Fabric switching

1. A switch, comprising:

one or more ports;

control circuitry configured to:

maintain a membership in a network of interconnected switches, wherein the network of interconnected switches is identified by a fabric identifier, and wherein the fabric identifier is distinct from a first switch identifier identifying the switch in the network of interconnected switches; and

determine that the switch has joined the network of interconnected switches based on the fabric identifier; and

forwarding circuitry configured to encapsulate a packet with an encapsulation header forwardable in an Internet Protocol (IP) network in accordance with a tunneling protocol, wherein a source and a destination addresses of the encapsulation header correspond to the first switch identifier and a second switch identifier of a second switch in the network of interconnected switches, respectively, and wherein the second switch shares the fabric identifier with the switch,

wherein the control circuitry is further configured to maintain configuration information for a respective switch of the network of interconnected switches in a data structure in a storage device within the switch, and configured to reassign the second switch identifier to the second switch in response to the second switch leaving and rejoining the network of interconnected switches.

2. The switch of claim 1 , wherein the forwarding circuitry is further configured to further encapsulate the encapsulated packet with an outer Ethernet header.

3. The switch of claim 1 , wherein the forwarding circuitry is further configured to determine a next-hop switch corresponding to the second switch identifier for the encapsulated packet.

4. The switch of claim 1 , wherein the configuration information for the second switch comprises the second switch identifier and a switch index identifying the configuration information for the second switch in the data structure.

5. The switch of claim 1 , wherein the control circuitry is further configured to construct a message for the second switch in response to learning a media access control (MAC) address from a port of the one or more ports, wherein a payload of the message comprises the MAC address and a virtual local area network (VLAN) identifier associated with the MAC address.

6. The switch of claim 1 , wherein the forwarding circuitry is further configured to query a name service data structure based on the packet's destination media access control (MAC) address and a virtual local area network (VLAN) identifier, wherein the name service is configured to maintain a mapping between a respective MAC address learned at the network of interconnected switches and a corresponding VLAN identifier.

7. The switch of claim 1 , wherein the control circuitry is further configured to determine a route between the switch and the second switch based on a routing protocol.

8. A switching system, comprising:

a plurality of interconnected switches;

control circuitry residing on a respective switch of the plurality of interconnected switches;

wherein the control circuitry is configured to:

maintain a membership in the switching system, wherein the switching system is identified by a fabric identifier, and wherein the fabric identifier is distinct from a first switch identifier identifying a first switch in the switching system; and

determine that the switch has joined the switching system based on the fabric identifier; and

wherein forwarding circuitry residing on the first switch of the switching system is configured to encapsulate a packet with an encapsulation header forwardable in an Internet Protocol (IP) network in accordance with a tunneling protocol, wherein a source and a destination addresses of the encapsulation header correspond to the first switch identifier and a second switch identifier of a second switch in the switching system, respectively, and wherein the second switch shares the fabric identifier with the first switch,

wherein the control circuitry is further configured to maintain configuration information for a respective switch of the switching system of interconnected switches in a data structure in a storage device within the switch, and configured to reassign the second switch identifier to the second switch in response to the second switch leaving and rejoining the network of interconnected switches.

9. The switching system of claim 8 , wherein forwarding circuitry residing on the first switch is configured to determine a next-hop switch based on the second switch identifier for the encapsulated packet.

10. The switching system of claim 8 , wherein a respective switch of the switching system maintains configuration information of all the switches in the switching system in a data structure in a local storage device, wherein the configuration information for the second switch comprises the second switch identifier and a switch index identifying the configuration information for the second switch in the data structure.

11. The switching system of claim 8 , wherein the forwarding circuitry residing on the first switch is further configured to query a name service data structure based on the packet's destination media access control (MAC) address and a virtual local area network (VLAN) identifier, wherein the name service is further configured to maintain a mapping between a respective MAC address learned at the switching system and a corresponding VLAN identifier.

12. A method, comprising:

maintaining, by a switch, a membership in a network of interconnected switches, wherein the network of interconnected switches is identified by a fabric identifier, and wherein the fabric identifier is distinct from a first switch identifier identifying the switch in the network of interconnected switches;

determining that the switch has joined the network of interconnected switches based on the fabric identifier;

encapsulating a packet with an encapsulation header forwardable in an Internet Protocol (IP) network in accordance with a tunneling protocol, wherein a source and a destination addresses of the encapsulation header correspond to the first switch identifier and a second switch identifier of a second switch in the network of interconnected switches, respectively, and wherein the second switch shares the fabric identifier with the switch;

maintaining configuration information for a respective switch of the network of interconnected switches in a data structure in a storage device within the switch; and

reassigning the second switch identifier to the second switch in response to the second switch leaving and rejoining the network of interconnected switches.

13. The method of claim 12 , further comprising determining a next-hop switch corresponding to the second switch identifier for the encapsulated packet.

14. The method of claim 12 , further comprising maintaining configuration information for a respective switch of the network of interconnected switches in a data structure in a storage device of the switch, wherein the configuration information for the second switch comprises the second switch identifier and a switch index identifying the configuration information for the second switch in the data structure.

15. The method of claim 12 , further comprising determining a route between the switch and the second switch based on a routing protocol.

16. A computing system, comprising:

a processor;

a storage device coupled to the processor and storing instructions that when executed by a computer cause the computer to perform a method, the method comprising:

maintaining a membership in a network of interconnected switches, wherein the network of interconnected switches is identified by a fabric identifier, and wherein the fabric identifier is distinct from a first switch identifier identifying the computing system in the network of interconnected switches;

determining that the computing system has joined the network of interconnected switches based on the fabric identifier;

encapsulating a packet with an encapsulation header forwardable in an Internet Protocol (IP) network in accordance with a tunneling protocol, wherein a source and a destination addresses of the encapsulation header correspond to the first switch identifier and a second switch identifier of a second computing system in the network of interconnected switches, respectively, and wherein the second computing system shares the fabric identifier with the computing system;

maintaining configuration information for a respective switch of the network of interconnected switches in a data structure in a storage device within the switch; and

reassigning the second switch identifier to the second switch in response to the second switch leaving and rejoining the network of interconnected switches.