show stacking

show stacking


The show stacking command shows a summary of the nodes in the stack topology.

The show stacking command shows all nodes that are in the stack topology.

Syntax Description

This command has no arguments or variables.


There is no default value for this command.

Usage Guidelines

The asterisk (*) that precedes the node MAC address indicates the node on which this command is being executed, that is, the node to which the user is logged in.

The node MAC address is the address that is factory assigned to the stackable.

The slot number shown is the number currently in use by the related node. Since slot number configuration only takes effect during node initialization, a change in configured value alone does not cause a change to the slot number that is in use. Slot numbers show as hyphen (-) characters on nodes that have stacking disabled.

The Stack State shows the state values.

The Role is one of the following: Master, Backup, Standby, or none.

In a ring topology, the node on which this command is executed is always the first node displayed. The order of the nodes shown in the display is the order of their physical connection in the ring.

Even though the stack topology can be a ring, the active topology can simultaneously be a daisy chain because it is only a proper subset of the stack topology. If the node on which this command is executed is not active, the line

Active Topology is a ___

is replaced by the line

This node is not in an Active Topology.

The daisy chain topology is displayed in the order of physical connection. The master node detects the two nodes in the stack topology that have only one operating link, and these nodes become the ends of the stack. Such nodes always display at the top and bottom of the output.

It is possible for a node to be in Stabilizing or Waiting state and still be in the active topology. This is because it is possible for an active node to move to these states when a topology change is detected. Once a node becomes active, the node remains an active node until it reboots or an overflow condition occurs.

The Flags have the following definitions:
  • The C flag indicates that the related node is a candidate for membership of the same active topology to which the node on which the command is executed would belong.

  • The A flag indicates that the related node is an active node in the active topology of which the node on which the command is run is also a candidate node. Being an active node is necessary but not sufficient for presence of the node in a slot. Once the node has fully initialized, the active node appears as Present in the show slot display.

  • The O flag indicates that the related node is probably an active node in an active topology for which the node on which this command is being run is not a candidate.

The O flag is useful for the case where there is an inhibited link or a disabled or failed node that separates two active topologies. One active topology may contain the local node, and all other nodes in this active topology do not have the O flag set. All nodes that are members of an active topology that is separated by an inhibited link from the active topology that contains the local node have only the O flag set. All possibly active nodes have the O flag set if the local node is not a member of any active topology. For any node for which the O flag is set, the C and A flags are not set and vice-versa.

The following information is displayed:
  • Stack Topology is a ring or daisy-chain.

  • Active Topology is a ring or daisy-chain (or This node is not in an Active Topology.).

  • For each node:
    • Node MAC address (factory assigned).

    • Slot number in use.

    • Stack State:

      • Disabled - Node is not configured for stacking.

      • Failed - Node can't come up in the stack because it has a duplicate slot number.

      • Overflow - The node has detected that there are more nodes in the stack topology than are allowed.

      • Listening - Initial state when attempting to join the stack. The node is checking to see if its configured slot number duplicates that of another node. The node cannot be an active node in this state.

      • Stabilizing - Node is waiting until it sees no new topology changes. The node may or may not be an active node in this state.

      • Waiting - Topology has stabilized, if the active topology is to be a ring, and stacking link blocking is being performed. The node may or may not be an active node in this state.

      • Active - The node is an active node and is fully programmed to operate in the active topology.

  • Node role (master, backup, standby, or other transient node state).

  • Flags describing the node's membership in the active topology.

  • Whether or not the node is this node, that is, the node on which the command is run.


The following example shows the output of show stacking command:

Slot-1 Stack.30 # show stacking
Stack Topology is a Ring
Active Topology is a Daisy-Chain
Node MAC Address    Slot  Stack State  Role     Flags
------------------  ----  -----------  -------  ---
*00:04:96:26:60:DD  1     Stabilizing  Master   CA-
00:04:96:26:60:EE  4     Stabilizing  Standby  C--
00:04:96:26:60:FF  -     Disabled     Master   ---
00:04:96:26:60:AA  -     Disabled     Master   ---
00:04:96:26:60:88  -     Disabled     Master   ---
00:04:96:26:60:99  -     Disabled     Master   ---
00:04:96:26:60:BB  2     Stabilizing  Standby  C--
00:04:96:26:60:CC  3     Active       Backup   CA-
(*) Indicates This Node
Flags: (C) Candidate for this active topology, (A) Active node,
(O) node may be in Other active topology
Slot-1 Stack.31 #


This command was first available in ExtremeXOS 12.0.

Platform Availability

This command is available with all licenses and platforms that support the SummitStack feature. For information about which licenses and platforms support the SummitStack feature, see the Feature License Requirements document.