SummitStack Terms
List of Stacking Terms describes the terms used for the SummitStack feature. These terms are listed in the recommended reading sequence.
| Term | Description |
|---|---|
| Stackable switch | An ExtremeSwitching switch that provides two stacking ports and can participate in a stack. |
| Stacking port | A physical interface of a stackable switch that is used to allow the connection of a stacking link. Stacking ports are point-to-point links that are dedicated for the purpose of forming a stack. |
| Native stacking | A stacking configuration in which stack members are connected using either designated Ethernet data ports or dedicated stacking connectors. |
| Alternate stacking | A stacking configuration in which stack members are connected using 10-Gbps Ethernet data ports that have been configured for stacking. These ports are located either on the switch itself or on option cards installed on the rear of the switch. |
| Stacking link | A cable that connects a stacking port of one stackable switch to a stacking port of another stackable switch, plus the stacking ports themselves. |
| Node | A switch that runs the Switch Engine operating system and is part of a stack. Synonymous with stackable switch. |
| Stack | A set of stackable switches and their connected stacking links made with the intentions that: (1) all switches are reachable through their common connections; (2) a single stackable switch can manage the entire stack; and (3) configurable entities such as VLANs and link trunk groups can have members on multiple stackable switches. A stack consists of all connected nodes regardless of the state of the nodes. |
| Stack topology | A contiguously connected set of nodes in a stack that are currently communicating with one another. All nodes that appear in the show stacking command display are present in the stack topology. |
| Stack path | A data path that is formed over the stacking links for the purpose of determining the set of nodes that are present in the stack topology and their locations in the stack. Every node is always present in a stack path whether or not stacking is enabled on the node. |
| Control path | A data path that is formed over the stacking links that is dedicated to carrying control traffic, such as commands to program hardware or software image data for software upgrade. A node must join the control path to fully operate in the stack. A node that is disabled for stacking does not join the control path, but does communicate over the stack path. |
| Active node | A node that has joined the control path. The active node can forward the control path messages or can process them. It can also forward data traffic. Only an active node can appear as a card inserted into a slot when the show slot {slot {detail} | detail } command is executed on the primary node of the stack. |
| Active topology | A contiguous set of active nodes in a stack topology plus the set of stacking links that connect them. When an active topology consists of more than one node, each node in the active topology is directly and physically connected to at least one other node in the active topology. Thus, the active topology is a set of physically contiguous active nodes within a stack topology. |
| Candidate node | A node that is a potential member of an active topology, or an active node that is already a member of an active topology. A candidate node may or may not be an active mode – that is, it may or may not have joined the control path. |
| Node role | The role that each active node plays in the stack – either primary, backup, or standby. |
| Primary node | The node that is elected as the primary node in the
stack. The primary node runs all of the configured control protocols
such as OSPF (Open Shortest Path First), RIP (Routing Information
Protocol), Spanning Tree, and EAPS (Extreme Automatic Protection
Switching). The primary node controls all of its own data ports as well as all data ports on the backup and standby nodes. To accomplish this, the primary node issues specific programming commands over the control path to the backup and standby nodes. |
| Backup node | The node assigned to take over the role of primary if the
primary node fails. The primary node keeps the backup node's databases
synchronized with its own databases in preparation for such an event.
If and when the primary node fails, the backup node becomes the primary node and begins operating with the databases it has previously received. In this way, all other nodes in the stack can continue operating. |
| Standby node | A node that is prepared to become a backup node in the
event that the backup node becomes the primary node. When a backup node
becomes a primary node, the new primary node synchronizes all of its
databases to the new backup node. When a node operates in a standby role, most databases are not synchronized – except those few that directly relate to hardware programming. |
| Acquired node | A standby or backup node that is acquired by a primary node. This means that the primary node has used its databases to program the hardware of the standby or backup node. Th |