Testking_640-802_V13

Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,

r - Reply status

P 172.16.90.0 255.255.255.0, 2 successors, FD is 0 via 172.16.80.28 (46251776/46226176), Ethernet0 via 172.16.81.28 (46251776/46226176), Ethernet1 via 172.16.80.31 (46277376/46251776), Serial0

P 172.16.81.0 255.255.255.0, 1 successors, FD is 307200 via Connected, Ethernet1

via 172.16.81.28 (307200/281600), Ethernet1 via 172.16.80.28 (307200/281600), Ethernet0 via 172.16.80.31 (332800/307200), Serial0

Since in our example, the networks listed are connected are 192.168.2.0 and 192.168.10.0, this command must have been issued on router TestKing1.

QUESTION NO: 18

The TestKing network topology is displayed below:

Exhibit, TestKing1 configuration

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Based on the output of the TestKing1#show ip route command shown above and the information displayed in the network topology exhibit, which of the following is a potential routing problem?

A.The use of summarization for discontiguous networks

B.the use of CIDR with a routing protocol that does not support it

C.the use of VLSM with a routing protocol that does not support it

D.The use of the no auto-summary command with a protocol that does not support summarization

E.the use of the ip route 0.0.0.0 0.0.0.0 command with a routing protocol that does not support it

Answer: A Explanation:

By default, EIGRP will automatically summarize networks at their network boundary, which can cause problems with dis-contiguous IP networks. Since the IP routing table does indeed show a summary route to null 0, the default behavior of EIGRP was not modified. In this network, it would be best to disable the automatic summarization feature of EIGRP.

QUESTION NO: 19

The TestKing WAN is using EIGRP. Which two of the following are valid characteristics of this routing protocol? (Select two answer choices)

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A.Has a maximum hop count of 25

B.Can differentiate between internal and external routes

C.Uses a 32-bit metric

D.Can maintain only one routing table

E.Need all networks to use the same subnet mask

F.Supports only one routed protocol

Answer: B, C

Explanation:

By default, the EIGRP composite metric is a 32-bit quantity that is a sum of the segment delays and the lowest segment bandwidth.

Enhanced IGRP supports internal and external routes. Internal routes originate within an Enhanced IGRP AS. Therefore, a directly attached network that is configured to run Enhanced IGRP is considered an internal route and is propagated with this information throughout the Enhanced IGRP AS. External routes are learned by another routing protocol or reside in the routing table as static routes. These routes are tagged individually with theidentity of their origin.

Incorrect Answers:

A. This choice is wrong since it does not use hop count but a metrics that includes: bandwidth*, delay*, load, reliability, and MTU size. (* used by default).

D.This choice is wrong since we know that it keeps a three tables (neighbor table, topology table, and route table) and if you want to be a nit pick and say it still only supports one route table, then if you configure IP and IPX on the router, you will have two route tables one for each protocol.

E.This choice is wrong since we know that EIGRP supports VLSM.

F.This choice is wrong since we know it supports IP, IPX and Appletalk.

QUESTION NO: 20

Router TK1 is running EIGRP. In EIGRP; what is a feasible successor (FS) and where is it stored in this router?

A.A FS is a primary route, stored in the routing table

B.A FS is a backup route, stored in the routing table

C.A FS is a backup route, stored in the topology table

D.A FS is a primary route, stored in the topology table

E.None of the above

Answer: C

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Explanation:

The following are some terms relating to EIGRP:

1.Feasible Distance: The lowest calculated metric to each destination

2.Feasibility Condition: A condition that is met if a neighbor's advertised distance to a destination is lower that the router's Feasible Distance to that same destination.

3.Successor: The neighbor that has been selected as the next hop for a given destination based on the Feasibility Condition.

Reference: Jeff Doyle, Routing TCP/IP, Volume I, Chapter 8: Enhanced Interior Gateway Routing Protocol (EIGRP), p.336-337, Cisco Press, (ISBN 1-57870-041-8)

Additional info:

The Feasible Condition is met when the receiving router has a Feasible Distance (FD) to a particular network and it receives an update from a neighbor with a lower advertised or Reported Distance (RD) to that network. The neighbor then becomes a Feasible Successor (FS) for that route because it is one hop closer to the destination network. There may be a number of Feasible Successors in a meshed network environment.

The RD for a neighbor to reach a particular network must always be less than the FD for the local router to reach that same network. In this way EIGRP avoids routing loops. This is why routes that have RD larger than the FD are not entered into the Topology table. Reference: Ravi Malhotra, IP Routing, Chapter 4: Enhanced Interior Gateway Routing Protocol (EIGRP), O'Reilly Press, January 2002 (ISBN 0-596-00275-0)

QUESTION NO: 21

Router TK1 is running EIGRP. In what location are EIGRP successor routes stored in this router?

A.In the routing table only.

B.In the neighbor table only.

C.In the topology table only.

D.In the routing table and neighbor table.

E.In the routing table and topology table.

F.In the topology table and neighbor table.

G.None of the above

Answer: E

Explanation:

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A destination entry is moved from the topology table to the routing table when there is a feasible successor. All minimum cost paths to the destination form a set. From this set, the neighbors that have an advertised metric less than the current routing table metric are considered feasible successors.

Feasible successors are viewed by a router as neighbors that are downstream with respect to the destination. These neighbors and the associated metrics are placed in the forwarding table. Successor information is needed by the routing table and by the topology table, so they are stored in both.

QUESTION NO: 22

Router TK1 has EIGRP configured as the only routing protocol. How does EIGRP respond if there is no feasible successor route to a destination network and the successor route fails?

A.It immediately sends its entire routing table to its neighbors.

B.EIGRP sends a Hello packet to the DR to inform it of the route failure.

C.It automatically forwards traffic to a fallback default route until a successor route is found.

D.It sends queries out to neighbors until a new successor route is found.

E.It places the route in holddown until LSA updates inform it of a new route to the network.

F.None of the above

Answer: D Explanation:

EIGRP will send queries for successor if it can't find a path to destination (if no feasible successors already exist).

QUESTION NO: 23

EIGRP is configured on router TK1. What does this router do if it has no EIGRP feasible successor route to a destination network and the successor route to that destination network is inactive status?

A.It routes all traffic that is addresses to the destination network to the interface indicates in the routing table.

B.It sends a copy of its neighbor table to all adjacent routers.

C.

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It sends a multicast query packet to all adjacent neighbors requesting available routing paths to the destination network.

D.It broadcasts Hello packets to all routers in the network to re-establish neighbor adjacencies.

E.None of the above

Answer: C Explanation:

When the primary route is not available, EIGRP immediately uses the feasible successor as the backup route. This shortens convergence time. Now, if the primary route is gone and no feasible successor is available, the route is in active state. The only way for EIGRP to converge quickly is to query its neighbors about the unavailable route. If the neighbor doesn't know the status of the route, the neighbor asks its neighbors, and so on, until the edge of the network is reached. The query stops if one of the following occurs: All queries are answered from all the neighbors.

The end of network is reached.

The lost route is unknown to the neighbors.

Reference:

http://www.ciscopress.com/articles/article.asp?p=27839&rl=1

Section 14: Verify network connectivity (including: using ping, traceroute, and telnet or SSH) (5 questions)

QUESTION NO: 1

As a network administrator, you use a telnet program often. What are two characteristics of Telnet? (Choose two.)

A.It is no longer supported on Cisco network devices

B.It is more secure than SSH

C.It requires that the destination device be configured to support Telnet connections

D.It requires an enterprise license in order to be implemented

E.It sends data in clear and text format

Answer: C, E

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QUESTION NO: 2

Which of the following IOS commands could you use to troubleshoot a router connectivity problem on an IP network? (Select all valid answers)

A.show ip route

B.ipconfig

C.tracert

D.show interfaces

E.traceroute

F.ping

G.All of the above

Answer: A, D, E, F

Explanation:

A. The show ip route command displays the IP route table.

D.The show interfaces EXEC command to display statistics for all interfaces configured on the router or access server.

E.Traceroute is a valid router command, used to trace the path to a destination, and provide the latency associated with each hop.

F.The ping command tests connectivity to a remote node.

Incorrect Answers:

B, C. These are commands used on PC hosts. They are invalid router commands.

QUESTION NO: 3

What IOS command verifies connectivity between two hosts on the TestKing network by sending and receiving ICMP echo messages?

A.ping

B.tracert

C.netstat

D.show cdp neighbors detail

E.show ip route

F.traceroute

G.ipconfig

Answer: A

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Explanation:

Packet Internet Groper (PING) uses ICMP echo requests and replies to verify network connectivity. It is most commonly used to verify connectivity to another device and to monitor the operational status of a device.

QUESTION NO: 4

Part of the TestKing network is shown below:

In this network segment, host TestKingA is trying to communicate with Host TestKingB. The e0 interface on Router TestKing3 is down. Which of the following are true? (Choose two.)

A.Router TestKing3 will send a Source Quench message type.

B.Router TestKing3 will use ICMP to inform Host TestKingA, Router TestKing1, and Router TestKing2 that Host TestKingB cannot be reached.

C.Router TestKing3 will send a Router Selection message type.

D.Router TestKing3 will send a Destination Unreachable message type.

E.Router TestKing3 will use ICMP to inform Router TestKing2 that Host TestKingB cannot be reached.

F.Router TestKing3 will use ICMP to inform Host TestKingA that Host TestKingB cannot be reached.

Answer: D, F

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QUESTION NO: 5

What kind of message does a PING send out to test connectivity?

A.ICMP echo request

B.Information interrupt request

C.Timestamp reply

D.Source quench

E.None of the above

Answer: A Explanation:

The ping command sends an ICMP echo request packet to the stated destination address. The TCP/IP software at the destination then replies to the ping echo request packet with a similar packet, called the ICMP echo reply.

Reference: CCNA Self-Study CCNA ICND exam certification Guide (Cisco Press, ISBN 1-58720-083-X) Page 146

Section 15: Troubleshoot routing issues (5 questions)

QUESTION NO: 1

The topology table for the TestKing EIGRP network is shown below from router TestKing3:

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Based on the information shown above, how many broadcast domains exist in the TestKing EIGRP topology?

A.Six

B.One

C.Three

D.Two

E.Five

F.Four

G.None of the above

Answer: C

QUESTION NO: 2

The following output was shown on router TestKing4:

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