Virtual LANs

• US 6,560,236 B1
• Filed: 10/04/1999
• Issued: 05/06/2003
• Est. Priority Date: 06/23/1993
• Status: Expired due to Fees

• Current Assignee: Extreme Networks, Inc.
• Original Assignee: Enterasys Networks Incorporated (Extreme Networks, Inc.)
• Inventors: Simcoe, Robert, Spinney, Barry A., Cobb, Graham, Higginson, Peter, Thomas, Robert Eugene, Bassett, John, Varghese, George
• Primary Examiner(s): Patel, Ajit
• Application Number:
  US09/411,773
• Time in Patent Office: 1,310 Days
• Field of Search: 370/254, 370/259, 370/260, 370/261, 370/262, 370/263, 370/264, 370/265, 370/270, 370/351, 370/389, 370/390, 370/431, 370/432, 370/908, 370/911, 370/912, 370/312, 370/401, 379/156, 379/157, 379/158, 379/202.01, 379/221.15, 379/901
• US Class Current: 370/401
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• 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 12/467 Arrangements for supporting untagged frames, e.g. port-based VLANs

Abstract

A network device for interconnecting computer networks, the device including a bridge having a plurality of ports through which network communications pass to and from the bridge, the bridge also including a first interface enabling a user to partition the plurality of bridge ports into a plurality of groups, wherein each group represents a different virtual network, wherein the bridge treats all ports within a given group as part of the virtual network corresponding to that group and the bridge isolates the virtual networks from each other, whereby any communications received at a first port of the bridge are directly sent by the bridge to another bridge port only if the other bridge port and the first bridge port are part of the same group.

Claims

1. A method of operating a network bridge having a first plurality of ports through which network communications pass to and from the bridge, the method comprising:

assigning a group identifier to each port of the first plurality of ports, wherein all ports with a same assigned group identifier are in a same group;

receiving a communication on a first port of the bridge; and

if the first port is one of the first plurality of ports and the communication is a multicast packet having a multicast destination address, sending the communication out of the bridge on all other ports of the first plurality of ports having the same assigned group identifier as the first port.

2. The method of claim 1, further comprising:

identifying a source of the communication received on the first port of the bridge.

3. The method of claim 2, further comprising:

identifying a destination of the communication;

determining a group identifier assigned to the destination; and

if the group identifier assigned to the destination and the group identifier assigned to the source are different, sending the communication out a client port not within the first plurality of ports.

4. The method of claim 1, wherein the bridge includes a client port not included within the first plurality of ports and the communication is a multicast packet, the method comprising:

receiving the multicast packet on the client port;

identifying a group identifier within the multicast packet; and

sending the multicast packet out on those ports having the same group identifier as the group identifier within the received multicast packet.

5. The method of claim 4, wherein:

the group identifier is removed from the multicast packet before sending the multicast packet out from the bridge.

6. The method of claim 1, further comprising:

assigning a protocol type to each group identifier;

wherein, for each port of first plurality of ports, the protocol type identifies a communication protocol used by a station connected to the port.

7. The method of claim 6, wherein no two distinct group identifiers having a same protocol type are assigned to a same port.

8. The method of claim 1, wherein a port may have more than one group identifier assigned to it.

9. A method of operating a network bridge having a first plurality of ports through which network communications pass to and from the bridge, the method comprising:

assigning a group identifier to each port of the first plurality of ports, wherein all ports with a same assigned group identifier are in a same group;

receiving a communication on a first port of the bridge;

if the first port is one of the first plurality of ports, sending the communication out of the bridge on all other ports of the first plurality of ports having the same assigned group identifier as the first port;

identifying a source of the communication received on the first port of the bridge;

identifying a destination of the communication;

determining a group identifier assigned to the destination; and

if the group identifier assigned to the destination and the group identifier assigned to the source are different, sending the communication out a client port not included within the first plurality of ports and indicating the group identifier assigned to the first port within the communication sent out the client port.

10. The method of claim 9, wherein the step of indicating the group identifier comprises:

replacing a redundant field within the communication with the group identifier.

11. A method of operating a network bridge having a first plurality of ports through which network communications pass to and from the bridge, the method comprising:

assigning a group identifier to each port of the first plurality of ports, wherein all ports with a same assigned group identifier are in a same group;

connecting a router to a client port of the bridge not within the first plurality of ports;

identifying the ports on the router connected to the network bridge;

defining, on the router, a correspondence between the identified ports connected to the network bridge and each distinct group identifier;

receiving a communication on a first port of the bridge;

if the first port is one of the first plurality of ports, sending the communication out of the bridge on all other ports of the bridge having the same assigned group identifier as the first port;

identifying a source of the communication received on the first port of the bridge;

identifying a destination of the communication;

determining a group identifier assigned to the destination; and

if the group identifier assigned to the destination and the group identifier assigned to the source are different, sending the communication out the client port.

12. The method of claim 11, further comprising:

receiving a second communication from the bridge at the router; and

determining a group identifier of the second communication.

13. The method of claim 11, further comprising:

sending a second communication from the router to the bridge,

wherein the second communication comprises a first group identifier, and

wherein the second communication comprises a source address of the router assigned to the first group identifier.

14. The method of claim 11, further comprising:

maintaining, at the router, a record of a source address of each communication from the bridge and a respective group identifier.

15. A computer program product for use with a network device having a computer and a first plurality of ports on which network communications pass to and from the network device, wherein the network device includes a client port not within the first plurality of ports, and the computer program product comprises computer program instructions that when executed by the computer direct the computer to perform a method of directing the network communications, the method comprising:

assigning a group identifier to each port of the first plurality of ports, wherein all ports with a same assigned group identifier are in a same group;

receiving a communication on a first port of the network device;

if the first port is one of the first plurality of ports, sending the communication out of the network device on all other ports of the first plurality of ports having the same assigned group identifier as the first port;

receiving a multicast packet having a multicast destination address on the client port;

identifying a group identifier within the multicast packet; and

sending the multicast packet out on those ports having the same group identifier as the group identifier within the received multicast packet,

wherein the group identifier is removed from the multicast packet before sending the multicast packet out from the network device.

16. The computer program product of claim 15, wherein the method further comprises:

identifying a source of the communication received on the first port.

17. The computer program product of claim 16, wherein the method further comprises:

identifying a destination of the communication;

determining a group identifier assigned to the destination; and

if the group identifier assigned to the destination and a group identifier assigned to the source are different, sending the communication out a client port not within the first plurality of ports.

18. A computer program product for use with a network device having a computer and a first plurality of ports on which network communications pass to and from the network device, the computer program product comprising computer program instructions that when executed by the computer direct the computer to perform a method of directing the network communications, the method comprising:

assigning a group identifier to each port of the first plurality of ports, wherein all ports with a same assigned group identifier are in a same group;

receiving a communication on a first port of the network device;

if the first port is one of the first plurality of ports, sending the communication out of the network device on all of the ports of the first plurality of ports having the same assigned group identifier as the first port;

identifying a source of the communication received on the first port;

identifying a destination of the communication;

determining a group identifier assigned to the destination; and

if the group identifier assigns to the destination and the group identifier assigned to the source are different, sending the communication out a client port not within the first plurality of ports, indicating the group identifier of the first port within the communication sent out the client port and replacing a redundant field within the communication with the group identifier.