Forwarding table minimisation in ethernet switches

Abstract

An Ethernet switch for use in an Ethernet network comprises a set of ingress ports for receiving data frames and a set of egress ports. A memory is associated with each ingress port and stores forwarding information indicating one or more of the egress ports to which data frames received by that ingress port should be forwarded. A control or management interface receives information about a network connection established, or to be established, through the switch. A switch controller causes forwarding information to be stored in a memory associated with a first ingress port which the network connection will use, on the basis of the received information about a network connection. Forwarding information is not stored in a memory associated with a second of the set of ingress ports which the network connection will not use. Preferably, the switch controller causes forwarding information to be stored only in a memory associated with the first ingress port which the network connection will use and not to be stored in a memory associated with any of the other ingress ports.

1 - 17 . (canceled) 
     
     
         18 . A method of storing forwarding information in an Ethernet switch, the Ethernet switch being on a path determined for an Ethernet connection established through an Ethernet network comprising the Ethernet switch, the Ethernet connection being established using a control or management plane of the Ethernet network, the Ethernet switch comprising a plurality of ingress ports and a plurality of egress ports, each ingress port having a respective associated local forwarding database (FDB) for storing forwarding information to be used for forwarding packets received at the ingress port, the method comprising:
 determining a particular ingress port of the Ethernet switch to be used for receiving packets associated with the established Ethernet connection; and   storing Ethernet forwarding information for the established Ethernet connection in the local FDB to be used by the particular ingress port for forwarding received packets associated with the established Ethernet connection while not storing Ethernet forwarding information for the established connection in local FDBs to be used by other ingress ports of the Ethernet switch for forwarding packets.   
     
     
         19 . The method of  claim 18 , wherein determining a particular ingress port of the Ethernet switch to be used for receiving packets associated with the established Ethernet connection comprises identifying the particular ingress port to be used for forwarding received packets associated with the established Ethernet connection based on information associated with the established Ethernet connection received by the Ethernet switch. 
     
     
         20 . The method of  claim 18 , wherein the stored forwarding information comprises a destination MAC address associated with the established Ethernet connection and a Virtual Local Area Network (VLAN) identifier associated with the established Ethernet connection. 
     
     
         21 . The method of  claim 18 , wherein the stored Ethernet forwarding information comprises at least part of a Multi-Protocol Label Switching (MPLS) label. 
     
     
         22 . The method of  claim 18 , wherein the stored Ethernet forwarding information comprises at least one egress port of the plurality of egress ports of the Ethernet switch, the at least one egress port being associated with the established Ethernet connection. 
     
     
         23 . The method of  claim 18 , wherein:
 a combination of a first VLAN tag and a first destination MAC address identifies the established Ethernet connection in the local FDB to be used by the particular ingress port; and   a combination of a second VLAN tag and the first destination MAC address in the local FDB identifies another network connection in the local FDB to be used by the particular ingress port.   
     
     
         24 . The method of  claim 18 , further comprising:
 performing Ethernet learning of forwarding information at ingress ports of the Ethernet switch based on source addresses of packets received at the respective ingress ports; and   replicating forwarding information learned at the respective ingress ports at other ingress ports of the Ethernet switch while not replicating stored forwarding information for established Ethernet connections.   
     
     
         25 . A method of storing forwarding information for an Ethernet connection established in an Ethernet network by a control or management plane of the Ethernet network, the Ethernet network comprising a plurality of interconnected Ethernet nodes, each Ethernet node having a plurality of ingress ports and a plurality of egress ports, the method comprising:
 determining a path for the established Ethernet connection through nodes of the Ethernet network; and   in at least one Ethernet node on the path, the at least one Ethernet node comprising a plurality of ingress ports, each ingress port having a respective local forwarding database (FDB) for storing local forwarding information to be used by that ingress port:
 determining a particular ingress port of the Ethernet node to be used for receiving packets associated with the established Ethernet connection; and 
 storing forwarding information for the established Ethernet connection in the local FDB to be used by the particular ingress port for forwarding received packets associated with the established Ethernet connection while not storing Ethernet forwarding information for the established connection in local FDBs to be used by other ingress ports of the Ethernet node for forwarding packets. 
   
     
     
         26 . The method of  claim 25 , wherein the stored forwarding information comprises a destination MAC address associated with the established Ethernet connection and a Virtual Local Area Network (VLAN) identifier associated with the established Ethernet connection. 
     
     
         27 . The method of  claim 25 , wherein the stored forwarding information comprises at least one egress port of the plurality of egress ports of the Ethernet node which is associated with the established Ethernet connection. 
     
     
         28 . The method of  claim 25 , wherein:
 a combination of a first VLAN tag and a first destination MAC address identifies the established Ethernet connection in the local FDB to be used by the particular ingress port; and   a combination of a second VLAN tag and the first destination MAC address in the local FDB identifies another network connection in the local FDB to be used by the particular ingress port.   
     
     
         29 . The method of  claim 28 , further comprising:
 performing Ethernet learning of forwarding information at respective ingress ports of the Ethernet nodes based on source addresses of packets received at the respective ingress ports; and   replicating forwarding information learned at the respective ingress ports at other ingress ports of the same Ethernet nodes while not replicating stored forwarding information for the established connections in local FDBs to be used by other ingress ports of the Ethernet node for forwarding packets.   
     
     
         30 . An Ethernet switch, for use on a path determined for an Ethernet connection established through an Ethernet network comprising the Ethernet switch, the Ethernet connection being established using a control or management plane of the Ethernet network, the Ethernet switch comprising:
 a plurality of ingress ports, each ingress port having a respective associated local forwarding database (FDB) for storing forwarding information to be used for forwarding packets received at the ingress port;   a plurality of egress ports; and   at least one port controller adapted to store Ethernet forwarding information for the established Ethernet connection in a local FDB to be used by a particular ingress port to be used for forwarding received packets associated with the established Ethernet connection while not storing Ethernet forwarding information for the established connection in local FDBs to be used by other ingress ports of the Ethernet switch for forwarding packets.   
     
     
         31 . The Ethernet switch of  claim 30 , wherein the port controller is adapted to identify the particular ingress port to be used for forwarding received packets associated with the established Ethernet connection based on received information associated with the established Ethernet connection. 
     
     
         32 . The Ethernet switch of  claim 30 , wherein the stored forwarding information comprises a destination MAC address associated with the established Ethernet connection and a Virtual Local Area Network (VLAN) identifier associated with the established Ethernet connection. 
     
     
         33 . The Ethernet switch of  claim 30 , wherein the stored Ethernet forwarding information comprises at least part of a Multi-Protocol Label Switching (MPLS) label. 
     
     
         34 . The Ethernet switch of  claim 30 , wherein the stored Ethernet forwarding information comprises at least one egress port of the plurality of egress ports of the Ethernet switch, the at least one egress port being associated with the established Ethernet connection. 
     
     
         35 . The Ethernet switch of  claim 30 , wherein:
 a combination of a first VLAN tag and a first destination MAC address identifies the established Ethernet connection in the local FDB to be used by the particular ingress port; and   a combination of a second VLAN tag and the first destination MAC address in the local FDB identifies another network connection in the local FDB to be used by the particular ingress port.   
     
     
         36 . The Ethernet switch of  claim 30 , wherein the at least one port controller is adapted to:
 perform Ethernet learning of forwarding information at ingress ports of the Ethernet switch based on source addresses of packets received at the respective ingress ports; and   replicate forwarding information learned at the respective ingress ports at other ingress ports of the Ethernet switch while not replicating stored forwarding information for established Ethernet connections.   
     
     
         37 . An Ethernet switch, for use on a path determined for an Ethernet connection established through an Ethernet network comprising the Ethernet switch, the Ethernet connection being established using a control or management plane of the Ethernet network, the Ethernet switch comprising:
 a plurality of ingress ports, each ingress port having a respective associated local forwarding database (FDB) for storing forwarding information to be used for forwarding packets received at the ingress port;   a plurality of egress ports; and   at least one port controller adapted to store forwarding information for the established Ethernet connection in the local FDB to be used by the particular ingress port for forwarding received packets associated with the established Ethernet connection while not storing Ethernet forwarding information for the established connection in local FDBs to be used by other ingress ports of the Ethernet switch for forwarding packets.   
     
     
         38 . The Ethernet switch of  claim 37 , wherein the stored forwarding information comprises a destination MAC address associated with the established Ethernet connection and a Virtual Local Area Network (VLAN) identifier associated with the established Ethernet connection. 
     
     
         39 . The Ethernet switch of  claim 37 , wherein the stored forwarding information comprises at least one egress port of the plurality of egress ports of the Ethernet node which is associated with the established Ethernet connection. 
     
     
         40 . The Ethernet switch of  claim 37 , wherein:
 a combination of a first VLAN tag and a first destination MAC address identifies the established Ethernet connection in the local FDB to be used by the particular ingress port; and   a combination of a second VLAN tag and the first destination MAC address in the local FDB identifies another network connection in the local FDB to be used by the particular ingress port.   
     
     
         41 . The Ethernet switch of  claim 40 , wherein the at least one port controller is adapted to:
 perform Ethernet learning of forwarding information at respective ingress ports of the Ethernet nodes based on source addresses of packets received at the respective ingress ports; and   replicate forwarding information learned at the respective ingress ports at other ingress ports of the same Ethernet nodes while not replicating stored forwarding information for the established connections in local FDBs to be used by other ingress ports of the Ethernet node for forwarding packets.