Brocade traditional stacking terminology

Certain terms and roles specific to stacking are used throughout this guide. This section describes the roles stack units may assume as well as terms key to understanding stacking.

Refer to the Brocade FastIron Switch Port Extender Configuration Guide for terms specific to IEEE 802.1br and switch port extender (SPX) capability.

Stack unit roles

  • Active controller - Handles stack management and configures all system- and interface-level features.
    • Future active controller - The unit that will take over as active controller after the next reload, if its priority has been changed to the highest priority. When a priority for a stack unit is changed to be higher than the existing active controller, the takeover does not occur immediately to prevent disruptions in stack operation.
  • Standby controller - The stack member with the highest priority after the active controller. The standby controller takes over if the current active controller fails.
  • Stack member - A unit functioning in the stack in a capacity other than active controller or standby controller.
  • Stack unit - Any device functioning within the stack, including the active controller and standby controller.
    • Upstream stack unit - An upstream unit is connected to the first stacking port on the active controller. (The left port as you face the stacking ports.)
    • Downstream stack unit - A downstream unit is connected to the second stacking port on the active controller. (The right port as you face the stacking ports.)
The terms "upstream port" and "downstream port" have special meanings in an 802.1br SPX configuration. Refer to the Brocade FastIron Switch Port Extender Configuration Guide for more information.

Stacking terms

  • Bootup role - The role a unit takes during the boot sequence. This role can be standalone, active controller, standby controller, or stack member. The active controller or a standalone unit can access the full range of the CLI. Until a stack is formed, the local consoles on the standby controller and stack members provide access to a limited form of the CLI, such as the show stack and a few debug commands. When the stack is formed, all local consoles are directed to the active controller, which can access the entire CLI. The last line of output from the show version command indicates the role of a unit (except for standalone units) as shown in the following example:
  My stack unit ID = 1, bootup role = active
  • Clean unit - A unit that contains no startup flash configuration or runtime configuration. To erase old configuration information, enter the erase startup-config command and reset the unit.
  • Control path - A path across stacking links dedicated to carrying control traffic such as commands to program hardware or software image data for upgrades. A stack unit must join the control path to operate fully in the stack.
  • Default ports - FastIron devices use the default-ports command to define stacking port candidates.
  • Dynamic configuration - A unit configuration that is dynamically learned by a new stack unit from the active controller. A dynamic configuration disappears when the unit leaves the stack.
  • Interprocessor Communications (IPC) - The process by which proprietary packets are exchanged between stack unit CPUs.
  • IronStack - A set of Ruckus stackable units (maximum of twelve) and their connected stacking links so that all units can be accessed through their common connections. A single unit can manage the entire stack, and configurable entities, such as VLANs and trunk groups, can have members on multiple stack units.
  • Non-Functioning stack unit - A stack unit that is recognized as a stack member, and is communicating with the active controller over the Control Path, but is in a non-functioning state. A non-functioning stack unit will drop or discard traffic from non-stacked ports. This may be caused by an image or configuration mismatch.
  • Reserved / provisional unit - A unit configuration number that has no physical unit associated with it.
  • Secure-setup - A software utility that establishes a secure stack.
  • Sequential connection - Stack unit IDs, beginning with the active controller, are sequential. For example, 1, 3, 4, 6, 7 is sequential if active controller is 1. 1, 7, 6, 4, 3 are non-sequential in a linear topology, but become sequential in a ring topology when counted from the other direction as: 1, 3, 4, 6, 7. Gaps in numbering are allowed.
  • Stack path - A data path formed across the stacking links to determine the set of stack members that are present in the stack topology, and their locations in the stack.
  • Stack slot - A slot in a stack is synonymous with a line model in a chassis.
  • Stack topology - A contiguously-connected set of stack units in an IronStack that are currently communicating with each other. All units that are present in the stack topology appear in output from the show stack command.
  • Stacking link - A cable that connects a stacking port on one unit to a stacking port on another unit.
  • Stacking port - A physical interface on a stack unit that connects a stacking link. Stacking ports are point-to-point links that exchange proprietary packets. Stacking ports cannot be configured for any other purpose while operating as stacking ports. The number of available stacking ports depends on the platform. Some ports can be configured as either stacking ports or regular data ports. Refer to the hardware installation guide for the specific device for more information.
  • Standalone unit - A unit that is not enabled for stacking, or an active controller without any standby controller or stack members.
  • Static configuration - A configuration that remains in the database of the active controller even if the unit it refers to is removed from the stack. Static configurations are derived from the startup configuration file during the boot sequence, are manually entered, or are converted from dynamic configurations after a write memory command is issued.
  • Trunked stacking port (trunk) - A trunk consists of multiple stacking ports and is treated as one logical link. It provides more bandwidth and better resilience than individually connected ports.
  • Unit replacement - The process of swapping out a unit with a clean unit. No configuration change is required.