual server implemented on the local director;

identifying a natural class of an IP address of said first client;

determining if the local director has received and sent out connection requests from any client of said plurality of clients, having the same natural class as said first client by searching a table stored on the local director and identifying previous connections created between the local director and said two or more real servers;

if the local director has received and sent out a connection request to one of said real servers from any client having the same natural class as said first client, selecting the same real server for connection with said first client,

wherein selecting a real server comprises selecting the same real server for all clients having the same natural class subnet;

if the local director has not received and sent out a connection request to one of said real servers from any client having the same natural class as said first client, selecting one of said real servers based on load balancing; and

forwarding to the selected real server transmissions originating from said first client;

wherein receiving a request comprises receiving a request from a firewall and wherein the IP address of a device sending the request is the IP address of the firewall.

2. The method of claim 1 wherein the request is an HTTP request.

5. The method of claim 1 further comprising updating said table each time a connection is made between the local director and said two or more real servers with a new natural class.

6. The method of claim 1 wherein identifying a natural class comprises identifying a subnet mask and wherein the selection of the real server is based on the identified subnet mask.

7. The method of claim 1 further comprising updating entries in said local director table when a connection is made with a new natural class.

3. A computer program product for providing a persistent connection between a client and a server, the client configured for communication with two or more real servers through a local director, the product comprising:

code that receives a request at said local director originating from a first client for connection to a virtual server implemented on the local director;

code that identifies a natural class of an IP address of said first client;

code that determines if the local director has received and sent out connection requests from any client of said plurality of clients, having the same natural class as said first client by searching a table stored on the local director and identifying previous connections created between the local director and said two or more real servers;

if the local director has received and sent out a connection request to one of said real servers from any client having the same natural class as said first client, code that selects the same real server for connection with said first client, wherein the code that selects a real server comprises code that selects the same real server for all clients having the same natural class subnet;

code that selects one of said real servers based on load balancing if the local director has not received and sent out a connection request to one of said real servers from any client having the same natural class as said first client; and

code that forwards to the selected real server transmission originating from said first client, wherein the code that receives a request comprises code that receives a request from a firewall and wherein the IP address of a device sending the request is the IP address of the firewall; and

a computer-readable storage medium for storing the codes.

4. The computer program product of claim 3 wherein the computer-readable medium is selected from a group consisting of CD-ROM, floppy disk, tape, flash memory, system memory, and hard drive.

8. A system for providing a persistent connection between a client and a real server, the client configured for communication with two or more real servers through a local director, the method comprising:

means for receiving at said local director a request originating from a first client for connection to a virtual server implemented on the local director, the local director in communication with two or more real servers,

means for identifying a natural class of an IP address of said first client;

means for determining if the local director has received and sent out connection requests from any client of said plurality of clients, having the same natural class as said first client by searching a table stored on the local director and identifying previous connections created between the local director and said two or more real servers;

if the local director has received and sent out a connection request to one of said real servers from said any client having the same natural class as said first client, selecting the same real server for connection with said first client;

if the local director has not received and sent out a connection request to one of said real servers from any client having the same natural class as said first client, selecting one of said real servers based on load balancing, wherein selecting a real server comprises selecting the same real server for all clients having the same natural class subnet; and

means for forwarding to the selected real server transmissions originating from said first client;

wherein means for receiving a request comprises means for receiving a request from a firewall and wherein the IP address of a device sending the request is the IP address of the firewall.

9. The system of claim 8 wherein means for selecting a real sever for connecting with the client comprises selecting the same real server for requests received from IP addresses having the same natural class subnet.