Question 1

Which of the following network types have a designated router and a backup designated router assigned? Broadcast Point-to-point NBMA NBMA point-to-point

Accepted Answer

No DR is assigned on any type of point-to-point link. No DR/BDR is assigned on the NBMA point-to-multipoint due to the hub/spoke topology. DR and BDR are elected on broadcast and non-broadcast multi-access networks. Frame Relay is a non-Broadcast Multi-Access (NBMA) network by default.

Question 2

Which of the following protocols support VLSM, summarization, and discontiguous networking? RIPv1 IGRP EIGRP OSPF BGP RIPv2

Accepted Answer

RIPv1 and IGRP are true distance-vector routing protocols and can't do much, really-except build and maintain routing tables and use a lot of bandwidth! RIPv2, EIGRP, and OSPF build and maintain routing tables, but they also provide classless routing, which allows for VLSM, summarization, and discontiguous networking.

Question 3

What is the administrative distance of OSPF?

Accepted Answer

The administrative distance (AD) is a very important parameter in a routing protocol. The lower the AD, the more trusted the route. If you have IGRP and OSPF running, by default IGRP routes would be placed in the routing table because IGRP has a lower AD of 100. OSPF has an AD of 110. RIPv1 and RIPv2 both have an AD of 120, and EIGRP is the lowest, at 90.

Question 4

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

Accepted Answer

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.

Question 5

Your company is running IGRP using an AS of 10. You want to configure EIGRP on the network but want to migrate slowly to EIGRP and don't want to configure redistribution. What command would allow you to migrate over time to EIGRP without configuring…

Accepted Answer

If you enable EIGRP on a router with the same autonomous system (AS) number, EIGRP will automatically redistribute IGRP into EIGRP. You will see the IGRP injected routes as external (EX) routes with an EIGRP AD of 170. This is a nice feature that lets you migrate slowly to EIGRP with no extra configuration.

Question 6

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

Accepted Answer

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.

Question 7

A network administrator needs to configure a router with a distance-vector protocol that allows classless routing. Which of the following satisfies those requirements?

Accepted Answer

In this question, we're calling EIGRP just plain old distance vector. EIGRP is an "advanced" distance-vector routing protocol, sometimes called a hybrid routing protocol because it uses the characteristics of both distance-vector and link-state routing protocols.

Question 8

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?

Accepted Answer

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.

Question 9

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, th…

Accepted Answer

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.

Question 10

Which of the following describe the process identifier that is used to run OSPF on a router? It is locally significant. It is globally significant. It is needed to identify a unique instance of an OSPF database. It is an optional parameter required …

Accepted Answer

The Process ID for OSPF on a router is only locally significant and you can use the same number on each router, or each router can have a different number-it just doesn't matter. The numbers you can use are from 1 to 65,535. Don't get this confused with area numbers, which can be from 0 to 4.2 billion.

Question 11

Which type of OSPF network will elect a backup designated router? Broadcast multi-access Non-broadcast multi-access Point-to-point Broadcast multipoint

Accepted Answer

DR and BDR are elected on broadcast and non-broadcast multi-access networks. Frame Relay is a non-broadcast multi-access (NBMA) network by default. No DR is assigned on any type of point-to-point link. No DR/BDR is assigned on the NBMA point-to-multipoint due to the hub/spoke topology.

Question 12

Where are EIGRP successor routes stored?

Accepted Answer

Successor routes are going to be in the routing table since they are the best path to a remote network. However, the topology table has a link to each and every network, so the best answer is topology table and routing table. Any secondary route to a remote network is considered a feasible successor, and those routes are only found in the topology table and used as backup routes in case of primary route failure.

Question 13

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

Accepted Answer

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.

Question 14

Which is true regarding EIGRP successor routes? A successor route is used by EIGRP to forward traffic to a destination. Successor routes are saved in the topology table to be used if the primary route fails. Successor routes are flagged as "active" …

Accepted Answer

Successor routes are the routes picked from the topology table as the best route to a remote network, so these are the routes that IP uses in the routing table to forward traffic to a remote destination. The topology table contains any route that is not as good as the successor route and is considered a feasible successor, or backup route. Remember that all routes are in the topology table, even successor routes.

Question 15

With which network type will OSPF establish router adjacencies but not perform the DR/BDR election process?

Accepted Answer

No DR is assigned on any type of point-to-point link. No DR/BDR is assigned on the NBMA point-to-multipoint due to the hub/spoke topology. DR and BDR are elected on broadcast and non-broadcast multi-access networks. Frame Relay is a non-broadcast multi-access (NBMA) network by default.

Question 16

You need the IP address of the devices with which the router has established an adjacency. Also, the retransmit interval and the queue counts for the adjacent routers need to be checked. What command will display the required information?

Accepted Answer

The show ip eigrp neighbors command allows you to check the IP addresses as well as the retransmit interval and queue counts for the neighbors that have established an adjacency.

Question 17

You get a call from a network administrator who tells you that he typed the following into his router: Router(config)#router ospf 1
Router(config-router)#network 10.0.0.0 255.0.0.0 area 0 He tells you he still can't see any routes in the routing tab…

Accepted Answer

The administrator typed in the wrong wildcard mask configuration. The wildcard should have been 0.0.0.255.

Question 18

Which command will display all the EIGRP feasible successor routes known to a router?

Accepted Answer

Any secondary route to a remote network is considered a feasible successor, and those routes are only found in the topology table and used as backup routes in case of primary route failure. You can see the topology table with the show ip eigrp topology command.

EIGRP and OSPF Questions