A storage area network and method for defining a static Fibre Channel Fabric that does not require a Principal Switch. The storage area network comprises one or more hosts, one or more storage devices, and a static Fabric connecting the one or more hosts and storage devices. Within the static Fabric, the Switches have their Domain_ID and Fabric_Name statically set. The method comprises accessing the Fabric, selecting a Switch in the Fabric, and statically configuring the Domain_ID and Fabric_Name for the selected Switch. The above sequence is repeated for each Switch in the static Fabric. In one embodiment, after being statically configured, the Switch is isolated from any dynamically set Switches in the Fabric. The Switch detects which of its Ports are connected to dynamically set Switches, and then isolates them, while maintaining operational the Ports connected to statically configured Switches.
A method and apparatus for continuing the operation of a spanning tree protocol at a network device despite crashes or failures at that device is disclosed. The network device includes a plurality of line cards having ports for receiving and forwarding messages and a plurality of supervisor cards for processing at least some of those messages. Upon start-up, one of the supervisor cards is designated the active supervisor, while all other supervisor cards are designated standby supervisors. The active supervisor runs the spanning tree protocol (STP). The active supervisor informs the standby supervisors of the states of ports set by the STP. When a crash or failure occurs at the active supervisor, one of the standby supervisors is immediately designated to be the new active supervisor, and the new active supervisor uses the states of ports set by the original STP.
A method of managing a computer network switch is disclosed. The method has the steps of: setting a port of the switch to root guard protected status (RG status); selecting by a spanning tree protocol (STP) the port as a designated port; and setting said port into blocked status, in response to said port being both in root guard protected status and selected by STP as a root port. By setting a port to root guard protected, the port is prevented from becoming a designated port, and so then forcing the root port to remain in a desired core network.
A network device is configured in a manner to prevent connectivity loops such as one way connectivity loops. A user configures a port of the network device to have an associated state. The state indicates that the port is for communication up the spanning tree towards a root network device, or down the spanning tree away from the root network device. The spanning tree protocol is then executed and determines a role for the port. The role determined by the spanning tree protocol is compared to the user selected state, and if there is an inconsistency, for example one that would indicate a one way connectivity loop, the port is blocked.
An apparatus and method for preventing the disruption of Fibre Channel Fabrics caused by ReConfigure Fabric (RCF) messages is disclosed. The apparatus includes a storage area network and a plurality of Fibre Channel Switches arranged in a Fabric. Each of the plurality of Switches includes logic to selectively configure their Ports to either reject or accept RCF messages. When configured to reject RCF messages, the Switch Port that receives an RCF message will generate a reject message along with a reason code explanation "E_Port Isolated", and then transition into an Isolated state. When the Switch that generated the RCF message receives the reject message, its Port also transition into the Isolated state. In accordance with the method of the present invention, either a Storage Service Provider or a client can access the Switches of the Fabric through either a command line interpreter or a management application. Once access to the Fabric is established, the logic of the Ports of the Switches can be selectively configured to reject or accept RCF messages as described above.