RFC1583 vs. RFC2328


In OSPF External Routes , when the router choose based on

(the lowest area ID)

or based on (the Non-backbone area vs. backbone area vs. inter-area)

or based on the (lowest total cost to the ASBR/Forwarding address)

or based on the (lowest seed metric)

or based on (the formula in RFC 1583 which is X+Y)?

and does all these variations are done in RFC2328 ONLY ? or its done in both RFC 1583 and RFC 2328 ? and does these variations are done to the O Es ONLY ? or both to O Es and O Ns