Virtual network architecture for connectionless LAN backbone

• US 6,041,166 A
• Filed: 07/15/1996
• Issued: 03/21/2000
• Est. Priority Date: 07/14/1995
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: 3Com Corporation (HP Inc.)
• Inventors: Sherer, W. Paul, Hart, John H.
• Primary Examiner(s): Geckil, Mehmet B.
• Application Number:
  US08/683,570
• Time in Patent Office: 1,345 Days
• Field of Search: 395/200.68, 395/200.76, 395/200.6, 395/200.75, 395/200.5, 370/401, 370/351-356, 370/409
• US Class Current: 709/238
• CPC Class Codes: G06F 9/542 Event management; Broadcasting; Multicasting; Notifications
• CPC Class Codes: H04L 12/1836 with heterogeneous network architecture
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• CPC Class Codes: H04L 12/46 Interconnection of networks
• CPC Class Codes: H04L 12/4608 LAN interconnection over ATM networks
• 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 2012/5615 Network termination, e.g. NT1, NT2, PBX
• CPC Class Codes: H04L 2012/5616 Terminal equipment, e.g. codecs, synch.
• CPC Class Codes: H04L 2212/00 Encapsulation of packets
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections

Abstract

Network traffic management is achieved based on automatically setting up a plurality of virtual networks (VNETs) within a single large virtual LAN. Multicast/broadcast traffic is confined to the VNET of the source, without imposing constraints on layer two addressing within the virtual LAN. VNETs are domains of users of a virtual LAN which include members of logical networks defined at layer three or higher. One method includes transferring a multi-destination packet originating from a particular node in the virtual LAN by tunnelling across a connectionless backbone network to a virtual net server. The virtual net server translates the multi-destination packet to a plurality of tunneled messages identifying nodes authorized to receive multi-destination packets from members of the particular VNET which originated the packet. The tunneled messages are then forwarded from the virtual net server to the authorized nodes.

This way, multi-destination packets, such as advertisement or discovery packets, are confined to a single VNET. By confining the multi-destination packets to a single VNET, unicast packets generated within the virtual LAN are then also naturally confined to that VNET.

Claims

1. For a network including a set of local area net-work (LAN) segments, a backbone path, and a plurality of edge devices interconnecting the set of LAN segments with the backbone path, and in which nodes on respective LAN segments in the set are members of logical networks defined in layer three or higher, a method for managing traffic in the network, comprising:

detecting in response to a medium access control MAC address of a packet received at an edge device, a multi-destination packet originating from a particular LAN segment;

determining the logical network of the multi-destination packet;

translating the multi-destination packet to a plurality of tunneled messages carrying information from the multi-destination packet;

forwarding across the backbone path the plurality of tunneled messages to edge devices;

supplying the multi-destination packet in response to the tunneled messages from the edge devices receiving the directed messages to LAN segments through which nodes authorized to receive multi-destination packets from members of the determined logical network are accessible, except for the particular LAN segment on which the multi-destination packet originated; and

automatically learning members of logical networks in response to multi-destination packets;

wherein the backbone path includes a connectionless network.

2. The method of claim 1, wherein the connectionless network comprises one of a carrier sense multiple access protocol and a token passing ring protocol.

3. The method of claim 1, wherein the multi-destination packet comprises an address advertisement packet.

4. The method of claim 1, wherein the multi-destination packet comprises an address discovery packet.

5. The method of claim 1, including executing the steps of determining, translating and forwarding in a server coupled to the backbone communication path.

6. For a network including a set of local area network (LAN) segments, a connectionless LAN backbone path, and a plurality of edge devices interconnecting the plurality of LAN segments with the backbone path, and in which nodes on respective LAN segments in the set are members of logical networks defined in layer three or higher, a method for managing traffic in the network, comprising:

detecting in an edge device on an originating LAN segment, a multi-destination packet intended for members of a particular logical network, in response to a medium access control MAC address in the multi-destination packet;

producing in response to the detected multi-destination packet, a plurality of directed messages for nodes authorized to receive multi-destination packets of the particular logical network;

tunneling in the backbone path the plurality of directed messages to edge devices coupled to LAN segments through which the authorized nodes are accessible;

supplying the multi-destination packet in response to the directed messages, from the edge devices receiving the directed messages, to LAN segments, other than the originating LAN segment, through which authorized nodes are accessible;

in response to detected multi-destination packets, automatically configuring tunnel connections for each logical network to edge devices through which nodes intended to receive multi-destination packets of the logical network are accessible; and

associating the plurality of directed messages with configured tunnel connections for the identified logical network.

7. The method of claim 6, including:

tunneling the multi-destination packet from the edge device across the backbone path to a server; and

executing the steps of producing and forwarding in the server.

8. The method of claim 6, wherein the step of producing includes:

identifying the logical network of the multi-destination packet; and

composing the plurality of directed messages so that they identify nodes intended to receive multi-destination packets of the identified logical network.

9. The method of claim 8, wherein supplying the multi-destination packets from the edge devices includes:

mapping the configured tunnel connections to ports on the edge devices through which nodes authorized to receive multi-destination packet of the identified logical network are accessible; and

transmitting the multi-destination packet, in response to the mapping and the particular configured tunnel connection across which the directed message is received, to ports of the edge device other than a port coupled to the originating LAN segment.

10. The method of claim 9, including:

automatically configuring the configured tunnel connections in response to multi-destination packets received at the server, including

detecting in the server the logical network with which the multi-destination packet is associated and the source MAC address of the multi-destination packet,

establishing a tunnel connection with the edge device which detected the multi-destination packet, and

mapping in the edge device the tunnel connection to a port on which the source MAC address of the multi-destination packet is accessible.

11. The method of claim 6, wherein the multi-destination packet comprises an address advertisement packet.

12. The method of claim 6, wherein the multi-destination packet comprises an address discovery packet.

13. The method of claim 6, including:

learning in the edge devices the logical networks in use by nodes on respective ports of the edge devices; and

wherein the step of supplying is responsive to the learned logical networks.

14. For a network including a set of local area network (LAN) segments, a connectionless LAN backbone path, and a plurality of edge devices interconnecting the plurality of LAN segments with the backbone path, and in which nodes on respective LAN segments in the set are members of logical networks defined in layer three or higher, a method for managing traffic in the network, comprising:

detecting in a first edge device on an originating LAN segment, a multi-destination packet intended for members of a particular logical network, in response to a medium access control MAC address in the multi-destination packet, the edge device having ports coupled to the originating LAN segment and at least one additional LAN segment in the set;

first supplying the detected multi-destination packet out ports of the first edge device, other than the port coupled to the originating LAN segment, through which nodes authorized to receive messages from members of the particular logical network are accessible;

encapsulating and forwarding from the first edge device, the multi-destination packet as a single destination packet on the backbone path to a server;

producing in the server in response to the detected multi-destination packet, a plurality of directed messages for edge devices on the backbone path;

encapsulating and forwarding in respective single destination packets on the backbone path the plurality of directed messages to edge devices coupled to LAN segments through which the authorized nodes are accessible; and

second supplying the multi-destination packet in response to the directed messages, from edge devices receiving the directed messages, to LAN segments, other than LAN segments on the first edge device, through which authorized nodes are accessible.

15. The method of claim 14, wherein the multi-destination packet comprises an address advertisement packet.

16. The method of claim 14, wherein the multi-destination packet comprises an address discovery packet.

17. The method of claim 14, including:

learning in the edge devices the logical networks in use by nodes accessible through respective ports of the edge devices; and

wherein the step of first supplying and the step of second supplying are responsive to the learned logical networks.

18. For a network including a set of local area network (LAN) segments, a backbone path, and a plurality of edge devices interconnecting the set of LAN segments with the backbone path, the LAN segments interconnected as a virtual LAN, a server for managing traffic in the network, the server coupled to the backbone path, the server comprising:

resources on the server that receive a multidestination packet from an edge device, the multidestination packet having a multidestination address of a layer associated with a LAN;

a decoder that determines a logical network of the multidestination packet in response to a network protocol of the multidestination packet, wherein the logical network has membership less than the virtual LAN;

modules including modules associated with respective logical networks; and

resources that pass the multidestination packet to a module among the modules, the module associated with the logical network, the module tunneling the multidestination packet to an agent on a particular edge device, on which the agent forwards the packet out ports from which members of the logical network can be reached.

19. The server of claim 18, wherein the multidestination packet comprises a broadcast packet.

20. The server of claim 18, wherein the multidestination packet comprises a broadcast packet and the resources pass the broadcast packet only to a subset of modules among the modules, the subset including only modules associated with the logical network, so that the broadcast packet is not transmitted to all nodes in the virtual LAN.

21. The server of claim 18, wherein the multidestination packet comprises a broadcast packet and the agent forwards the broadcast packet only out a subset of ports on the edge device, the subset including only ports from which members of the logical network can be reached, so that the broadcast packet is not transmitted to all nodes in the virtual LAN.

22. The server of claim 18, wherein the multidestination packet includes a medium access control (MAC) layer multidestination address and the logical networks are defined in layer 3 or higher.