The value of tBgpInstanceAdvertiseExternal specifies
the address families which are enabled on this router instance
to advertise the best external route to the destination even when
its best overall route is an internal route.
An 'inconsistentValue' error is returned if an attempt is made to set
this object to a non-default value when the value of object
tBgpInstanceDisableClientReflect is set to 'false'.