Stackable switch |
An ExtremeSwitching or Summit
family 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 port |
A stacking port that can be used
only for connections between stacked switches, not for data
connections. |
Alternate port |
A port that can be used for either
stack connections or data connections. |
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 ExtremeXOS
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 master 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 master (or primary), backup, or standby.
|
Master node |
The node that is elected as the
master (or primary) node in the stack. The master node runs all of the
configured control protocols such as OSPF, RIP, Spanning Tree, and EAPS.
The master node controls all of its own data
ports as well as all data ports on the backup and standby nodes. To
accomplish this, the master 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 master if the master node fails. The master node keeps the
backup node's databases synchronized with its own databases in
preparation for such an event. If and when the
master node fails, the backup node becomes the master 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 master node.
When a backup node becomes a master node, the new master 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 master node. This means that the master node has used its
databases to program the hardware of the standby or backup node. The
standby or backup node has acted as a hardware programming proxy,
accepting the instructions of the master node to do so. An acquired backup node maintains the databases
needed to reflect why the hardware is programmed as it is. However,
a standby node does not. An acquired node can be re-acquired
(without a reboot) by the backup node only when the backup node
becomes the master node, and only when both the backup and standby
nodes were already acquired by the same master node at the time of
its failure.
|
Data ports |
The set of ports on a stackable
switch that are available for connection to your data networks. Such
ports can be members of a user-configured VLAN or trunk group. They can
be used for Layer 2 and 3 forwarding of user data traffic, for
mirroring, or other features you can configure. Data ports are different
from stacking ports. |
Failover |
The process of changing the backup
node to the master node when the original master node has failed. When a master node fails, if a backup node is
present, and if that node has completed its initial synchronization
with the master node, then the backup node assumes the role of
master node. The standby nodes continue their operation and their
data ports do not fail.
|
Hitless failover |
A failover in which all data ports
in the stack, except those of the failing master node, continue normal
operation when the master node fails. |
Hitless upgrade |
An operation in which the software
image is upgraded, and the new image begins executing, without
interrupting data traffic and without forcing any network reconvergence.
This ExtremeXOS software version does not support
hitless upgrade for a stack. |
Node address |
The unique MAC address that is
factory-assigned to each node. |
Node role election |
The process that determines the
role for each node. The election takes place during initial stack
startup and elects one master node and one backup node. An election also
takes place after a master node failover, when a new backup node is
elected from the remaining standby nodes. |
Node role election
priority |
A priority assigned to each node,
to bee used in node role election. The node with the highest node role
election priority during a role election becomes the master node. The
node with the second highest node role election priority becomes the
backup. |
Operational node |
A node that has achieved
operational state as a card in a slot. The operational state can be
displayed using the show slot
{slot {detail} | detail }command.
|
System uptime |
The amount of time that has passed
since the last node role election. You can display the system uptime by
entering the show switch {detail } command
on the master node. |
Stack segment |
A collection of nodes that form a
stack topology. The term is useful when a stack is severed. Each severed
portion of the stack is referred to as a stack segment. |
Stack state |
A state assigned by the stack to a
node. You can display the stack state by entering the show stacking
command. |
Easy Setup |
A procedure that automatically
configures the essential stacking parameters on every node for initial
stack deployment, and then automatically reboots the stack to put the
parameters into effect. The choice to run Easy
Setup is offered when you run the enable stacking {node-address
node-address}
command and the essential stacking parameters are unconfigured or
inconsistent. It can also be invoked directly by running the configure stacking
easy-setup command.
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