Exam 200-301 topic 1 question 384 discussion

Must be unique: – OSPF process ID – router ID – IP address Must match: – netmask – area ID – timers

you guys confuse people here. the giving answers are correct

OSPF Multicast Addresses: 224.0.0.5 (OSPF All Routers) 224.0.0.6 (OSPF All DR/BDR Routers) 224.0.0.10 (OSPF Hello packets for neighbor discovery) C. Routers with different OSPF process IDs will not form an OSPF adjacency. However, the process ID is not typically a direct factor in the initial adjacency formation. E. OSPF will still form a neighbor adjacency even if the Router IDs are the same. Unique RID recommended.

given answers are correct

What about A? They won't become neighbors if they are in different AS

D &E are correct

timers must match, router id must unique

answ: C,D,E

D and E

Area duplicate router ID %OSPF-4-DUP_RTRID1: Detected router with duplicate router ID 100.0.0.2 in area 0 Explanation—OSPF detected a router that has the same router ID in the area. Recommended Action—The OSPF router ID should be unique. Make sure all routers in the area have unique router ID.

b and C OSPF uses two IP multicast addresses on broadcast and point-to-point networks: 225.0. 0.5 for all OSPF routers and 224.0. 0.6 for all DR/BDR (designated router/backup designated router) routers. Using IP multicast addresses is more efficient than using broadcast addresses.

what is the correct answer?

224.0.0.10 is used by eigrp so CD are correct

B can also be correct. Needs to be checked out.