Users Guide

Pre-Conguring a Stack Unit Slot
You may also pre-congure an empty stack unit slot with a logical stack unit.
To pre-congure an empty stack unit slot, use the following command.
• Pre-congure an empty stack unit slot with a logical stack unit.
CONFIGURATION mode
stack-unit unit_id provision S4820T
Example of Viewing a Logical Conguration of a Pre-Congured Stack Unit
After creating the logical stack unit, you can congure the interfaces on the stack unit as if it is present.
Dell#show system stack-unit 1
-- Unit 1 --
Unit Type : Member Unit
Status : not present
Dell#con
Dell(conf)#stack-unit 1 provision S4820T
Dell(conf)#end
Dell#show system stack-unit 1
-- Unit 1 --
Unit Type : Member Unit
Status : not present
Required Type : S4820T - 52-port GE/TE/FG (SE)
Dell#
Dell(conf)#interface tengigabitethernet 1/0
Dell(conf-if-te-1/0)#
Removing a Provisioned Logical Stack Unit
To remove the line card conguration, use the following command.
• To remove a logical stack-unit conguration, use the following command:
CONFIGURATION mode
no stack-unit unit_id provision
Hitless Behavior
Hitless is a protocol-based system behavior that makes a stack unit failover on the local system transparent to remote systems. The system
synchronizes protocol information on the Management and Standby stack units such that, in the event of a stack unit failover, it is not
necessary to notify the remote systems of a local state change.
Hitless behavior is dened in the context of a stack unit failover only.
• Only failovers via the CLI are hitless. The system is not hitless in any other scenario.
Hitless protocols are compatible with other hitless and graceful restart protocols. For example, if hitless open shortest path rst (OSPF) is
congured over hitless the link aggregation control protocol (LACP) link aggregation groups (LAGs), both features work seamlessly to
deliver a hitless OSPF-LACP result. However, to achieve a hitless end result, if the hitless behavior involves multiple protocols, all protocols
must be hitless. For example, if OSPF is hitless but bidirectional forwarding detection (BFD) is not, OSPF operates hitlessly and BFD aps
upon an RPM failover.
The following protocols are hitless:
High Availability (HA)
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