Route selection in a network

• US 20070230369A1
• Filed: 03/31/2006
• Published: 10/04/2007
• Est. Priority Date: 03/31/2006
• Status: Abandoned Application

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: McAlpine, Gary
• Application Number:
  US11/395,011
• Publication Number:
  US 20070230369A1
• Time in Patent Office: Days
• US Class Current: 370/256
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/26 Route discovery packet
• CPC Class Codes: H04L 45/48 Routing tree calculation
• CPC Class Codes: H04L 45/80 Ingress point selection by the source endpoint, e.g. selection of ISP or POP

Abstract

An input port of a switch in a network receives a discover packet specifying an address of an endpoint in the network, selects one of a spanning-tree-protocol (STP) route or an alternate route from the switch to the endpoint, and forwards the discover packet to an output port of the switch corresponding to the selected route.

Claims

1. A method comprising:

receiving at a first port of a switch in a network a discover packet specifying an address of an endpoint in the network;

selecting one of a spanning-tree-protocol (STP) route or an alternate route from the switch to the endpoint; and

forwarding the discover packet to a second port of the switch corresponding to the selected route.

2. The method of claim 1, further comprising updating an entry in a data structure in the switch for the address specified in the discover packet to indicate the second port of the switch corresponding to the selected route.

3. The method of claim 1, wherein the discover packet is a unicast layer two control protocol packet.

4. The method of claim 1, wherein the address of the endpoint is a destination Media Access Control (MAC) address.

5. The method of claim 1, wherein the alternate route is a redundant route to the endpoint.

6. The method of claim 5, wherein the redundant route is a blocked STP route.

7. The method of claim 1, wherein selecting one of the STP route or alternate route comprises selecting one of the STP route or alternate route according to a load-balancing algorithm.

8. The method of claim 1, wherein selecting the route comprises selecting the route with a lowest cost to the endpoint.

9. The method of claim 8, wherein the cost of a route is a function of the number of paths assigned to the route.

10. The method of claim 8, wherein the cost of a route is a function of whether the route is also a route from the switch to one or more other endpoints in the network.

11. The method of claim 1, wherein selecting a route comprises selecting the route having the shortest path to the endpoint.

12. The method of claim 11, wherein the shortest path is based on a hop count from the switch to the endpoint.

13. The method of claim 1, wherein the discover packet further specifies an address of a second endpoint in the network, the method further comprising:

updating an entry in a data structure in the switch for the second endpoint'"'"'s address to indicate the first port of the switch corresponds to a route from the switch to the second endpoint.

14. The method of claim 1, wherein the second endpoint is a source endpoint in the network.

15. The method of claim 1, further comprising:

receiving at the first port of the switch a broadcast discover packet (BDP) specifying an address of an endpoint that transmitted the BDP;

updating the BDP with identifying information for the switch; and

forwarding the BDP out all ports of the switch.

16. The method of claim 15, further comprising creating or updating an entry in a data structure in the switch for the address of the endpoint that transmitted the BDP to indicate the first port on which the BDP was received.

17. The method of claim 16, wherein the entry further to indicate whether the first port corresponds to the STP route or the alternate route.

18. An article of manufacture, comprising:

an electronically accessible medium including instructions that when executed by a switch in a network cause the switch to;

receive at a first port of the switch a unicast discover packet (UDP) specifying a destination address of an endpoint in the network;

select one of an open spanning-tree-protocol (STP) route or a blocked STP route from the switch to the endpoint;

forward the UDP to a second port of the switch corresponding to the selected route; and

update an entry in a data structure in the switch for the destination address specified in the UDP to indicate the second port of the switch corresponding to the selected route.

19. The article of manufacture of claim 18, wherein the electronically accessible medium further includes instructions that cause the switch to select the one route according to a load-balancing algorithm.

20. The article of manufacture of claim 18, wherein the electronically accessible medium further includes instructions that cause the switch to select the one route according to a lowest cost to the endpoint.

21. A system, comprising:

an Ethernet-based storage area network comprising a plurality of switches, each switch to receive via an electronically accessible medium instructions that when executed by the switch in Ethernet-based storage area network cause the switch to;

receive at a first port of the switch a unicast discover packet (UDP) specifying a destination address of an endpoint in the network;

select one of an open spanning-tree-protocol (STP) route or a blocked STP route from the switch to the endpoint;

forward the UDP to a second port of the switch corresponding to the selected route; and

update an entry in a data structure in the switch for the destination address specified in the UDP to indicate the second port of the switch corresponding to the selected route.

22. The system of claim 21, wherein the electronically accessible medium further includes instructions that cause the switch to select the one route according to a load-balancing algorithm.

23. The system of claim 21, wherein the electronically accessible medium further includes instructions that cause the switch to select the one route according to a lowest cost to the endpoint.