BGP show commands display the following information for this feature:
For each RIB-IN entry in the output of the show router bgp routes prefix hunt command there is a Flags field that indicates the origin of the route and whether it is valid, best, used, and so on. This feature reflects an ‟Advertised” value in the Flags field. This indicates that the route was advertised to one or more peers. If the ‟Advertised” flag is present but the ‟Best” flag is not the operator can determine that the route was probably a best-external.
The show router bgp neighbor advertised-routes command displays all advertised routes to that peer, including routes that were overall best, best-external and best-internal.
The advertise-external configuration (specifically the address families for which it is enabled) is displayed as part of the show router bgp output.
Note that the overall best, best-external, and best-internal routes for a prefix can be determined from the output of the show router bgp routes prefix command. The first external route to be displayed in the output is always be the best-external route and the first internal route to be displayed in the output is always be the best-internal route. Only one of these routes will have the ‟Best” flag set, and this will be the overall best route.