High Availability (Ha); Component Redundancy; Automatic And Manual Stack Unit Failover - Dell S4048–ON Configuration Manual

High Availability (HA)

High availability (HA) is supported on Dell Networking OS.
HA is a collection of features that preserves system continuity by maximizing uptime and minimizing packet loss during system
disruptions.
To support all the features within the HA collection, you should have the latest boot code. The following table lists the boot code
requirements as of this Dell Networking OS release.
Table 34. Boot Code Requirements
Component
S4048–ON
The features in this collection are:
•

Component Redundancy

• Hitless Behavior
• Graceful Restart
• Software Resiliency
• Hot-Lock Behavior
Component Redundancy
Dell Networking systems eliminate single points of failure by providing dedicated or load-balanced redundancy for each component.

Automatic and Manual Stack Unit Failover

Stack unit failover is the process of the standby unit becoming a management unit.
Dell Networking OS fails over to the standby stack unit when:
1. Communication is lost between the standby and primary stack unit.
2. You request a failover via the CLI.
To display the reason for the last failover, use the show redundancy command from EXEC Privilege mode.
Example of the show redundancy Command
Dell#show redundancy
-- Stack-unit Status --
------------------------------------------------
Mgmt ID:
Stack-unit ID:
Stack-unit Redundancy Role:
Stack-unit State:
Stack-unit SW Version:
Link to Peer:
Peer Stack-unit:
-- Stack-unit Redundancy Configuration --
Boot Code
1 2.0.3
0
0
Primary
Active
9.6(0.0)
Down
not present
20
341
High Availability (HA)