Eigrp And Ospf

If routers in a single area are configured with the same priority value, what value does a router use for the OSPF Router ID in the absence of a loopback interface?

A:

The lowest IP address of any physical interface

B:

The highest IP address of any physical interface

C:

The lowest IP address of any logical interface

D:

The highest IP address of any logical interface

Answer: B

At the moment of OSPF process startup, the highest IP address on any active interface will be the Router ID (RID) of the router. If you have a loopback interface configured (logical interface), then that will override the interface IP address and become the RID of the router automatically.

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Which two of the following commands will place network 10.2.3.0/24 into area 0?

router eigrp 10
router ospf 10
network 10.0.0.0
network 10.2.3.0 0.0.0.255 area0
network 10.2.3.0 0.0.0.255 area 0

A:

1 and 4

B:

2, 4, and 5

C:

2 and 5

D:

3 and 4

Answer: C

To enable OSPF, you must first start OSPF using a Process ID. The number is irrelevant; just choose a number from 1 to 65,535 and you're good to go. After you start the OSPF process, you must configure any network that you want advertised via OSPF using wildcards and the area command. Statement (4) is wrong because there must be a space after the parameter area and before you list the area number.

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What are reasons for creating OSPF in a hierarchical design?

To decrease routing overhead
To speed up convergence
To confine network instability to single areas of the network
To make configuring OSPF easier

A:

1, 2 and 3

B:

3 only

C:

3 and 4

D:

2, 3 nd 4

Answer: A

OSPF is created in a hierarchical design, not a flat design like RIP. This decreases routing overhead, speeds up convergence, and confines network instability to a single area of the network.

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Which of the following are true regarding OSPF areas?

You must have separate loopback interfaces configured in each area.
The numbers you can assign an area go up to 65,535.
The backbone area is also called area 0.
If your design is hierarchical, then you don't need multiple areas.
All areas must connect to area 0.

A:

1 only

B:

1 and 2 only

C:

3 and 4 only

D:

3, 4 and 5

Answer: D

Loopback interfaces are created on a router, and the highest IP address on a loopback (logical) interface becomes the RID of the router but has nothing to do with areas and is optional, so (1) is wrong. The numbers you can create an area with are from 0 to 4,294,967,295 option (2) is wrong. The backbone area is called area 0, so option (3) is correct. All areas must connect to area 0, so option (5) is correct. If you have only one area, it must be called area 0. This leaves option (4), which must be correct; it doesn't make much sense, but it is the best answer.

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Which EIGRP information is held in RAM and maintained through the use of Hello and update packets?

Neighbor table
STP table
Topology table
DUAL table

A:

2 only

B:

4 only

C:

1 and 3

D:

All of the above

Answer: C

EIGRP holds three tables in RAM: neighbor, topology, and routing. The neighbor and topology tables are built and maintained with the use of Hello packets.

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Questions for: Eigrp And Ospf