VLAN PROTOCOL

• US 20090296717A1
• Filed: 08/11/2009
• Published: 12/03/2009
• Est. Priority Date: 07/08/1998
• Status: Active Grant

• Current Assignee: David Shemla, Eitan Medina
• Original Assignee: David Shemla, Eitan Medina
• Inventors: Shemla, David, Medina, Eitan
• Granted Patent: US 7,957,388 B2
• Time in Patent Office: Days
• US Class Current: 370/395.32
• 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 12/467 Arrangements for supporting untagged frames, e.g. port-based VLANs
• CPC Class Codes: H04L 2101/604 Address structures or formats
• CPC Class Codes: H04L 2101/622 Layer-2 addresses, e.g. medium access control [MAC] addresses
• CPC Class Codes: H04L 45/745 Address table lookup; Address filtering

Abstract

A switch controller includes a plurality of ports, a hash table, and a hash table control unit. The plurality of ports includes at least one bus port associated with ports connected to other switch controllers. The hash table stores MAC addresses and VLAN ids of ports within a network. The hash table control unit hashes a MAC address and a VLAN id of a packet to a first hash table location.

Claims

1. A switch controller comprising:

a plurality of ports including at least one bus port associated with ports connected to other switch controllers in a network;

a hash table for storing MAC addresses and VLAN ids of ports within the network; and

a hash table control unit for hashing a MAC address and a VLAN id of a packet to identify a first location in the hash table.

2. The switch controller of claim 1, wherein for each one of the VLAN ids stored in the hash table, one of the MAC addresses identifies one of the other switch controllers having ports belonging to the one of the VLAN ids without identifying each one of the ports of the one of the other switch controllers that belongs to the one of the VLAN ids.

3. The switch controller of claim 1, wherein for each one of the VLAN ids stored in the hash table, one of the MAC addresses identifies one of the plurality of ports of the switch controller that belongs to the one of the VLAN ids.

4. The switch controller of claim 2, wherein the switch controller identifies the one of the switch controllers from the hash table based on the MAC address and the VLAN id of the packet and forwards the packet to the one of the switch controllers.

5. The switch controller of claim 3, wherein the switch controller identifies the one of the plurality of ports of the switch controller from the hash table based on the MAC address and the VLAN id of the packet and forwards the packet to the one of the plurality of ports.

6. The switch controller of claim 1, wherein the hash table control unit comprises a hash table location generator that employs a hash function and that generates the first location from the MAC address and the VLAN id using the hash function.

7. The switch controller of claim 1, wherein the hash table control unit generates a second location in the hash table by adding a fixed offset to the first location when the MAC address and the VLAN id of the packet do not match one of the MAC addresses and one of the VLAN ids stored at the first location in the hash table, respectively.

8. The switch controller of claim 7, wherein the fixed offset is a prime number.

9. The controller of claim 1, wherein the hash table control unit provides at least an output port number of a port associated with the address and the VLAN id of the packet.

10. The switch controller of claim 1 further comprising a storage buffer including a multiplicity of contiguous buffers for temporarily storing the packet.

11. A method for operating a switch controller comprising:

providing a plurality of ports including at least one bus port associated with ports connected to other switch controllers in a network;

storing MAC addresses and VLAN ids of ports within the network in a hash table; and

hashing a MAC address and a VLAN id of a packet to identify a first location in the hash table.

12. The method of claim 11 further comprising storing, for each one of the VLAN ids stored in the hash table, one of the MAC addresses that identifies one of the other switch controllers having ports belonging to the one of the VLAN ids without identifying each one of the ports of the one of the other switch controllers that belongs to the one of the VLAN ids.

13. The method of claim 12 further comprising:

identifying the one of the switch controllers from the hash table based on the MAC address and the VLAN id of the packet; and

forwarding the packet to the one of the switch controllers.

14. The method of claim 11 further comprising generating the first location from the MAC address and the VLAN id using a hash function.

15. The method of claim 11 further comprising generating a second location in the hash table by adding a fixed offset to the first location when the MAC address and the VLAN id of the packet do not match one of the MAC addresses and one of the VLAN ids stored at the first location in the hash table, respectively.

16. The method of claim 15 further comprising generating the fixed offset, wherein the fixed offset includes a prime number.

17. The method of claim 11 further comprising providing at least an output port number of a port associated with the MAC address and the VLAN id of the packet.

18. The method of claim 11 further comprising temporarily storing the packet.

19. A local virtual local area network (VLAN) table for a network switch, the local VLAN table comprising:

a port membership for a VLAN identifier, wherein the port membership identifies ports of the network switch that are members of a VLAN identified by the VLAN identifier; and

a switch membership that identifies network switches that are members of the VLAN identified by the VLAN identifier.

20. A method for broadcasting a packet, the method comprising:

storing in a local virtual local area network (VLAN) table of a network switch,

a port membership for a first VLAN identifier, wherein the port membership identifies ports of the network switch that are members of a VLAN identified by the first VLAN identifier, and

a switch membership that identifies network switches that are members of the VLAN identified by the first VLAN identifier; and

determining which of the ports and the network switches in the local VLAN table correspond to a second VLAN identifier stored in the packet.

21. The method of claim 20 further comprising providing a copy of the packet to the ports and the network switches that correspond to the second VLAN identifier.