By default, RIPng does not export routes it has learned to its neighbours. To have RIPng export routes, apply one or more export policies. To apply export policies and to filter routes being exported from the local router to its neighbors, include the export statement and list the name of the policy to be evaluated.

You can define one or more export policies. If no routes match the policies, the local router does not export any routes to its neighbors. Export policies override any metric values determined through calculations involving the metric-in (see above) and metric-out values.

If you configure an export policy, RIPng exports routes it has learned to the neighbours configured with the neighbor statement.

If a route being exported was learned from a member of the same RIPng group, the metric associated with that route (unless modified by an export policy) is the normal RIPng metric. For example, a RIPng route with a metric of 5 learned from a neighbor configured with a metric-in value of 2 is advertised with a combined metric of 7 when advertised to RIPng neighbors in the same group. However, if this route was learned from a RIPng neighbor in a different group or from a different protocol, the route is advertised with the metric value configured for that group with the metric-out statement. The default value for metric-out is 1.

By default, the JunOS software assigns a preference of 100 to routes that originate from RIPng. When the JunOS software determines a route’s preference to become the active route, the software selects the route with the lowest preference and installs this route into the forwarding table.

To modify the default RIPng preference value, include the preference statement, which can be a value from 0 through 4,294,967,295 (232 - 1).