Extreme Networks ExtremeSwitching 5520 Series Hardware Installation Manual page 60

SummitStack Terms
Table 20: List of Stacking Terms (continued)
Term
Backup node
Standby node
Acquired node
Data ports
Failover
Hitless failover
Node address
Node role election
Node role election priority A priority assigned to each node, to be used in node role election. The
60 ExtremeSwitching 5520 Series Hardware Installation Guide
Description
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.
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.
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.
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.
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.
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.
The unique MAC address that is factory-assigned to each node.
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 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.
Building Stacks