Appendix: Cascade Connection

FC Switch Modules N8406-*** can be subjected to cascade connection with each other. The following describes the cascade feature of the FC Switch Module.

Cascade Connection

The cascade feature of the FC Switch Module is characterized as follows:

„The FC Switch Modules subjected to cascade connection can share the external devices connected to them.

„The FC Switch Modules subjected to cascade connection can share the CPU blade connected to each of the FC Switch Modules.

„Cascade connection of up to three hops is supported.

„Zoning can be provided among FC Switch Modules subjected to cascade connection.

„When a Fabric is constructed by cascading the FC Switch Modules, one of the FC Switch Modules in the Fabric operates as a Principal switch. A single FC Switch Module without cascading always operates a Principal switch.

„All FC Switch Modules except the Principal switch operate as Subordinate switches.

„ Any FC Switch Module in the Fabric can be set to be a Principal switch by “fabricprincipal” command.

„Cascading path between FC Switch Modules can be connected by multiple connections.

„Influence to the Fabric when a single cascading path failure occurred can be avoided by making cascading path redundant or routing path between FC Switch Modules redundant.

„The maximum transmission rate among FC Switch Modules subjected to

cascade connection is 4G bps per one cascade path.

„Any cascade connections of more than three hops are not supported.

„The FC Switch Module can make cascade connection with only

N8406-019/020. Cascade connection with any other FC switch is not supported.

„The FC Switch Modules in the same Blade Enclosure (SIGMABLADE) cannot make cascade connection with each other.

„The role of the FC Switch Module (Principal or Subordinate) may be changed by the Fabric reconstruction.

„When cascade connection is made, a Fabric construction process is done in the FC Switch Modules connected. Influence to I/O operation in the Fabric may occur during the Fabric construction process (including reconstruction process).

„A Fabric reconstruction process occurs if the Principal switch is removed from the Fabric by the cascading path failure.

„Even if the cascading path or routing path between FC Switch Modules is redundant, A Fabric reconstruction occurs at other switches if the Principal switch is removed from the Fabric when a failure occurs at the Principal switch.

„When setting of Zoning is done in the FC Switch Modules with cascading connection, the ports used for cascading path between FC Switch Modules must not be set zone. The cascading path is used by all zones. It may become a cause of failure of device recognition if setting of Zoning is done with the zone including the ports used for cascading path.

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