QUESTION 51
What two things will a router do when running a distance vector routing protocol? (Choose two.)

A.    Send periodic updates regardless of topology changes.
B.    Send entire routing table to all routers in the routing domain.
C.    Use the shortest-path algorithm to the determine best path.
D.    Update the routing table based on updates from their neighbors.
E.    Maintain the topology of the entire network in its database.

Answer: AD
Explanation:
Distance means how far and Vector means in which direction. Distance Vector routing protocols pass periodic copies of routing table to neighbor routers and accumulate distance vectors. In distance vector routing protocols, routers discover the best path to destination from each neighbor. The routing updates proceed step by step from router to router.

QUESTION 52
Which command is used to display the collection of OSPF link states?

A.    show ip ospf link-state
B.    show ip ospf lsa database
C.    show ip ospf neighbors
D.    show ip ospf database

Answer: D
Explanation:
The “show ip ospf database” command displays the link states. Here is an example:
Here is the lsa database on R2.
R2#show ip ospf database
OSPF Router with ID (2.2.2.2) (Process ID 1)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count2.2.2.2 2.2.2.2 793 0x80000003 0x004F85 210.4.4.4 10.4.4.4 776 0x80000004 0x005643 1111.111.111.111 111.111.111.111 755 0x80000005 0x0059CA 2133.133.133.133 133.133.133.133 775 0x80000005 0x00B5B1 2 Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum10.1.1.1 111.111.111.111 794 0x80000001 0x001E8B10.2.2.3 133.133.133.133 812 0x80000001 0x004BA910.4.4.1 111.111.111.111 755 0x80000001 0x007F1610.4.4.3 133.133.133.133 775 0x80000001 0x00C31F

QUESTION 53
If IP routing is enabled, which two commands set the gateway of last resort to the default gateway? (Choose two.)

A.    ip default-gateway 0.0.0.0
B.    ip route 172.16.2.1 0.0.0.0 0.0.0.0
C.    ip default-network 0.0.0.0
D.    ip default-route 0.0.0.0 0.0.0.0 172.16.2.1
E.    ip route 0.0.0.0 0.0.0.0 172.16.2.1

Answer: CE
Explanation:
Both the “ip default-network” and “ip route 0.0.0.0 0.0.0.0 (next hop)” commands can be used to set the default gateway in a Cisco router.

QUESTION 54
Which parameter would you tune to affect the selection of a static route as a backup, when a dynamic protocol is also being used?

A.    hop count
B.    administrative distance
C.    link bandwidth
D.    link delay
E.    link cost

Answer: B
Explanation:
By default the administrative distance of a static route is 1, meaning it will be preferred over all dynamic routing protocols. If you want to have the dynamic routing protocol used and have the static route be used only as a backup, you need to increase the AD of the static route so that it is higher than the dynamic routing protocol.

QUESTION 55
Before installing a new, upgraded version of the IOS, what should be checked on the router, and which command should be used to gather this information? (Choose two.)

A.    the amount of available ROM
B.    the amount of available flash and RAM memory
C.    the version of the bootstrap software present on the router
D.    show version
E.    show processes
F.    show running-config

Answer: BD
Explanation:
When upgrading new version of the IOS we need to copy the IOS to the Flash so first we have to check if the Flash has enough memory or not. Also running the new IOS may require more RAM than the older one so we should check the available RAM too. We can check both with the “show version” command.

QUESTION 56
Which command reveals the last method used to powercycle a router?

A.    show reload
B.    show boot
C.    show running-config
D.    show version

Answer: D
Explanation:
The “show version” command can be used to show the last method to powercycle (reset) a router

QUESTION 57
Which command would you use on a Cisco router to verify the Layer 3 path to a host?

A.    tracert address
B.    traceroute address
C.    telnet address
D.    ssh address

Answer: B
Explanation:
In computing, traceroute is a computer network diagnostic tool for displaying the route (path) and
measuring transit delays of packets across an Internet Protocol (IP) network. The history of the route is recorded as the round-trip times of the packets received from each successive host (remote node) in the route (path); the sum of the mean times in each hop indicates the total time spent to establish the connection. Traceroute proceeds unless all (three) sent packets are lost more than twice, then the connection is lost and the route cannot be evaluated. Ping, on the other hand, only computes the final round-trip times from the destination point.

QUESTION 58
What information does a router running a link-state protocol use to build and maintain its topological database? (Choose two.)

A.    hello packets
B.    SAP messages sent by other routers
C.    LSAs from other routers
D.    beacons received on point-to-point links
E.    routing tables received from other link-state routers
F.    TTL packets from designated routers

Answer: AC
Explanation:
Neighbor discovery is the first step in getting a link state environment up and running. In keeping with the friendly neighbor terminology, a Hello protocol is used for this step. The protocol will define a Hello packet format and a procedure for exchanging the packets and processing the information the packets contain.
After the adjacencies are established, the routers may begin sending out LSAs. As the term flooding implies, the advertisements are sent to every neighbor. In turn, each received LSA is copied and forwarded to every neighbor except the one that sent the LSA.

QUESTION 59
Which statements describe the routing protocol OSPF? (Choose three.)

A.    It supports VLSM.
B.    It is used to route between autonomous systems.
C.    It confines network instability to one area of the network.
D.    It increases routing overhead on the network.
E.    It allows extensive control of routing updates.
F.    It is simpler to configure than RIP v2.

Answer: ACE
Explanation:
The OSPF protocol is based on link-state technology, which is a departure from the Bellman-Ford vector based algorithms used in traditional Internet routing protocols such as RIP. OSPF has introduced new concepts such as authentication of routing updates, Variable Length Subnet Masks (VLSM), route summarization, and so forth.
OSPF uses flooding to exchange link-state updates between routers. Any change in routing information is flooded to all routers in the network. Areas are introduced to put a boundary on the explosion of link-state updates. Flooding and calculation of the Dijkstra algorithm on a router is limited to changes within an area.

QUESTION 60
Refer to the exhibit. A network administrator configures a new router and enters the copy startup-config running-config command on the router. The network administrator powers down the router and sets it up at a remote location. When the router starts, it enters the system configuration dialog as shown. What is the cause of the problem?

A.    The network administrator failed to save the configuration.
B.    The configuration register is set to 0x2100.
C.    The boot system flash command is missing from the configuration.
D.    The configuration register is set to 0x2102.
E.    The router is configured with the boot system startup command.

Answer: A
Explanation:
The “System Configuration Dialog” appears only when no startup configuration file is found. The network administrator has made a mistake because the command “copy startup-config running- config” will copy the startup config (which is empty) over the running config (which is configured by the administrator). So everything configured was deleted. Note: We can tell the router to ignore the start-up configuration on the next reload by setting the register to 0?142. This will make the “System Configuration Dialog” appear at the next reload.

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