Chassis Redundancy in Juniper

Juniper can be have dual routing-engine, it can be maintenance router always running even one of routing-engine is failed to operation. But in case if you want to change one routing-engine failed be carefull to make sure routing-engine master is disabled chassis redundancy, it is not mandatory but is better yo always disabled before you unplug failed and plug good routing-engine. Why ?


Example case :
RE0 : master
RE1 : backup


- chassis redundancy enabled


- RE0 failed, so RE1 now as master
- RE0 -> change routing-engine
- RE0 still as backup


- make sure RE1 is chassis redundancy disabled


> configure
# deactivate chassis redundancy
...


> show configuration chassis redundancy 
##
## inactive: chassis redundancy
##
failover {
    on-loss-of-keepalives;
    on-disk-failure;
}
graceful-switchover;


? Because if RE1 chassis redundancy enabled, when plug good routing-engine in RE0, RE0 will automaticly get configuration from RE1 (master).


It will not be service impact, but for safety procedure, better to disabled it.