OVERLAY TRANSPORT VIRTUALIZATION

• US 20120176934A1
• Filed: 03/16/2012
• Published: 07/12/2012
• Est. Priority Date: 07/31/2007
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Farinacci, Dino, Speakman, Tony, Venugopal, Nair, Grover, Hasmit, Moreno, Victor, Rao, Dhananjaya
• Granted Patent: US 8,645,576 B2
• Time in Patent Office: Days
• US Class Current: 370/254
• CPC Class Codes: H04L 12/1886 with traffic restrictions for efficiency improvement, e.g. involving subnets or subdomains
• 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 2101/622 Layer-2 addresses, e.g. medium access control [MAC] addresses
• CPC Class Codes: H04L 61/103 across network layers, e.g. resolution of network layer into physical layer addresses or address resolution protocol [ARP]
• CPC Class Codes: H04L 61/106 across networks, e.g. mapping telephone numbers to data network addresses

Abstract

In one embodiment, an apparatus includes one or more internal interfaces in communication with one or more network devices in a first network site through a Layer 2 link, an overlay interface in communication through a Layer 3 link with a core network connected to one or more other network sites, and a table mapping addresses for network devices in the other network sites to addresses of edge devices in the same network site as the network device. The apparatus further includes a processor operable to encapsulate a packet received at one of the internal interfaces and destined for one of the network devices in the other network sites, with an IP header including a destination address of the edge device mapped to the destination network device, and forward the encapsulated packet to the core network.

Claims

1. A method comprising:

creating an overlay network between edge devices operating in different network sites and in communication through a core network, wherein creating said overlay network comprises mapping at a first edge device in a first network site, addresses for network devices located in one or more other network sites to addresses of the edge devices located in the same network sites as the network devices;

receiving a packet at said first edge device from a network device in said first network site, the packet comprising a destination address of one of the network devices in said one or more other network sites;

encapsulating the packet with a header comprising a destination address of the edge device mapped to the destination address of the network device; and

forwarding said encapsulated packet to the core network.

2. The method of claim 1 wherein state information for said overlay network is maintained at the edge devices.

3. The method of claim 1 wherein encapsulating the packet comprises encapsulating Layer 2 traffic with an IP header.

4. The method of claim 1 further comprising forwarding traffic from said first edge device to one of the network devices in said first network site using Layer 2 forwarding and wherein forwarding said encapsulated packet to the core network comprises forwarding traffic based on an IP header.

5. The method of claim 1 wherein the core network comprises a Layer 3 network and at least one of said network sites comprises a Layer 2 network.

6. The method of claim 1 wherein mapping comprises mapping a Media Access Control (MAC) address of the network device to an IP address of the edge device in the same network site.

7. The method of claim 6 wherein the MAC address is in a Layer 2-Virtual Private Network (VPN).

8. The method of claim 1 further comprising exchanging Interior Gateway Protocol (IGP) messages with the edge devices in said other network sites in said overlay network.

9. The method of claim 1 wherein said overlay network supports Layer 2 or Layer 3 Virtual Private Networks (VPNs) over a Layer 2 or Layer 3 infrastructure.

10. The method of claim 1 further comprising performing Internet Group Management Protocol (IGMP)/Multicast Listener Discovery (MLD) snooping within said first network site.

11. The method of claim 1 further comprising:

receiving a Layer 3 packet at said first edge device;

decapsulating the Layer 3 packet;

forwarding the decapsulated packet to a destination network device in said first network site using Layer 2 forwarding.

12. The method of claim 1 wherein said destination address is a multicast address.

13. The method of claim 1 further comprising selecting a first authoritative edge device for forwarding traffic from a source at said first network site and a second authoritative edge device for receiving said traffic at one of said other network sites.

14. The method of claim 1 wherein the core network comprises a Layer 3 network and at least one of said network sites is a Layer 2 network and at least one of said network sites is a Layer 3 network.

15. An apparatus comprising:

one or more internal interfaces for communication with one or more network devices in a first network site;

an overlay interface for communication in an overlay network with one or more edge devices located in one or more other network sites through a core network connecting said first network site to said one or more other network sites;

memory for storing a table mapping addresses for network devices in said one or more other network sites to addresses of said one or more edge devices in the same network sites as the network devices; and

a processor for encapsulating a packet received at one of the internal interfaces and destined for one of the network devices in said other network sites, with a header comprising a destination address of the edge device mapped to the address of the destination network device, and forwarding said encapsulated packet to the core network.

16. The apparatus of claim 15 wherein state information for said overlay network is maintained at the edge devices.

17. The apparatus of claim 15 wherein the apparatus is a Layer 2 switch.

18. The apparatus of claim 15 wherein the processor is further operable to decapsulate a packet received at the overlay interface and forward the decapsulated packet to a destination network device in said first network site.

19. The apparatus of claim 15 wherein said one or more internal interfaces are configured for communication with a Layer 2 link and said overlay interface is configured for communication with a Layer 3 link.

20. An apparatus comprising:

a processor for creating an overlay network between edge devices operating in different network sites and in communication through a core network, wherein creating said overlay network comprises mapping at a first edge device in a first network site, addresses for network devices located in one or more other network sites to addresses of the edge devices located in the same network sites as the network devices, receiving a packet at said first edge device from a network device in said first network site, the packet comprising a destination address of one of the network devices in said one or more other network sites, encapsulating the packet with a header comprising a destination address of the edge device mapped to the destination address of the network device, and forwarding said encapsulated packet to the core network; and

memory for storing said mapping.