Service Manual

Table Of Contents
20
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 Boot Code
S4048–ON 1 2.0.3
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: 0
392
High Availability (HA)