Virtual local area networks having rules of precedence

• US 6,526,052 B1
• Filed: 12/23/1998
• Issued: 02/25/2003
• Est. Priority Date: 12/23/1998
• Status: Expired due to Term

• Current Assignee: Extreme Networks, Inc.
• Original Assignee: Enterasys Networks Incorporated (Extreme Networks, Inc.)
• Inventors: Yang, Henry S., Rijhsinghani, Anil
• Primary Examiner(s): VINCENT, DAVID ROBERT
• Application Number:
  US09/221,333
• Time in Patent Office: 1,525 Days
• Field of Search: 370/400-403, 370/395.1, 370/395.5, 370/395.53, 370/396, 370/398, 370/389, 709/227, 709/230
• US Class Current: 370/389
• CPC Class Codes: H04L 12/4645 Details on frame tagging routing of packets H04L45/00; support for virtual LAN H04L49/354
• CPC Class Codes: H04L 12/467 Arrangements for supporting untagged frames, e.g. port-based VLANs

Abstract

A switch for use in a communications system having multiple local area networks interconnected by multiple switches so as to be configurable into different types of virtual local area networks includes first and second communication ports. The first communication port is connected directly to a local area network and the second communication port interconnects with other system switches. A switch control detects a communication from the local area network and identifies a virtual local area network over which the communication is to be transmitted based upon rules of precedence for different types of virtual local area networks. The communication is appended with a VLAN tag representing the identified virtual local area network so as to form a VLAN communication that is directed to the second communication port for transmission over the identified virtual local area network.

Claims

1. A method of selecting a VLAN from among a plurality of VLANs to assign to a packet received at a network device of a communications network, wherein each VLAN has membership criteria based on one or more aspects of the communications network and each VLAN has a VLAN classification based on its membership criteria, the method comprising acts of:

(A) determining one or more characteristics associated with the packet received at a first port of the network device, the one or more characteristics including the first port;

(B) determining one or more VLANs having membership criteria satisfied by the determined characteristics, a first of the determined VLANs having a first VLAN classification based on membership criteria that includes network device ports;

(C) if more than one VLAN is determined, selecting the first determined VLAN based on a precedence order of VLAN classifications, the precedence order specifying that the first VLAN classification has precedence over other VLAN classifications; and

(D) assigning the first determined VLAN to the received packet.

2. The method of claim 1, wherein the network device is a switch.

3. The method of claim 1, wherein the precedence order specifies that the first VLAN classification has a highest precedence over all other VLAN classifications.

4. The method of claim 3, wherein the network device is a switch.

5. The method of claim 1, wherein the first VLAN classification is a port-based VLAN classification.

6. The method of claim 5, wherein the precedence order specifies that the first VLAN classification has a highest precedence over all other VLAN classifications.

7. The method of claim 5, wherein the network device is a switch.

8. The method of claim 5, wherein another of the plurality of determined VLANs has at least one of the following VLAN classifications:

address-and-protocol-based, address-based, and protocol-based.

9. The method of claim 1, wherein the first VLAN classification is a port-and-protocol-based VLAN classification.

10. The method of claim 9, wherein the precedence order specifies that the first VLAN classification has a highest precedence over all other VLAN classifications.

11. The method of claim 9, wherein the network device is a switch.

12. The method of claim 9, wherein another of the plurality of determined VLANs has at least one of the following VLAN classifications:

port-based, address-and-protocol-based, address-based, and protocol-based.

13. A system for selecting a VLAN from among a plurality of VLANs to assign to a packet received at a network device of a communications network, wherein each VLAN has membership criteria based on one or more aspects of the communications network and each VLAN has a VLAN classification based on its membership criteria, the system comprising:

a control module to determine one or more characteristics associated with the packet received at a first port of the network device, the one or more characteristics including the first port, to determine one or more VLANs having membership criteria satisfied by the determined characteristics, a first of the determined VLANs having a first VLAN classification based on membership criteria that includes network device ports, to select the first determined VLAN, if more than one VLAN is determined, based on a precedence order of VLAN classifications, the precedence order specifying that the first VLAN classification has precedence over other VLAN classifications, and to assign the first determined VLAN to the received packet.

14. The system of claim 13, wherein the network device is a switch.

15. The system of claim 13, wherein the precedence order specifies that the first VLAN classification has a highest precedence over all other VLAN classifications.

16. The system of claim 15, wherein the network device is a switch.

17. The system of claim 13, wherein the first VLAN classification is a port-based VLAN classification.

18. The system of claim 17, wherein the precedence order specifies that the first VLAN classification has a highest precedence over all other VLAN classifications.

19. The system of claim 17, wherein the network device is a switch.

20. The system of claim 17, wherein another of the plurality of determined VLANs has at least one of the following VLAN classifications:

address-and-protocol-based, address-based, and protocol-based.

21. The system of claim 13, wherein the first VLAN classification is a port-and-protocol-based VLAN classification.

22. The system of claim 21, wherein the precedence order specifies that the first VLAN classification has a highest precedence over all other VLAN classifications.

23. The system of claim 21, wherein the network device is a switch.

24. The system of claim 21, wherein another of the plurality of determined VLANs has at least one of the following VLAN classifications:

port-based, address-and-protocol-based, address-based, and protocol-based.

25. A system for selecting a VLAN from among a plurality of VLANs to assign to a packet received at a network device of a communications network, wherein each VLAN has membership criteria based on one or more aspects of the communications network and each VLAN has a VLAN classification based on its membership criteria, the system comprising:

a control module to determine one or more characteristics associated with the packet received at a first port of the network device, the one or more characteristics including the first port, to determine one or more VLANs having membership criteria satisfied by the determined characteristics, a first of the determined VLANs having a first VLAN classification based on membership criteria that includes network device ports, and to assign the first determined VLAN to the received packet; and

means for selecting, in the event that more than on VLAN is determined, the first determined VLAN based on a precedence order of VLAN classifications, the precedence order specifying that the first VLAN classification has precedence over other VLAN classifications.

26. The system of claim 25, wherein the network device is a switch.

27. The system of claim 25, wherein the precedence order specifies that the first VLAN classification has a highest precedence over all other VLAN classifications.

28. The system of claim 27, wherein the network device is a switch.

29. The system of claim 25, wherein the first VLAN classification is a port-based VLAN classification.

30. The system of claim 29, wherein the precedence order specifies that the first VLAN classification has a highest precedence over all other VLAN classifications.

31. The system of claim 29, wherein the network device is a switch.

32. The system of claim 29, wherein another of the plurality of determined VLANs has at least one of the following VLAN classifications:

address-and-protocol-based, address-based, and protocol-based.

33. The system of claim 25, wherein the first VLAN classification is a port-and-protocol-based VLAN classification.

34. The system of claim 33, wherein the precedence order specifies that the first VLAN classification has a highest precedence over all other VLAN classifications.

35. The system of claim 33, wherein the network device is a switch.

36. The system of claim 33, wherein another of the plurality of determined VLANs has at least one of the following VLAN classifications:

port-based, address-and-protocol-based, address-based, and protocol-based.