What route selection rules should be followed when external routes with the same prefix are imported into OSPF on an S series switch

Question: What route selection rules should be followed when external routes with the same prefix are imported into an S series switch supporting OSPF?

Answer: Imported external OSPF routes include Type 1 and Type 2 routes. By default, Type 2 routes are imported.
When Type 1 external routes are imported, in route calculation, the cost of the route to be advertised is the sum of the LSA cost and the cost of an external route.
When Type 2 external routes are imported, OSPF considers that the cost of an external route is much higher than that of an intra-area route. Therefore, only the LSA cost value is used in route calculation.
When Type 1 external routes with the same prefix are imported, the route selection rules are as follows:
The route with the lowest cost is selected. The cost is the sum of the cost of the route to the ASBR and the LSA cost.
If the costs of the routes are the same, the route in a Type 5 LSA is selected.
When Type 2 external routes with the same prefix are imported, the route selection rules are as follows:
The imported route with the smallest LSA cost value is selected.
If the LSA cost values are the same, the route with the lowest cost of the route to the ASBR is selected.
If the costs of the routes are the same, the route in a Type 5 LSA is selected.

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