Specify Whether the Route Is Permanently Installed in the Forwarding Table

By default, statically configured routes are deleted from the forwarding table when the routing protocol process shuts down normally. To have an IPv4 static route remain in the forwarding table, include the retain statement at the [edit routing-options static (defaults | route)]. Doing this greatly reduces the time required to restart a system
that has a large number of routes in its routing table.

[edit routing-options static (defaults | route)] 

retain; 

To have an IPv6 static route remain in the forwarding table, include the retain statement at the [edit routing-options rib inet6.0 static (defaults | route)] hierarchy level. Doing this greatly reduces the time required to restart a system that has a large number of routes in its routing table.

[edit routing-options rib inet6.0 static (defaults | route)] 

retain; 

To explicitly specify that IPv4 routes be deleted from the forwarding table, include the no-retain statement at the [edit routing-options static (defaults | route)]. Include this statement when configuring an individual route in the route portion of the static statement to override a retain option specified in the defaults portion of the statement.

[edit routing-options static (defaults | route)] 

no-retain; 

To explicitly specify that IPv6 routes be deleted from the forwarding table, include the no-retain statement at the [edit routing-options static (defaults | route)] hierarchy level. Include this statement when configuring an individual route in the route portion of the static statement to override a retain statement specified in the defaults portion of the statement.

[edit routing-options rib inet6.0 static (defaults | route)] 

no-retain;