When are virtual links used in OSPF?

When are virtual links used in OSPF?
A . When two areas need to communicate and there is no area 0.
B . When an area needs to traverse another area to reach area 0.
C . When two areas are connected to area 0, but there is no direct path between them.
D . When an area needs to connect directly to another area without using area 0.

Answer: B

In the topology shown, router R1 is an ASBR configured to export external routes to OSPF.Which of the following statements regarding the OSPF LSAs in the network is true?

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In the topology shown, router R1 is an ASBR configured to export external routes to OSPF.Which of the following statements regarding the OSPF LSAs in the network is true?
A . Router R1 generates a type 5 LSA that is flooded through all OSPF areas.
B . Router R1 generates a type 7 LSA that is flooded through all OSPF areas.
C . Router R1 generates a type 5 LSA that is flooded through area 1.Router R2 generates a type 7 LSA that is flooded through areas 0 and 2.
D . Router R1 generates a type 7 LSA that is flooded through area 1.Router R3 generates a type 5 LSA that is flooded through areas 0 and 2.

Answer: D

Which of the following statements regarding OSPF routing updates on a point-to-point link is true?

Which of the following statements regarding OSPF routing updates on a point-to-point link is true?
A . On a point-to-point link, there is no need for a DR and BDR election; all routing updates are sent to 224.0.0.5.
B . On a point-to-point link, a DR and BDR are elected.The DR sends link-state advertisements describing the network.
C . On a point-to-point link, a DR and BDR are elected.To ensure resiliency, both the DR and BDR send link-state advertisements describing the network.
D . On a point-to-point link, there is no need for a DR and BDR election.All routing updates are sent to the unicast address of the neighbor’s interface.

Answer: A

Routers R1 „ R2, and R3 are running a classful routing protocol between them.Assuming that router R1 advertises all directly connected networks, how will these networks be represented in router R3’s routing table?

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Routers R1 „ R2, and R3 are running a classful routing protocol between them.Assuming that router R1 advertises all directly connected networks, how will these networks be represented in router R3’s routing table?

A . Router R3’s routing table can only contain one of the routes, which will result in route flapping.
B . Router R3’s routing table will have one entry for 10.1.1.0/24 and one entry for 10.1.2.0/24.
C . The networks will be represented with one entry of 10.0.0.0/8 in router R3’s routing table.
D . The networks will be represented with one entry of 10.0.0.0/24 in router R3’s route table.

Answer: C

Which of the following best describes the type of packets used by OSPF routers to exchange updates on a point-to-point link?

Which of the following best describes the type of packets used by OSPF routers to exchange updates on a point-to-point link?
A . IP packets sent to an IP multicast address.
B . TCP packets sent to an IP multicast address.
C . IP packets sent to an IP unicast address.
D . UDP packets sent to an IP multicast address.

Answer: A