Route preference (Administrative distance)

Junos OS assigns a default preference value (also known as an administrative distance) to each route that the routing table receives. The default value depends on the source of the route. The preference value is a value from 0 through 4,294,967,295 (232 ? 1), with a lower value indicating a more preferred route. You can modify the default value. 

Starting in 26.2, you can configure administrative distance (preferences) separately (internal or external) for BGP learned routes and corresponding paths.