Constructing a New Stack from Scratch or Adding New Units to a Stack

Consider the following points when creating a new stack or adding new units to an existing stack.

• The easiest way to create a stack or to add units to a stack is to use the stack interactive-setup utility. The stack interactive-setup command provides two options. Option 2 is used to discover clean units. Option 3 can discover clean or non-clean units. For a definition of "clean unit," refer to Stacking terminology.
• If you are configuring a stack in a production system, RUCKUS recommends configuring spanning tree protocols (STP, RSTP or MSTP) on the active controller before making connections. You can enable either global STP or STP only on the default VLAN. If there are already loops in the system before you configure STP and if the looping packets have higher priority than the STP BPDU packets, STP may not converge. In this case, disable or disconnect the looping links to break the loops so that STP can converge. Then reenable or reconnect the links.
• From FastIron release 09.0.00, STP is enabled by default in router images in the default VLAN.
• If you are configuring a stack in a non-production system and you don't want to configure STP, the stack interactive-setup or stack zero-touch provisioning utility can discover new clean units under looping conditions.
• Make all connections before entering the stack interactive-setup command.
• RUCKUS recommends using stack interactive-setup option 2 to discover clean units.
• When a clean unit receives stack interactive-setup or stack zero-touch provisioning probes, it temporarily installs a filter to drop all traffic except protocol packets on every port to break possible loops in case STP is not enabled. As a result, a clean unit can be discovered by stack interactive-setup or stack zero-touch provisioning under looping conditions. The temporary filter exists only during the stack interactive-setup or stack zero-touch provisioning process. Once the process is completed, loops may recur if STP is not configured.
• Stack interactive-setup option 2 and stack zero-touch provisioning cannot detect non-clean units. Only stack interactive-setup option 3 can detect non-clean unit. However, option 3 may fail under looping condition.
• All loops disappear after the new units are discovered and reload to join the stack. The connected ports become stack-ports or stack-trunks.
• Be sure to enter the write memory command after new units join as stack members.