Port extender

Patent metadata

Field	Value
Publication number	US-9294396-B2
Application number	US-201313798010-A
Country	US
Kind code	B2
Filing date	Mar 12, 2013
Priority date	Mar 12, 2013
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

An extended bridge structure that includes a controlling bridge and port extenders is disclosed. A port extender according to some embodiments of the present invention includes a processor that processes receives packets in a way that executes at least one procedure that substitutes for a function of the controlling bridge. A controlling bridge according to the present invention provides data to the port extender that enables it to execute the at least one procedure that substitutes for a function of the controlling bridge.

First claim

What is claimed is:

1. A port extender, comprising:
access ports configured to exchange packets with nodes;
cascade ports configured to exchange packets with downstream port extenders;
uplink ports configured to exchange packets with upstream devices;
memory; and
a processor coupled to the memory, the access ports, the cascade ports, and the uplink ports, the processor executing a procedure stored in the memory comprising:
local switching;
performing a table lookup for a source media access control (MAC) address and a destination MAC address for a first packet received on one of the access ports;
forwarding the first packet to the destination MAC address when both the source and destination MAC addresses are found in the lookup table; and
when the source or destination MAC address is not found in the look up table, adding a first port extender tag with a source identifier (SRC) field set to the extended port associated with the access port and a destination identifier (DST) field set to 0 to form a tagged packet;
forwarding the tagged packet to the uplink port when either the source or destination MAC address is not found in the lookup table.

2. The port extender of claim 1 , wherein the procedure includes execution of an access control logic (ACL) and quality of service (QoS) function.

3. The port extender of claim 2 , wherein the ACL and QoS policies for one or more extended ports associated with the access ports or the cascade ports are received from a controlling bridge and stored in a table in the memory during an instantiation procedure.

4. The port extender of claim 1 , wherein the procedure includes
receiving a tagged packet on a cascade port, the tagged packet including a second source MAC address and a second destination MAC address and a second port extender tag that includes a SRC and a DST field;
performing a table lookup based on both the second source MAC address and the second destination MAC address;
if there is a hit on both the second source MAC address and the second destination MAC address, determining whether the second destination MAC address is associated with one of the access ports or one of the cascade ports, removing a tag from the tagged packet when the destination MAC address is one of the access ports, setting the DST field to a virtual port when the second destination MAC address is one of the cascade ports, and forwarding the tagged packet to the second destination MAC address;
if there is no hit on either the second source MAC address or the second destination MAC address, forwarding the tagged packet to the uplink port.

5. A controlling bridge, comprising:
at least one extended port associated with one or more extended ports;
a memory that stores tables; and
a processor coupled to the at least one extended port and the memory, the processor executing procedures that include adding entries to tables in at least one port extender that enables the at least one port extender to perform at least one procedure in place of the controlling bridge, wherein the procedure comprises
receiving a tagged packet on a cascade port, the tagged packet including a source MAC address and a destination MAC address and a port extender tag that includes a SRC and a DST field;
performing a table lookup based on both the source MAC address and the destination MAC address;
if there is a hit on both the source MAC address and the destination MAC address, determining whether the destination MAC address is associated with an access port or one of a plurality of cascade ports, removing a tag from the tagged packet when the destination MAC address is the access port, setting the DST field to a virtual port when the destination MAC address is one of the plurality of cascade ports, and forwarding the tagged packet to the destination MAC address;
if there is no hit on either the second MAC address or the destination MAC address, forwarding the tagged packet to an uplink port.

6. The controlling bridge of claim 5 , wherein the procedures include
receiving a second tagged packet from the at least one extended port, the second tagged packet including the source MAC address, the destination MAC address, a source address, and a destination address;
performing a lookup utilizing the source MAC address and the destination MAC address;
if there is no hit on the source MAC address, learning the source MAC address and forwarding the learned MAC address association with the source address to associated port extenders;
if there is no hit on the destination MAC address, flooding the packet on all ports of the controlling bridge;
if there is a hit on the destination MAC address, setting the destination address to an address indicated in the lookup and forwarding the tagged packet.

7. An extended bridge, comprising:
a controlling bridge, the controlling bridge including at least one extended port, a processor, and a table stored in a memory; and
at least one port extender, the at least one port extender coupled to the at least one extended port, the at least one port extender receiving table entries from the controlling bridge and performing at least one procedure in place of the controlling bridge the procedure comprising:
receiving a tagged packet on a cascade port, the tagged packet including a source MAC address and a destination MAC address and a port extender tag that includes a SRC and a DST field;
performing a table lookup based on both the source MAC address and the destination MAC address;
if there is a hit on both the source MAC address and the destination MAC address, determining whether the destination MAC address is associated with an access port or one of a plurality of cascade ports, removing a tag from the tagged packet when the destination MAC address is the access port, setting the DST field to a virtual port when the destination MAC address is one of the plurality of cascade ports, and forwarding the tagged packet to the destination MAC address;
if there is no hit on either the second MAC address or the destination MAC address, forwarding the tagged packet to an uplink port.

8. The extended bridge of claim 7 , wherein the at least one procedure includes executing ACL and QoS policies.

9. The extended bridge of claim 7 , wherein the at least one procedure includes switching packets.

10. The extended bridge of claim 7 , wherein the port extender supports multipathing.

11. The extended bridge of claim 7 , wherein multipathing includes source suppression.

12. A method of operating a port extender, comprising:
receiving, from a controlling bridge separate from the port extender, a procedure including at least one function of the controlling bridge;
receiving a tagged packet; and
processing the packet according to the at least one function as a substitute for the controlling bridge, the process comprising:
receiving the tagged packet on a cascade port, the tagged packet including a source MAC address and a destination MAC address and a port extender tag that includes a SRC and a DST field;
performing a table lookup based on both the source MAC address and the destination MAC address;
if there is a hit on both the source MAC address and the destination MAC address, determining whether the destination MAC address is associated with an access port or one of a plurality of cascade ports, removing a tag from the tagged packet when the destination MAC address is the access port, setting the DST field to a virtual port when the destination MAC address is one of the plurality of cascade ports, and forwarding the tagged packet to the destination MAC address;
if there is no hit on either the second MAC address or the destination MAC addres

Assignees

• Dell Products Lp

Inventors

• Sundaram Shivakumar
• Subramanian Krishnamurthy
• Ghanwani Anoop
• Janadhanan Pathangi Narasimhan
• Anamula Mohnish
• Jayakumar Raja

Classifications

• H04L45/02

  Topology update or discovery · CPC title

• H04L45/745

  Address table lookup; Address filtering · CPC title

• H04L45/74 Primary

  Address processing for routing · CPC title

• H04L12/4625 Primary

  Single bridge functionality, e.g. connection of two networks over a single bridge · CPC title

• H04L45/26

  Route discovery packet · CPC title