Users Guide

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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 29. Boot Code Requirements
Component Boot Code
S4820T 1 2.0.3
The features in this collection are:
• Component Redundancy
• Online Insertion and Removal
• 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.
RPM Redundancy
The current version of Dell Networking OS supports 1+1 hitless route processor module (RPM) redundancy.
The primary RPM performs all routing, switching, and control operations while the standby RPM monitors the primary RPM. In the
event that the primary RPM fails, the standby RPM can assume control of the system without requiring a chassis reboot.
This section contains the following sub-sections:
• Boot the Chassis with a Single RPM
• Boot the Chassis with Dual RPMs
• Automatic and Manual RPM Failover
• Support for RPM Redundancy by Dell Networking OS Version
• RPM Synchronization
Boot the Chassis with a Single RPM
You can boot the chassis with one RPM and later add a second RPM, which automatically becomes the standby RPM.
Dell Networking OS displays the following message when the standby RPM is online.
%RPM-2-MSG:CP0 %POLLMGR-2-ALT_RPM_STATE: Alternate RPM is present
%IRC-6-IRC_COMMUP: Link to peer RPM is up
%RAM-6-RAM_TASK: RPM1 is in Standby State.
High Availability (HA)
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