Which two statements best describe an OSPF deployment? (Choose two)
A.
ABR provides automatic classful network boundary summarization.
B.
ABR requires manual configuration for classful network summarization
C.
External routes are propagated into the autonomous system from stub areas via ASBR.
D.
External routes are propagated into the autonomous system from regular areas or NSSA via ASBR.
E.
External routes are propagated into the autonomous system from regular areas or NSSA via ABR.
Explanation:
Refer to the link below, the protocol is designed to function that way. Link: http://www.cisco.com/en/US/tech/tk365/technologies_white_paper09186a0080094e9e.shtml
The answer of the D is wrong because the external routes are filter from regular areas or NSSA via ABR…the ASBR is from external routes from other Autonomous systems runing EIGRP RIP.. othe rOSPF process or other protocol. so i pick up E instead of E
Regards.
D is incorrect. From the NSSA into the Regular areas is via ABR, hence E is the correct answer.
http://www.cisco.com/c/en/us/support/docs/ip/open-shortest-path-first-ospf/6208-nssa.html