Distributed port-blocking method

Abstract

A method of managing connectivity between an end-device and one of a plurality of bridging-devices connected to the end-device. The method includes transmitting test messages by each of the bridging-devices, transmitting test messages by the end-device, determining, in each of the bridging-devices, with which of the other devices there is an operative connection, based on the test messages the bridging-device receives and determining, in each of the bridging-devices, whether a port leading to the end-device should be in a forwarding or blocking state responsive to the determination of the operative connections.

1 . A device of a local area network, comprising: 
 at least one port through which the device sends test messages, used in determining the topology of the network, to one or more bridging-devices of the network; and    a processor which runs an IP stack but does not run a software of any port blocking method.    
     
     
         2 . A method of blocking ports to prevent formation of active loops in a network, comprising: 
 determining topology information of the network;    determining whether one or more specific ports of the network are currently active; and    determining which port should be active, based on the determined topology information and based on whether the one or more specific ports of the network are currently active.    
     
     
         3 . A method according to  claim 2 , wherein determining the topology information comprises transmitting test messages between devices of the network.  
     
     
         4 . A method according to  claim 3 , wherein determining the topology information comprises determining whether the transmitted test messages are received.  
     
     
         5 . A method according to  claim 3 , wherein transmitting the test messages comprises transmitting messages which include indication of the protocol state of one or more of the ports of the transmitting device.  
     
     
         6 . A method according to  claim 2 , wherein determining the topology information comprises determining whether the links to which the one or more ports lead, are operative.  
     
     
         7 . A method according to  claim 6 , wherein determining the topology information comprises receiving hardware indications on the operability the links to which the one or more ports lead.  
     
     
         8 . A method according to  claim 2 , wherein determining which port should be active comprises determining that a first port should be active only if all the other ports leading to the same device as the first port are not currently active.  
     
     
         9 . A method according to  claim 8 , wherein all the ports leading to the same device as the first port are ordered in a predetermined order and wherein determining which port should be active comprises determining that the first port should be active only if all the other ports higher than the first port in the predetermined order are not in a state indicating that the port is planning to be active.  
     
     
         10 . A method according to  claim 2 , wherein determining whether the one or more specific ports of the network are currently active comprises determining by a first device of the network whether at least one port of a second device of the network is active.  
     
     
         11 . A method of blocking ports to prevent formation of active loops in a network, comprising: 
 determining topology information of the network;    determining one or more parameters of the network;    blocking a first group of ports responsive to the determined one or more parameters of the network and responsive to the determined topology information;    changing at least one of the one or more parameters of the network responsive to the blocking of the first group of ports; and    determining whether to change the group of blocked ports responsive to the changed at least one of the one or more parameters.    
     
     
         12 . A method according to  claim 11 , wherein determining the topology information comprises determining whether one or more links of the network are operative.  
     
     
         13 . A method according to  claim 11 , wherein determining the one or more parameters of the network comprises determining weights of one or more links of the network.  
     
     
         14 . A method according to  claim 13 , wherein changing at least one of the one or more parameters of the network comprises changing the weight of at least one of the links of the network.  
     
     
         15 . A method according to  claim 14 , wherein changing the weight of the at least one of the links comprises reducing the weight of at least one currently active link of the network.  
     
     
         16 . A method according to  claim 11 , wherein determining the one or more parameters of the network comprises determining an activating priority order of a plurality of ports of the network.  
     
     
         17 . A method according to  claim 16 , wherein changing at least one of the one or more parameters of the network comprises changing the position of at least one of the plurality of ports in the activating priority order.  
     
     
         18 . A method according to  claim 17 , wherein changing the position of at least one of the plurality of ports in the activating priority order comprises moving a currently active port to the top of the priority order.  
     
     
         19 . A method according to  claim 11 , wherein determining the one or more parameters comprises transmitting test messages between devices of the network.  
     
     
         20 . A method according to  claim 19 , wherein transmitting the test messages comprises transmitting BPDUs.  
     
     
         21 . A method according to  claim 11 , wherein changing at least one of the one or more parameters of the network comprises reducing the number of possible operability changes which will change the group of blocked ports of the network by changing the at least one of the one or more parameters of the network.  
     
     
         22 . A method according to  claim 11 , wherein changing at least one of the one or more parameters of the network comprises preventing the group of blocked ports of the network from changing without a failure occurring on the connection of an active port by changing the at least one of the parameters.  
     
     
         23 . A method of blocking ports to prevent formation of active loops in a network, comprising: 
 blocking a first group of ports at a first time responsive to an operativeness state of the network; and    blocking a second group of ports different from the first group of ports, at a second time, while the network is in the same operativeness state as caused the blocking of the first group of ports.    
     
     
         24 . A method according to  claim 23 , wherein the operativeness state of the network comprises a state in which substantially all the elements of the network are operative.  
     
     
         25 . A method according to  claim 23 , comprising blocking the second group of ports responsive to a different operativeness state of the network than caused the blocking of the first group of ports and wherein blocking the second group of ports while the network is in the same operativeness state as caused the blocking of the first group of ports comprises not changing the group of blocked ports although the operativeness state of the network changed from the different operativeness state to the same operativeness state as caused the blocking of the first group of ports.  
     
     
         26 . A method according to  claim 23 , comprising transmitting, from a plurality of bridging-devices of the network, test messages which include indication of the current state of the ports of the transmitting bridging-device and wherein blocking the second group of ports comprises blocking the second group of ports rather than the first group of ports responsive to the transmitted test messages.  
     
     
         27 . A method according to  claim 23 , wherein the network includes a plurality of bridging-devices and wherein at least some of the plurality of bridging-devices change the state of a port from forwarding to blocking only if the port is inoperative or suspected as being inoperative.  
     
     
         28 . A device of a local area network, comprises: 
 a processor; and    at least one port which passes to the processor at least messages belonging to a plurality of different protocols and which does not forward any of the messages it receives through any other port of the device.    
     
     
         29 . A device according to  claim 28 , wherein the at least one port determines which messages are passed to the processor based on the destination address of the packets and wherein the at least one port passes to the processor messages of a plurality of different destination addresses.  
     
     
         30 . A device according to  claim 29 , wherein the at least one port passes to the processor messages of at least one address different from the standard STA BPDU address.  
     
     
         31 . A method according to  claim 28 , wherein the at least one port does not forward messages received through any of the other ports of the device.  
     
     
         32 . A device according to  claim 28 , wherein the at least one port does not match addresses to ports.  
     
     
         33 . A device according to  claim 28 , wherein the at least one port tags all untagged messages received by the at least one port as belonging to a VLAN to which none of the other ports of the device belong.