問題文
An engineer who is comfortable with OSPFv2 is asked to explain how OSPFv3 differs from it. Which statement about OSPFv3 is correct?
選択肢
- OSPFv3 forms its adjacencies per link rather than per subnet, and it identifies separate protocol instances on the same link so that several can coexist there.
- OSPFv3 numbers its protocol instances per area rather than per link, and it selects routes from the list of domains that a prefix has traversed so that loops are avoided.
- OSPFv3 keeps the same packet types rather than new ones, and it carries the whole topology description inside its hello packets so that a separate exchange is redundant.
- OSPFv3 forms its adjacencies per subnet rather than per link, and it drops the concept of areas so that every router in the domain holds a flat description.