How will router R2 be affected by the configuration of R1 that is shown in the exhibit?

Refer to the exhibit.

Assume that all of the router interfaces are operational and configured correctly.

How will router R2 be affected by the configuration of R1 that is shown in the exhibit?
A . Router R2 will not form a neighbor relationship with R1.
B . Router R2 will obtain a full routing table, including a default route, from R1.
C . R2 will obtain OSPF updates from R1, but will not obtain a default route from R1.
D . R2 will not have a route for the directly connected serial network, but all other directly connected networks will be present, as well as the two Ethernet networks connected to R1.

View Answer

Answer: A

Explanation:

Open Shortest Path First

http://en.wikipedia.org/wiki/Open_Shortest_Path_First

The configuration of R1 shows "router ospf 1" however, the diagram also shows that both routers should be in the backbone OSPF Area of "0". When routers are in different OSPF areas they will not form a neighbor relationship.

Neighbor relationships

As a link state routing protocol, OSPF establishes and maintains neighbor relationships in order to exchange routing updates with other routers. The neighbor relationship table is called an adjacency database in OSPF.

Provided that OSPF is configured correctly, OSPF forms neighbor relationships only with the routers directly connected to it. In order to form a neighbor relationship between two routers, the interfaces used to form the relationship must be in the same area. Generally an interface is only configured in a single area, however you can configure an interface to belong to multiple areas. In the second area, such an interface must be configured as a secondary interface. (A neighbor state simulation shows how neighbor state changes from Down to Full Adjacency progressively with exchanging Hello, DD, Request, Update, and Ack packets).