Load balancing

• US 8,484,374 B2
• Filed: 08/03/2012
• Issued: 07/09/2013
• Est. Priority Date: 07/15/1998
• Status: Expired due to Term

• Current Assignee: Radware Limited
• Original Assignee: Radware Limited
• Inventors: Zisapel, Roy, Peles, Amir, Fuks, Smadar
• Primary Examiner(s): Coulter, Kenneth R
• Application Number:
  US13/566,171
• Publication Number:
  US 20120303784A1
• Time in Patent Office: 340 Days
• Field of Search: 709238-244, 709/245, 718/105, 718/104, 718/102
• US Class Current: 709/241
• CPC Class Codes: G06F 9/505 considering the load
• CPC Class Codes: H04L 45/14 Routing performance; Theoretical aspects
• CPC Class Codes: H04L 47/125 by balancing the load, e.g. traffic engineering
• 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 67/1008 based on parameters of servers, e.g. available memory or workload monitoring of computer activity G06F11/30
• CPC Class Codes: H04L 67/101 based on network conditions
• CPC Class Codes: H04L 67/1012 based on compliance of requirements or conditions with available server resources
• CPC Class Codes: H04L 69/32 Architecture of open systems interconnection [OSI] 7-layer type protocol stacks, e.g. the interfaces between the data link level and the physical level
• CPC Class Codes: H04L 69/325 in the network layer [OSI layer 3], e.g. X.25 H04L69/16 takes precedence

Abstract

A network management system, device and method for managing a computer network. The device is connected to the Internet through a plurality of routes, wherein the plurality of routes are assigned with respective IP addresses. The device includes a controller receiving a DNS resolution query from a remote computer for a domain name within the computer network, selecting one of the plurality of routes connecting the device to the Internet, and responding to the DNS resolution query with an IP address associated with the selected route. The IP address is used for resolution of the domain name.

Claims

1. A method for load balancing client requests among a plurality of internet service provider (ISP) links in a multi-homed network, comprising:

resolving an incoming domain name server (DNS) query for an address associated with a domain name of a server within the multi-homed network, wherein the incoming DNS query is received from a client;

selecting, based on at least one load balancing criterion, one ISP link from the plurality ISP links; and

returning an internet protocol (IP) address selected from a range of IP addresses associated with the selected ISP link, thereby subsequent requests from the client are routed through the selected ISP link.

2. The method of claim 1, wherein the at least one load balancing criterion includes availability of each of the ISP link.

3. The method of claim 1, wherein the at least one load balancing criterion includes any one of a round-robin selection parameter and a random selection parameter.

4. The method of claim 1, wherein the at least one load balancing criterion includes a decision function, wherein the decision function is a weighed function of at least one of a load on each ISP link, packet losses on each ISP link, and a cost of each ISP link.

5. The method of claim 1, wherein the least one load balancing criterion includes a measured proximity between the server and each of the ISP links.

6. The method of claim 1, further comprising:

translating a source IP address of the server to the address of the selected ISP link, thereby responses to the client are routed through the selected ISP link.

7. The method of claim 6, wherein each of the ISP links is connected to a router configured with a range of IP addresses associated with a respective ISP link.

8. A non-transitory computer readable medium having stored thereof computer executable code causing a computer to execute the method of claim 1.

9. A device for load balancing client requests among a plurality of internet service provider (ISP) links in a multi-homed network, comprising:

a network controller configured to resolve an incoming domain name server (DNS) query for an address associated with a domain name of a server within the multi-homed network, wherein the incoming DNS query is received from a client; and

a balancer module configured to select, based on at least one load balancing criterion, one ISP link from the plurality ISP links;

wherein the network controller is further configured to return an internet protocol (IP) address selected from a range of IP addresses associated with the selected ISP link, thereby subsequent requests from the client are routed through the selected ISP link.

10. The device of claim 9, wherein the at least one load balancing criterion includes availability of each of the ISP link.

11. The device of claim 9, wherein the at least one load balancing criterion includes any one of a round-robin selection parameter and a random selection parameter.

12. The device of claim 9, wherein the at least one load balancing criterion includes a decision function, wherein the decision function is a weighed function of at least one of a load on each ISP link, packet losses on each ISP link, and a cost of each ISP link.

13. The device of claim 9, wherein the least one load balancing criterion includes a measured proximity between the server and each of the ISP links.

14. The device of claim 9, wherein the network controller is further configured to translate a source IP address of the server to the address of the selected ISP link, thereby responses to the client are routed through the selected ISP link.

15. The device of claim 14, wherein each of the ISP links is connected to a router configured with a range of IP addresses associated with a respective ISP link.