Method and system for router aggregation

• US 20060039385A1
• Filed: 08/17/2004
• Published: 02/23/2006
• Est. Priority Date: 08/17/2004
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Wakumoto, Shaun Kazuo, Bare, Ballard Claude
• Granted Patent: US 8,009,668 B2
• Time in Patent Office: Days
• US Class Current: 370/400
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• CPC Class Codes: H04L 45/58 Association of routers
• CPC Class Codes: H04L 45/586 of virtual routers

Abstract

One embodiment disclosed relates to a method of routing a packet by way of a router aggregation. A packet is received from outside the aggregation by an initially receiving router/switch unit. Router functions are performed by the initially receiving router unit, including modification of the packet. The packet is then sent to a layer 2 network of the aggregation, wherein switching functions are performed on the packet. Another embodiment disclosed relates to a cooperative aggregation of router/switch units. The aggregation includes a plurality of the router/switch units, and a switching network interconnecting the units. The cooperative aggregation functions as a single router from a perspective of an external network device coupled to the system.

Claims

1. A cooperative aggregation of router/switch units, the cooperative aggregation comprising:

a plurality of the router/switch units;

a switching network including and interconnecting said plurality of router/switch units,

wherein the cooperative aggregation functions as a single router from a perspective of an external network device coupled to the system.

2. The cooperative aggregation of claim 1, wherein each router/switch unit comprises an Internet protocol (IP) router adapted to function as part of the aggregation.

3. The cooperative aggregation of claim 1, wherein interconnections of the switching network provide multiple paths to communicate packets between any two router/switch units.

4. The cooperative aggregation of claim 3, wherein the switching network comprises a switching mesh.

5. The cooperative aggregation of claim 1, further comprising:

a first protocol configured to share routing information between the router/switch units of the aggregation.

6. The cooperative aggregation of claim 5, wherein the routing information is shared such that each router/switch unit is capable of determining whether a destination IP address for a packet is within an IP subnet that is directly or externally connected to one of the router/switch units.

7. The cooperative aggregation of claim 5, further comprising:

a second protocol configured to share ARP cache information between the router/switch units of the aggregation.

8. The cooperative aggregation of claim 7, wherein the ARP cache information includes cached MAC addresses for end hosts in the directly-connected subnets and cached MAC addresses for next-hop routers in the externally-connected subnets.

9. The cooperative aggregation of claim 1, wherein, when an initially receiving router/switch unit receives a packet from outside the aggregation, the initially receiving router/switch unit performs routing functions while the other router/switch units do not perform routing functions with respect to that packet.

10. The cooperative aggregation of claim 9, wherein one or more of the other router/switch units perform switching with respect to that packet.

11. The cooperative aggregation of claim 1, wherein, when an initially receiving router/switch unit receives a multicast packet from outside the aggregation, the initially receiving router/switch unit performs routing functions and uses a broadcast map to send the-multicast packet to all other router/switch units of the aggregation, and wherein the other router/switch units replicate and forward the multicast packet out those ports external to the aggregation where multicast joins have occurred.

12. A method of routing a packet by way of a router aggregation, the method comprising:

receiving a packet from outside the aggregation by an initially receiving router/switch unit;

performing router functions by the initially receiving router unit, including modification of the packet; and

sending the packet to a layer 2 network of the aggregation, wherein switching functions are performed on the packet.

13. The method of claim 12, further comprising layer 2 switching of the packet by other router/switch units of the aggregation.

14. The method of claim 13, wherein each router/switch unit comprises an Internet protocol (IP) router adapted to function as part of the aggregation.

15. The method of claim 12, wherein the layer 2 network provide multiple paths to communicate packets between any two router/switch units.

16. The method of claim 15, wherein the layer 2 network comprises a switching mesh.

17. The method of claim 12, further comprising:

sharing routing information between the router/switch units of the aggregation.

18. The method of claim 17, wherein the routing information is shared such that each router/switch unit is capable of determining whether a destination IP address for a packet is within an IP subnet that is directly or externally connected to one of the router/switch units.

19. The method of claim 17, further comprising:

Sharing ARP cache information between the router/switch units of the aggregation.

20. The method of claim 19, wherein the ARP cache information includes cached MAC addresses for end hosts in the directly-connected subnets and cached MAC addresses for next-hop routers in the externally-connected subnets.

21. An apparatus configured to route a packet as part of a router aggregation, the method comprising:

means for receiving a packet from outside the aggregation by an initially receiving router/switch unit;

means for performing router functions by the initially receiving router unit, including modification of the packet; and

means for sending the packet to a layer 2 network of the aggregation wherein switching functions are performed on the packet.