Stack manager protocol with automatic set up mechanism
A stack switch for performing pass-through forwarding operations, assigning stack switch identifiers to a plurality of stack switches, temporarily disabling supervision messages exchanged by stack switches, and electing a primary master stack switch is disclosed. In the pass-through mode, the stack switch automatically forwards packets between stack ports independent of their destination address to maintain connectivity between adjacent stack switches while conventional bridging and routing operations are disabled. The sequential identifiers are also preferably assigned in accordance with the sequential position of the various stack switches to better reflect the topology of those switches. The switch is also preferably adapted to temporarily disable the transmission of supervision messages between stack switches to prevent re-assignment of network management functions when switch resources are low. The switch may execute a stack switch identifier numbering scheme based on the time the switch became operational.
1. A multi-layer stack switch system comprising a plurality of stack switches enabling the multi-layer stack switch system to emulate a single switching device, the plurality of stack switches comprising: one or more managed stack switches, wherein each of the one or more managed stack switches functions independently as an individual module and is adapted to transmit supervision messages as keep-alive indications, to invoke processes to verify an integrity of one or more of the plurality of stack switches, and to initiate actions to correct and update stack topology and stack element information to one or more of the plurality of stack switches, and
a primary master stack switch adapted to automatically transmit a supervision suspension message to temporarily prevent the one or more of the plurality of managed stack switches from expecting supervision messages from other stack switches, wherein the supervision suspension message is transmitted when an error has occurred and the primary master stack switch is preparing a postmortem file in anticipation of a shut-down and re-boot; wherein the supervision suspension message is automatically rescinded by the primary master after it completes the preparation of a postmortem file.
2. The stack switch system of claim 1 , wherein said one or more managed stack switches are adapted to select a new primary master stack switch if the current primary master stack switch fails to: transmit the supervision suspension message; and respond to one or more of the transmitted supervision messages.
3. The stack switch system of claim 1 , wherein the one or more managed stack switches are adapted to resume transmission of supervision messages after a predetermined period of time.
4. The stack switch system of claim 1 , wherein the one or more managed stack switches are adapted to resume transmission of supervision messages upon the expiration of a timeout parameter and upon rescission of the supervision suspension message.
5. The stack switch system of claim 1 , wherein the supervision messages comprises stack switch system topology information.
6. The stack switch system of claim 5 , wherein the stack switch system topology information comprises: an operational stack element identifier of an originating stack switch and an operational stack element identifier of primary master stack switch with respect to the originating stack switch.
7. The stack switch system of claim 1 , wherein the supervision messages communicate: insertion of a new stack switch into the stack switch system; modification of a physical connection between two of the plurality of stack switches; and communication failure between two of the plurality of stack switches.