https://www.juniper.net/documentation/en_US/junos/topics/concept/ex-series-high-availability.html
VRRP
Graceful Protocol Restart
Redundant Routing Engines
Virtual Chassis
Graceful Routing Engine Switchover
Link Aggregation
Nonstop Active Routing and Nonstop Bridging
Nonstop Software Upgrade
Redundant Power System