Question

A service provider redistributes external routes into OSPF at two ASBRs. ASBR1 advertises prefix 203.0.113.0/24 as an E2 (Type 5) route with metric 20. ASBR2 advertises the same prefix as an E1 (Type 5) route with metric 100, and the internal cost to reach ASBR2 is 30. An internal router has an internal cost of 50 to reach ASBR1. Which route does the internal router install, and why?

Accepted Answer

The E1 route via ASBR2, because OSPF always prefers E1 over E2 regardless of metric

Answer

The E2 route via ASBR1, because E2 external metric (20) is lower than the E1 route's external metric (100)

Answer

The E1 route via ASBR2, because its total cost (100 + 30 = 130) is compared and the E1 route type is preferred over E2 as a tiebreaker only

Answer

The E2 route via ASBR1, because both routes are equal cost and ASBR1 has the lower router ID