Method and system for scaling network traffic managers

• US 7,102,996 B1
• Filed: 04/09/2002
• Issued: 09/05/2006
• Est. Priority Date: 05/24/2001
• Status: Active Grant

• Current Assignee: F5 Networks, Inc. (F5 Incorporated)
• Original Assignee: F5 Networks, Inc. (F5 Incorporated)
• Inventors: Schmitt, David D., Szabo, Paul I., Masters, Richard Roderick, Amdahl, Carlton G., Gilde, Robert George
• Primary Examiner(s): Patel, Ajit
• Application Number:
  US10/119,433
• Time in Patent Office: 1,610 Days
• Field of Search: 370/351, 370/352, 370/389, 370/401, 370/402, 370/403, 370/229, 370/230, 370/231, 370/232, 370/233, 370/234, 370/235, 370/236, 370/444, 370/445, 370/468, 370/345.1
• US Class Current: 370/230
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/125 by balancing the load, e.g. traffic engineering
• CPC Class Codes: H04L 47/2441 relying on flow classification, e.g. using integrated services [IntServ]

Abstract

A method and system for distributing network traffic to multiple traffic management devices. A distributor receives each packet from a network and may act as a layer 2 switch, a router, or distribute the packet to one of a group of traffic management devices. The distributor may receive packets from servers that the traffic management devices are managing communications to. When distributing packets to traffic management devices, information such as source and destination addresses may be used to determine which traffic management device each packet should be sent to. The distributor causes packets that are part of a flow to be delivered to the same traffic management device. Many configurations are possible for connecting the distributor to the traffic management devices, including connecting each traffic management device to a physical or virtual port on the distributor, connecting the traffic management devices to the distributor using a virtual local area network, and connecting the traffic management devices to a layer 2 switch.

Claims

1. A method for distributing flows of packets over a network having a plurality of network devices and a plurality of traffic managers, comprising:

(a) receiving packets, each packet to be forwarded to one of the plurality of network devices through an intermediate traffic manager;

(b) if the packet includes a source address that is associated with a first set of addresses, forwarding the packet to a first traffic manager that is selected using a destination address of the packet, and

(c) if the packet includes a destination address that is associated with a second set of addresses, forwarding the packet to a second traffic manager that is selected using a source address of the packet,

wherein the first traffic manager and the second traffic manager are the same for each packet in a flow between two network devices.

2. The method of claim 1, wherein using the source address of the packet includes hashing it to obtain a value that is then used to distribute the packet to the first traffic manager.

3. The method of claim 1, wherein using the destination address of the packet includes hashing it to obtain a value that is then used to forward the packet.

4. The method of claim 1, further comprising routing when processing is inapplicable by any one of the plurality of traffic managers.

5. The method of claim 4, wherein processing is inapplicable when the source and destination addresses are unknown by any one of the plurality of traffic managers.

6. The method of claim 5, wherein the source address is unknown when it is not associated with the first set of addresses and wherein the destination address is unknown when it is not associated with the second set of addresses.

7. The method of claim 6, wherein each address includes at least one of a media access control address, a virtual local area network (VLAN) identifier, a transmission control protocol (TCP) port, a user datagram protocol (UDP) port, an internet protocol (IP) address, physical port identifier, and a physical port.

8. The method of claim 1, further comprising replacing a first address with a second address when a packet is received from one of the plurality of traffic managers.

9. The method of claim 8, wherein the first address and the second address are physical addresses.

10. The method of claim 9 wherein the first address is a source media access control (MAC) address.

11. The method of claim 10, wherein the second address is a MAC address associated with a set of traffic managers.

12. A distributor for distributing flows of packets over a network having a plurality of traffic managers, comprising:

(a) a network interface that receives a packet to forward to a device coupled to the distributor; and

(b) coupled to the network interface, at least one processor configured to perform actions, comprising;

(i) when the packet includes a source address that is associated with a first set of addresses, forwarding the packet to a first traffic manager that is selected using a destination address of the packet, and

(ii) when the packet includes a destination address that is associated with a second set of addresses, forwarding the packet to a second traffic manager that is selected using a source address of the packet,

wherein the first traffic manager and the second traffic manager are the same for each packet in a flow between two network devices.

13. The system of claim 12, wherein using the source address of the packet includes hashing it to obtain a value that is then used to distribute the packet to the first traffic manager.

14. The system of claim 12, wherein when the source address is not associated with the first set of addresses and destination address is not associated with the second set of addresses, the at least one processor is configured to performs further actions, comprising routing the packet.

15. The system of claim 14, wherein each address includes at least one of a media access control (MAC) address, a virtual local area network (VLAN) identifier, a transmission control protocol (TCP) port, a user datagram protocol (UDP) port, an internet protocol (IP) address, physical port identifier, and a physical port.

16. The system of claim 12, wherein when the packet is received from one of the plurality of traffic managers, the at least one processor is configured to perform further actions, comprising replacing a first address with a second address.

17. The system of claim 12, wherein the at least one processor includes at least one of a microprocessor, an application specific integrated chip, digital logic, and software.

18. A switch chassis for distributing flows of packet of a network having a plurality of network devices, comprising:

(a) a plurality of distributors that perform actions, including;

(i) receiving a packet to forward to one of the plurality of network devices;

(ii) if the packet includes a source address that is associated with a first set of addresses, forwarding the packet to a first traffic manager that is selected employing a destination address of the packet, and

(iii) if the packet includes a destination address that is associated with a second set of addresses, forwarding the packet to a second traffic manager that is selected employing a source address of the packet,

(b) at least one network interface associated with each of the distributors;

(b) a plurality of traffic managers;

(c) a switch fabric that provides a communication path between the traffic managers and the distributors; and

(d) a set of configuration parameters that is shared by the plurality of distributors,

wherein the first traffic manager and the second traffic manager are the same for each packet in a flow between two network devices.

19. A computer-readable medium having computer-executable instructions for distributing flows of packets over a network including a plurality of network devices and a plurality of traffic managers, comprising:

(a) receiving packets, each packet to be forwarded to one of the plurality of network devices through an intermediate traffic manager;

(b) if the packet includes a source address that is associated with a first set of addresses, forwarding the packet to a first traffic manager that is selected using a destination address of the packet, and

(c) if the packet includes a destination address that is associated with a second set of addresses, forwarding the packet to a second traffic manager that is selected using a source address of the packet,

wherein the first traffic manager and the second traffic manager are the same for each packet in a flow between two devices.

20. A system for distributing flows of communication, wherein a flow of communication includes a sequence of related packets, comprising:

(a) a plurality of servers configured to respond to packets of information;

(b) a plurality of traffic managers configured to direct packets to the plurality of servers;

(c) a distributor that is coupled to the plurality of servers and the plurality of traffic managers, wherein the distributor is structured to receive each packet and forwards a packet to one of the plurality of traffic managers, wherein each packet includes a source address and a destination address, wherein the distributor is configured to perform actions, including;

(i) if the packet includes a source address that is associated with a first set of addresses, forwarding the packet to a first traffic manager that is selected using a destination address of the packet, wherein the first traffic manager chooses a server to receive the packet, and

(ii) if the packet includes a destination address that is associated with a second set of addresses, forwarding the packet to a second traffic manager that is selected using a source address of the packet, wherein the second traffic manager chooses a server to receive the packet,

wherein the first traffic manager and the second traffic manager are the same for each packet in a flow between two devices.

21. The system of claim 20, further comprising a virtual local area network (VLAN) coupled to the traffic managers, wherein the packet is forwarded by placing an identifier in a front of a media access control header and sending the packet to the VLAN switch.

22. The system of claim 20, wherein the distributor is connected to a first traffic manager of the plurality of traffic managers through a port on the distributor, and wherein the first traffic manager is configured to direct each packet it receives from the port to one of the plurality of servers.

23. A method of distributing flows of packets in a network with a plurality of traffic managers, comprising:

(a) receiving a packet;

(b) when the packet is received from a traffic manager, performing actions, including;

(i) changing a first media access control (MAC) address of the packet to a second MAC address that is associated with at least one traffic manager; and

(ii) forwarding the packet towards its destination; and

(c) when the packet is received from a non-traffic manager facility, performing other actions, including;

(i) performing a lookup on at least one of a source address and a destination address;

(ii) when the destination address is located by the lookup, sending the packet to a first traffic manager using the source address;

(iii) when the source address is located by the lookup, sending the packet to a second traffic manager using the destination address;

else

(iv) routing the packet towards its destination.

24. The method of claim 23, wherein the first traffic manager and the second traffic manager are the same for each packet in a flow between two network devices.

25. The method of claim 23, wherein the first address and the second address are each at least one of a media access control (MAC) address, virtual local area network (VLAN) identifier, a transmission control protocol (TCP) port, a user datagram protocol (UDP) port, an internet protocol (IP) address, and a physical port.

26. The method of claim 23, wherein using the source address to send the packet includes performing a hash on the source address.

27. The method of claim 23, wherein using the destination address to send the packet includes performing a hash on the destination address.

28. The method of claim 23, further comprising when the destination address is associated with a Web site and is untranslated, hashing on the source address to obtain a value and sending the packet to a traffic manager associated with the value, wherein the destination address is untranslated when a table indicates that the traffic manager would not have performed network address translation on a source address of another packet to which the packet is a response.

29. The method of claim 23, further comprising when the source address is located by the lookup and the destination address is either translated or translated and associated with a Web site, sending the packet to the destination address.

30. A method of distributing flows of packets in a network with a plurality of traffic managers, comprising:

(a) receiving a packet including a source address and a destination address;

(b) if the packet is received from one of the plurality of traffic managers, forwarding the packet towards its destination;

(c) otherwise, performing actions, including;

(i) searching a table for an action to perform depending on attributes of the source address of the packet and the destination address of the packet; and

(ii) when the action is located in the table, performing the action, including at least one of;

sending the packet to the destination address;

hashing on the source address to obtain a first value and sending the packet to a first traffic manager associated with the value;

hashing on the destination address to obtain a second value and sending the packet to a second traffic manager associated with the second value; and

routing the packet towards its destination,

wherein the first traffic manager and the second traffic manager are the same for each packet in a flow between two network devices.

31. The method of claim 30, wherein the performing the actions, further includes when the destination address corresponds to a source address that was translated by a traffic manager, sending the packet to the destination address.

32. The method of claim 31, further comprising performing a lookup in another table that includes addresses associated with translated addresses, wherein when the destination address is located in the other table, the destination address is determined to correspond to a translated source address.

33. An apparatus for distributing flows of packets in a network having a plurality of network devices and a plurality of traffic managers, comprising:

(a) an interface that receives packets, each packet to be forwarded to one of the plurality of network devices through an intermediate traffic manager;

(b) coupled to the interface, a mechanism that forwards each packet, wherein the forwarding mechanism performs actions, including;

(i) if the packet includes a source address that is associated with a first set of addresses, forwarding the packet to a first traffic manager that is selected using a destination address of the packet, and

(ii) if the packet includes a destination address that is associated with a second set of addresses, forwarding the packet to a second traffic manager that is selected using a source address of the packet,

wherein the first traffic manager and the second traffic manager are the same for each packet in a flow between two network devices.