Understanding Automatic Switchover; Limitations Of Automatic Switchover; Understanding Reversion After Switchover; Table 3: Commands That Can Cause Automatic Switchover - Juniper JUNOSE SOFTWARE FOR E SERIES 11.3.X - SERVICE AVAILABILITY CONFIGURATION GUIDE 2010-10-08 Configuration Manual

JunosE 11.3.x Service Availability Configuration Guide

Understanding Automatic Switchover

Limitations of Automatic Switchover

Related
Documentation

Understanding Reversion After Switchover

12
Provided you have not issued the redundancy lockout command for the primary line
module, the router switches over to the spare line module automatically if it detects any
of the following failures on the primary line module:
Power-on self-test (POST) failure
Software-detected unrecoverable error
Software watchdog timer expiration
Primary line module failure to respond to keepalive polling from the SRP module
Removal, disabling, or reloading of the primary line module
Missing or disabled primary line modules when the router reboots
Resetting the primary line module using the concealed push button
If automatic switchover is enabled on a slot (the default configuration) and a spare line
module is available, issuing some CLI commands for the primary line module causes a
switchover (Table 3 on page 12).
You can also disable automatic switchover on individual slots. For more information, see
"Configuring Line Module Redundancy" on page 13.

Table 3: Commands That Can Cause Automatic Switchover

Command
slot disable primary-line-module-slot
reload slot primary-line-module-slot
Line Module Redundancy Overview on page 9
Understanding Reversion After Switchover on page 12
Configuring Line Module Redundancy on page 13
Managing Line Module Redundancy on page 13
You can install only one spare line module in the group of slots covered by the redundancy
midplane or redundancy group. If the router is using the spare line module, no redundancy
is available. Reverting to the primary module as soon as possible is desirable. By default,
the router does not automatically revert to the primary module after switchover; however,
Reason for Automatic Switchover
The command disables the primary line module
but not the primary I/O module or IOAs.
The command is equivalent to pushing the reset
button on the primary line module.
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