Layer-3 support in TRILL networks

• US 9,270,572 B2
• Filed: 12/06/2011
• Issued: 02/23/2016
• Est. Priority Date: 05/02/2011
• Status: Expired due to Fees

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Brocade Communications Systems, Inc. (Broadcom, Inc.)
• Inventors: Koganti, Phanidhar, Ghanwani, Anoop, Vobbilisetty, Suresh, Krishnamurthy, Rajiv, Venkatesan, Nagarajan, Yu, Shunjia
• Primary Examiner(s): Lai, Andrew
• Assistant Examiner(s): Qin, Zhiren
• Application Number:
  US13/312,903
• Publication Number:
  US 20120281700A1
• Time in Patent Office: 1,540 Days
• Field of Search: 370/392, 370/351, 370/352
• US Class Current: 1/1
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 49/60 Software-defined switches

Abstract

One embodiment of the present invention provides a switch. The switch includes an IP header processor and a forwarding mechanism. The IP header processor identifies a destination IP address in a packet encapsulated with an inner Ethernet header, a TRILL header, and an outer Ethernet header. The forwarding mechanism determines an output port and constructs a new header for the packet based on the destination IP address. The switch also includes a packet processor which determines whether (1) an inner destination media access control (MAC) address corresponds to a local MAC address assigned to the switch; (2) a destination RBridge identifier corresponds to a local RBridge identifier assigned to the switch; and (3) an outer destination MAC address corresponds to the local MAC address.

Claims

1. A switch, comprising:

layer-2 processing circuitry configured to determine that;

outer and inner destination media access control (MAC) addresses of a packet correspond to a MAC address assigned to the switch, wherein the packet is encapsulated with an inner Ethernet header, a routable header, and an outer Ethernet header;

encapsulation circuitry configured to determine that;

a destination switch identifier of the routable header corresponds to a switch identifier assigned to the switch, wherein the routable header is placed between the outer and inner Ethernet headers;

Internet Protocol (IP) processing circuitry configured to lookup a destination IP address of a layer-3 header of the packet in a local layer-3 forwarding table in the switch, wherein the layer-3 header is distinct from the routable header, and wherein the destination IP address is a virtual IP address assigned to a virtual IP router, which is formed based on the switch in conjunction with at least another physical switch to operate as a single router; and

forwarding circuitry configured to determine an output port and construct a new header for the packet based on looking up the destination IP address in the local layer-3 forwarding table.

2. The switch of claim 1, wherein the layer-2 processing circuitry is further configured to determine a first virtual local area network (VLAN) tag in the inner Ethernet header;

and

wherein the new header includes a new inner Ethernet header comprising a second VLAN tag.

3. The switch of claim 1, wherein the switch is a member of a network of interconnected switches, wherein the network of interconnected switches is controlled as a single logical switch.

4. The switch of claim 1, further comprising switching circuitry configured to switch the packet between VLANs based on the destination IP address.

5. The switch of claim 1, wherein the destination switch identifier is a virtual switch identifier;

and

wherein the virtual IP router is associated with the virtual switch identifier.

6. The switch of claim 1, wherein the IP processing circuitry is further configured to map the virtual IP address to a virtual media access control (MAC) address.

7. The switch of claim 1, further comprising Address Resolution Protocol (ARP) circuitry configured to generate an ARP response for an IP address assigned to the switch, wherein the ARP response comprises a MAC address assigned to the switch.

8. A method, comprising:

determining that;

outer and inner destination media access control (MAC) addresses of a packet correspond to a MAC address assigned to a switch, wherein the packet is encapsulated with an inner Ethernet header, a routable header, and an outer Ethernet header; and

a destination switch identifier of the routable header corresponds to a switch identifier assigned to the switch, wherein the routable header is placed between the outer and inner Ethernet headers;

looking up a destination Internet Protocol (IP) address of a layer-3 header of the packet in a local layer-3 forwarding table in the switch, wherein the layer-3 header is distinct from the routable header, and wherein the destination IP address is a virtual IP address assigned to a virtual IP router, which is formed based on the switch in conjunction with at least another physical switch to operate as a single router; and

determining an output port and constructing a new header for the packet based on looking up the destination IP address in the local layer-3 forwarding table.

9. The method of claim 8, further comprising:

determining a first virtual local area network (VLAN) tag in the inner Ethernet header; and

including in the new header a new inner Ethernet header comprising a second VLAN tag.

10. The method of claim 8, wherein the switch is a member of a network of interconnected switches wherein the network of interconnected switches is controlled as a single logical switch.

11. The method of claim 8, further comprising switching the packet between VLANs based on the destination IP address.

12. The method of claim 8, wherein the destination switch identifier is a virtual switch identifier;

and

wherein the virtual IP router is associated with the virtual switch identifier.

13. The method of claim 8, further comprising mapping the virtual IP address to a virtual media access control (MAC) address.

14. The method of claim 8, further comprising generating an Address Resolution Protocol (ARP) response for an IP address assigned to the switch, wherein the ARP response comprises a MAC address assigned to the switch.

15. A computing system, comprising:

a processor; and

a non-transitory computer-readable storage medium storing instructions which when executed by the processor causes the processor to perform a method, the method comprising;

determining that;

outer and inner destination media access control (MAC) addresses of a packet correspond to a MAC address assigned to the computing system, wherein the packet is encapsulated with an inner Ethernet header, a routable header, and an outer Ethernet header; and

a destination switch identifier of the routable header corresponds to a switch identifier is assigned to the computing system;

looking up a destination Internet Protocol (IP) address of a layer-3 header of the packet in a local layer-3 forwarding table in the computing system, wherein the layer-3 header is distinct from the routable header and wherein the destination IP address is a virtual IP address assigned to a virtual IP router, which is formed based on the switch in conjunction with at least another physical switch to operate as a single router; and

determining an output port and constructing a new header for the packet based on looking up the destination IP address in the local-layer-3 forwarding table.

16. The computing system of claim 15, within the method further comprises:

determining a first virtual local area network (VLAN) tag in the inner Ethernet header; and

including in the new header a new inner Ethernet header comprising a second VLAN tag.

17. The computing system of claim 15, wherein the computing system is a member of a network of interconnected switches, wherein the network of interconnected switches is controlled as a single logical switch.

18. The computing system of claim 15,

wherein the destination switch identifier is a virtual switch identifier;

and

wherein the virtual IP router is associated with the virtual switch identifier.

19. The computing system of claim 15, wherein the method further comprises generating an Address Resolution Protocol (ARP) response for an IP address assigned to the computing system, wherein the ARP response comprises a MAC address assigned to the computing system.

20. The computing system of claim 15, whether the method further comprises switching the packet between VLANs based on the destination IP address.