The bestroute best-external command enables a BGP device to select the sub-optimal route if the route preferentially selected based on BGP route selection rules is an IBGP route.
The undo bestroute best-external command restores the default configurations.
By default, Best External routes are not selected.
Usage Scenario
If master and backup PEs are deployed, routes are selected based on BGP route selection rules; if the primary link fails, the BGP route convergence takes a long time because no backup route is available. To address this problem, run the bestroute best-external command to enable a BGP device to select Best External routes if the route preferentially selected based on BGP route selection rules is an IBGP route.
Precautions
The bestroute best-external command only enables a BGP device to select Best External routes. To enable the BGP Best External function, you also need to run the peer advertise best-external command to enable the BGP device to advertise Best External routes to its peers.