Virtual Layer 2 and Mechanism to Make it Scalable

• US 20120014387A1
• Filed: 05/27/2011
• Published: 01/19/2012
• Est. Priority Date: 05/28/2010
• Status: Active Grant

• Current Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Inventors: Dunbar, Linda, Mack-Crane, T. Benjamin, Hares, Susan, Sultan, Robert, Ashwood-Smith, Peter, Yin, Guoli
• Granted Patent: US 9,160,609 B2
• Time in Patent Office: Days
• US Class Current: 370/395.53
• CPC Class Codes: H04L 12/462 LAN interconnection over a bridge based backbone
• CPC Class Codes: H04L 12/4625 Single bridge functionality, e.g. connection of two networks over a single bridge
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• 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 12/4675 Dynamic sharing of VLAN information amongst network nodes configuration of the network or of network elements H04L41/08
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04L 41/12 Discovery or management of network topologies
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/66 Layer 2 routing, e.g. in Ethernet based MAN's
• CPC Class Codes: H04L 61/103 across network layers, e.g. resolution of network layer into physical layer addresses or address resolution protocol [ARP]

Abstract

An apparatus comprising a service network and a plurality of Layer 2 networks at a plurality of different physical locations coupled to the service network via a plurality of edge nodes at the Layer 2 networks, wherein the edge nodes are configured to maintain a plurality of Internet Protocol (IP) addresses of a plurality of hosts across the Layer 2 networks, and wherein the IP addresses of the hosts in each of the Layer 2 networks are mapped by the other Layer 2 networks to a Media Access Control (MAC) address of each of the edge nodes in the same Layer 2 networks of the hosts.

Claims

1. An apparatus comprising:

a service network; and

a plurality of Layer 2 networks at a plurality of different physical locations coupled to the service network via a plurality of edge nodes at the Layer 2 networks,

wherein the edge nodes are configured to maintain a plurality of Internet Protocol (IP) addresses of a plurality of hosts across the Layer 2 networks, and

wherein the IP addresses of the hosts in each of the Layer 2 networks are mapped by the other Layer 2 networks to a Media Access Control (MAC) address of each of the edge nodes in the same Layer 2 networks of the hosts.

2. The apparatus of claim 1, wherein the edge nodes are not aware of the MAC addresses of the hosts that have IP addresses.

3. The apparatus of claim 1, wherein the edge nodes are also configured to maintain a plurality of MAC addresses for a plurality of non-IP applications.

4. The apparatus of claim 1, wherein the service network is one of a Layer 3 network, a Layer 2.5 network, and a Layer 2 network.

5. The apparatus of claim 1, wherein the edge nodes are Layer 2 gateways, wherein the hosts comprise a plurality of applications, servers, and/or virtual machines, and wherein the Layer 2 networks may be located at different data centers (DCs).

6. The apparatus of claim 1, wherein the hosts in the Layer 2 networks are not aware of the MAC addresses of the hosts in the other Layer 2 networks.

7. The apparatus of claim 1, wherein the edge nodes comprise a plurality of local IP address information tables that comprise the IP addresses of the hosts in all the Layer 2 networks and a plurality of MAC address forwarding tables that comprise a plurality of MAC addresses for only local hosts in the same Layer 2 networks of the edge nodes, for a plurality of non-IP applications in the Layer 2 networks, or both.

8. The apparatus of claim 1, wherein a plurality of switches in the Layer 2 networks act as delegates for the edge nodes, and wherein the switches receive and maintain a plurality of different subsets of IP addresses from the corresponding edge nodes.

9. The apparatus of claim 1, wherein a plurality of switches in the Layer 2 networks act as Address Resolution Protocol (ARP) proxies, and wherein the ARP proxies exchange a plurality of ARP requests and responses with the hosts in the same Layer 2 networks as the switches.

10. A network component comprising:

a receiver configured to receive a plurality of Internet Protocol (IP) addresses for a plurality of hosts in a plurality of external Layer 2 networks located at a plurality of physical locations and interconnected via a service;

a logic circuit configured to map the IP addresses of the hosts in the external Layer 2 networks to a plurality of Media Access Control (MAC) addresses of a plurality of corresponding gateways in the same external Layer 2 networks, and

a transmitter configured to send to the external Layer 2 networks a plurality of a plurality of IP addresses for a plurality of local hosts in a local Layer 2 network coupled to the external Layer 2 networks via the service.

11. The network component of claim 10, wherein the IP addresses of the hosts in a plurality of virtual local area networks (VLANs) in a single data center (DC) location are mapped to the same one of the MAC addresses of the external gateways.

12. The network component of claim 11, wherein the hosts are associated with a plurality of virtual private groups (VPGs) or closed user groups in one of the VLANs in the DC location.

13. The network component of claim 10, wherein a plurality of IP addresses of the local hosts are sent on a periodic basis or when changes occur to the local hosts or the IP addresses of the local hosts to update address information in the external Layer 2 networks.

14. A method comprising:

receiving a frame from a first host in a first data center (DC) location that is intended for a second host in a second DC location;

mapping a destination address (DA) for the second host in the frame to a Media Access Control (MAC) address of a Layer 2 Gateway (L2GW) in the second DC location;

adding an outer MAC header that supports Institute of Electrical and Electronics Engineers (IEEE) 802.1ah standard for MAC-in-MAC to obtain an inner frame that indicates the MAC address of the L2GW; and

sending the inner frame to the second DC location via a service instance coupled to the second DC location.

15. The method of claim 14, wherein the frame comprises a MAC DA for a local L2GW in the first DC location, a MAC source address (SA) for the first host, an Internet Protocol (IP) DA for the second host, and an IP SA for the first host, wherein the outer MAC header comprises a MAC DA for the L2GW, a MAC SA for the local L2GW, and an Ether Type that indicates that the inner frame needs MAC address translation, and wherein the inner frame comprises the outer MAC frame, the MAC DA for the local L2GW, and the MAC SA of the first host.

16. The method of claim 14, wherein the second host is a non-Internet Protocol (IP) application, wherein the frame comprises a MAC DA for a local L2GW in the first DC location and a MAC source address (SA) for the first host, wherein the outer MAC header comprises a MAC DA for the L2GW, a MAC SA for the local L2GW, and an Ether Type that indicates that the inner frame is for MAC-in-MAC, and wherein the inner frame comprises the outer MAC frame, a MAC DA for the second host, and the MAC SA of the first host.

17. The method of claim 14, wherein the second host moved from a previous DC location to the second DC location, wherein the frame comprises a MAC DA for a local L2GW in the first DC location, a MAC source address (SA) for the first host, an Internet Protocol (IP) DA for the second host, and an IP SA for the first host, wherein the outer MAC header comprises a MAC DA for the L2GW, a MAC SA for the local L2GW, and an Ether Type that indicates that the inner frame needs MAC address translation, and wherein the inner frame comprises the outer MAC frame, a MAC DA for the second host learned from the previous DC location and the MAC SA of the first host.

18. The method of claim 14 further comprising:

receiving an Address Resolution Protocol (ARP) request from a local host in the first DC location to obtain a MAC address of an external host in another DC location; and

returning an ARP reply to the local host that indicates the MAC address of a local L2GW in the first DC location on behalf of the external host if an Internet Protocol (IP) address of the external host is detected in an IP address information table of the local L2GW.

19. The method of claim 18 further comprising:

sending an Address Resolution Protocol (ARP) message to a host to obtain an update from the host; and

updating an entry of the host in the IP address information table if an ARP reply is received from the host.

20. The method of claim 14 further comprising:

pushing a plurality of Internet Protocol (IP) addresses for a plurality of hosts from an IP address information table to a plurality of delegate switches that serve as Address Resolution Protocol (ARP) proxies; and

receiving a consolidated list of updated IP addresses for the hosts from the delegate switches.