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1 Which address provides an example of an IPv6 link -local address?

FE80::1324:ABCD
2001:2345:AB12:1935::FEFF
2001:1234:0000:9CA::0876/64
1234:ABCD:5678:EF00:9234:AA22:5527:FC35

Observable Description Max Value
1 correctness of response 2 points for Option 1
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
7.3.2 IPv6 Addressing

2 While configuring a router using RIPng and dual -stack technology with IPv4 and
IPv6, the administrator receives an error message when inputting IPv4 routes. What
could cause the error message?

IPv4 is not compatible with RIPng
RIPng is incompatible with dual-stack technology.
The router interfaces have been configured with incorrect addresses.
When IPv4 and IPv6 are configured on the same interface, all IPv4 addresses are shut
down in favor of the newer technology.

Observable Description Max Value
1 correctness of response 2 points for Option 1
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
7.3.6 Routing Considerations with IPv6

3 Which statement is true about an interface that is configured with the IPv6 address
command?

IPv6 traffic-forwarding is enabled on the interface.
A link-local IPv6 address is automatically configured on the interface.
A global unicast IPv6 address is dynamically configured the interface.
Any IPv4 addresses that are assigned to the interface are replaced with an IPv6
address.

Observable Description Max Value
1 correctness of response 2 points for Option 2
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
7.3.7 Configuring IPv6 Addresses

4 What will be the result of adding the command ip dhcp excluded -address 172.16.4.1
172.16.4.5 to the configuration of a local router that has been configured as a DHCP
server?

Traffic that is destined for 172.16.4.1 and 172.16.4.5 will be dropped by the router.
Traffic will not be routed from clients with addresses between 172.16.4.1 and
172.16.4.5.
The DHCP server function of the router will not issue the addresses between
172.16.4.1 and 172.16.4.5.
The router will ignore all traffic that comes from the DHCP servers with addresses
172.16.4.1 and 172.16.4.5.

Observable Description Max Value
1 correctness of response 2 points for Option 3
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
7.1.4 Configuring a DHCP Server

5

Refer to the exhibit. A host that is connected to Fa0/0 is unable to acquire an IP
address dynamically from the DHCP server. The output of the debug ip dhcp server
command shows "DHCPD: there is no address pool for 172.16.1.1". What is the
problem?

The default router for the 172Network pool is incorrect.
The 172.16.1.1 address is already configured on Fa0/0.
The pool of addresses for the 172Network pool is incorrect.
The ip helper-address command should be implemented on the Fa0/0 interface.

Observable Description Max Value
1 correctness of response 2 points for Option 3
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
7.1.8 Troubleshooting DHCP

6 What does an access control list determine when used with NAT on a Cisco router?

addresses that are to be translated
addresses that are assigned to a NAT pool
addresses that are allowed out of the router
addresses that are accessible from the inside network

Observable Description Max Value
1 correctness of response 2 points for Option 1
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
7.2.5 Configuring Dynamic NAT

7 A system administrator must provide Internet connectivity for ten hosts in a small
remote office. The ISP has assigned two public IP addresses to this remote office.
How can the system administrator configure the router to provide Internet access to
all ten users at the same time?

Configure static NAT.
Configure dynamic NAT.
Configure static NAT with overload.
Configure dynamic NAT with overload.
Observable Description Max Value
1 correctness of response 2 points for Option 4
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
7.2.6 Configuring NAT Overload

8 What three statements describe the roles of devices in a WAN? (Choose three.)

A CSU/DSU terminates a digital local loop.
A modem terminates a digital local loop.
A CSU/DSU terminates an analog local loop.
A modem terminates an analog local loop.
A router is commonly considered a DTE device.
A router is commonly considered a DCE device.

Observable Description Max Value
1 correctness of response Option 1, Option 4, and Option 5 are correct.
1 point for each correct option.
0 points if more options are selected than required. 3

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
1.2.2 WAN Physical Layer Concepts

9 At what physical location does the responsibility for a WAN connection change
from the service provider to the user?

DMZ
local loop
CSU/DSU
demarcation point

Observable Description Max Value
1 correctness of response 2 points for Option 4
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
2.1.3 Demarcation Point

10

Refer to the exhibit. Which statement is true about the WAN switch device?

It uses a multiport internetworking device to switch traffic such as Frame Relay, ATM
or X.25 over the WAN.
It provides internetworking and WAN access interface ports that are used to connect
to the service provider network.
It provides termination for the digital signal and ensures connection integrity
through error correction and line monitoring.
It converts the digital signals produced by a computer into voice frequencies that can
be transmitted over the analog lines of the public telephone network.

Observable Description Max Value
1 correctness of response 2 points for Option 1
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
1.2.2 WAN Physical Layer Concepts

11

Refer to the exhibit. A network administrator is using two routers to test a WAN
connection . What can be concluded based on the output of the show running -config
commands?

The WAN link is using PPP encapsulation.
The WAN link speed is faster than a T1 line.
The router R2 serves as the DCE for the WAN link.
The WAN link is configured with the Cisco default encapsulation protocol.

Observable Description Max Value
1 correctness of response 2 points for Option 4
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
2.1.5 HDLC Encapsulation

12 Which important piece of troubleshooting information can be disco vered about a
serial interface using the show controllers command?

queuing strategy
serial cable type
interface IP address
encapsulation method
Observable Description Max Value
1 correctness of response 2 points for Option 2
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
2.1.7 Troubleshooting a Serial Interface

13 Which combination of Layer 2 protocol and authentication should be used to
establish a link between a Cisco and a non-Cisco router without sending
authentication information in plain text?

HDLC with PAP
HDLC with CHAP
PPP with PAP
PPP with CHAP

Observable Description Max Value
1 correctness of response 2 points for Option 4
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
2.4.1 PPP Authentication Protocols
2.4.3 Challenge Handshake Authentication Protocol (CHAP)

14 Which three items are LCP options that can be configured for PPP? (Choose
three.)
CHAP
Stacker
IPCP
CDPCP
Multilink

Observable Description Max Value
1 correctness of response Option 1, Option 2, and Option 5 are correct.
1 point for each correct option.
0 points if more options are selected than required. 3

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
2.2.5 Establishing a Link with LCP

15 At what point in the PPP connection process does the authentication phase occur?

after NCP establishes Layer 3 parameters
before LCP begins the link establishment process
after the initial Configure-Request message from the link initiator
after the link initiator receives a Configure-Ack message from the responder

Observable Description Max Value
1 correctness of response 2 points for Option 4
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
2.2.5 Establishing a Link with LCP
16

Refer to the exhibit. Why are the routers unable to establish a PPP session?

The usernames are misconfigured.
The IP addresses are on different subnets.
The clock rate is configured on the wrong end of the link.
The CHAP passwords must be different on the two routers.
Interface serial 0/0/0 on Router1 must connect to interface serial 0/0/1 on Router2.

Observable Description Max Value
1 correctness of response 2 points for Option 1
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
2.4.5 Configuring PPP with Authentication

17

Refer to the exhibit. What would be the result of entering the exhibited configuration
on a Frame Relay router?

The local interface DLCI will be set to 102.
All traffic that is destined to 172.16.16.8 will be sent as broadcast.
Only broadcast traffic will be recieved on the Frame Relay interface.
Routing protocol multicast updates can be forwarded across the Frame Relay PVC.
Observable Description Max Value
1 correctness of response 2 points for Option 4
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
3.2.2 Configuring Static Frame Relay Maps

18

Refer to the exhibit. What is placed in the address field in the header of a frame that
will travel from the DC office of ABC Company to the Orlando office?

MAC address of the Orlando router
MAC address of the DC router
192.168.1.25
192.168.1.26
DLCI 100
DLCI 200

Observable Description Max Value
1 correctness of response 2 points for Option 6
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
3.1.3 Frame Relay Encapsulation

19 A company uses a PVC with a committed information rate (CIR) of 128 kb/s and a
committed burst information rate (CBIR) of 64 kb/s. The link is used to periodically
send updates at a rate of 144 kb/s. What will happen to the update traffic?

The traffic will be sent, but the company will be charged a penalty.
The traffic will be sent using the additional CBIR and will be guaranteed delivery.
The traffic will be dropped at the CO for exceeding the committed information rate.
The traffic will be sent, but the burst traffic will be marked for discard if congestion is
encountered.

Observable Description Max Value
1 correctness of response 2 points for Option 4
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
3.3.2 Paying for Frame Relay

20 Which two functions are provided by the Local Management Interface (LMI) that
is used in Frame Relay networks? (Choose two.)

flow control
error notification
congestion notification
the mapping of DLCIs to network addresses
the sending of keepalive packets to verify operation of the PVC

Observable Description Max Value
1 correctness of response Option 1 and Option 5 are correct.
1 point for each correct option.
0 points if more options are selected than required. 2
This item references content from the following areas:
CCNA Exploration: Accessing the WAN
3.1.5 Frame Relay Address Mapping

21

Refer to the exhibit. You are a network administrator who has been tasked with
completing the Frame Relay topology that interconnects two remote sites. How
should the point-to-point subinterfaces be configured on HQ to complete the
topology?

HQ(config-subif)#frame-relay interface-dlci 103 on Serial 0/0/0.1
HQ(config-subif)#frame-relay interface-dlci 203 on Serial 0/0/0.2
HQ(config-subif)#frame-relay interface-dlci 301 on Serial 0/0/0.1
HQ(config-subif)# frame-relay interface-dlci 302 on Serial 0/0/0.2
HQ(config-subif)#frame-relay map ip 172.16.1.1 103 broadcast on Serial 0/0/0.1
HQ(config-subif)#frame-relay map ip 172.16.2.2 203 broadcast on Serial 0/0/0.2
HQ(config-subif)#frame-relay map ip 172.16.1.1 301 broadcast on Serial 0/0/0.1
HQ(config-subif)#frame-relay map ip 172.16.2.2 302 broadcast on Serial 0/0/0.2

Observable Description Max Value
1 correctness of response 2 points for Option 2
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
3.4.1 Configuring Frame Relay Subinterfaces

22
Refer to the exhibit. Branch A has a Cisco router. Branch B has a non-Cisco router set
for IETF encapsulation. After the commands shown are entered, R2 and R3 fail to
establish the PVC. The R2 LMI is Cisco, and the R3 LMI is ANSI. The LMI is
successfully established at both locations. Why is the PVC failing?

The PVC to R3 must be point-to-point.
LMI types must match on each end of a PVC.
The ietf parameter is missing from the frame-relay map ip 10.10.10.3 203 command.
The PVCs at R2 use different encapsulation types. A single port can only support one
encapsulation type.

Observable Description Max Value
1 correctness of response 2 points for Option 3
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
3.1.5 Frame Relay Address Mapping

23

Refer to the exhibit. A technician is teaching a trainee to interpret the results of
various Frame Relay troubleshooting commands. What conclusion can be drawn
from the output that is shown?

Neighboring routers should use DLCI 177 to reach the Branch r outer.
DLCI 177 will be used to identify all broadcasts that are sent out the Branch router.
The Branch router has the address 192.168.3.1 configured for the S0/0/0 interface.
To reach 192.168.3.1, the Branch router will use the virtual circuit that is identified by
DLCI 177.
Observable Description Max Value
1 correctness of response 2 points for Option 4
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
3.1.5 Frame Relay Address Mapping

24

Refer to the exhibit. Which statement is true about the status of the Frame Relay
connection?

The Frame Relay connection is in the process of negotiation.
Only packets with control bit DE set are sent over the PVC. No data traffic traverses
the link.
Packets marked as FECN and BECN indicate that a congestion control mechanism is
enabled on the Frame Relay PVC.
The ³DLCI USAGE = LOCAL´ status indicates that the PVC link is not established
between the interface S0/0/0.1 and the Frame Relay switch.

Observable Description Max Value
1 correctness of response 2 points for Option 3
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
3.3.3 Frame Relay Flow Control
25 Which wireless solution can provide mobile users with non line -of-sight
broadband Internet access at speeds comparable to DSL or cable?

Wi-Fi
WiMAX
satellite
Metro Ethernet

Observable Description Max Value
1 correctness of response 2 points for Option 2
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
1.3.5 Internet Connection Options

26 What are two characteristics of DSL technology? (Choose two.)

Uploads typically offer larger transfer rates than downloads.
Service providers deploy DSL in the local loop of the telephone network.
DSL download rates are reduced by large volumes of POTS voice traffic.
Filters and splitters allow POTS and DSL traffic to shar e the same medium.
DSL is a shared medium that allows many users to share bandwidth available from
the DSLAM.

Observable Description Max Value
1 correctness of response Option 2 and Option 4 are correct.
1 point for each correct option.
0 points if more options are selected than required. 2
This item references content from the following areas:
CCNA Exploration: Accessing the WAN
6.2.3 DSL

27

Refer to the exhibit. A packet is being sent from Host A to Host B through the VPN
tunnel between R1 and R3. When the packet first arrives at R3, what are the source
and destination IP addresses of the packet?

Source 192.168.1.2 - Destination 192.168.4.2
Source 192.168.3.1 - Destination 192.168.3.2
Source 192.168.2.1 - Destination 192.168.3.2
Source 192.168.3.1 - Destination 192.168.4.2

Observable Description Max Value
1 correctness of response 2 points for Option 3
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
6.3.5 VPN Tunneling

28 What is a major characteristic of a worm?

malicious software that copies itself into other executable programs
tricks users into running the infected software
a set of computer instructions that lies dormant until triggered by a specific event
exploits vulnerabilities with the intent of propagating itself across a network
Observable Description Max Value
1 correctness of response 2 points for Option 4
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
4.1.3 Types of Network Attacks

29 What is the function of an IDS?

to report the attack after it happens
to stop the attack prior to its completion
to quarantine the virus or worm so as not to infect an y other host
to reconfigure the security policy of a firewall to prevent another attack

Observable Description Max Value
1 correctness of response 2 points for Option 1
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
4.1.4 General Mitigation Techniques

30 When configuring remote access to a router, what is the significance of the no
password command on a VTY line?

Logins are prevented on that line.
No password is required to log in to that line.
The remote user is not allowed to change the password for that line.
The remote user is prompted to change the line password after connecting to the
router.

Observable Description Max Value
1 correctness of response 2 points for Option 1
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
4.2.4 Securing Remote Administrative Access to Routers

31 What will be the result of the enable secret command when added at the global
configuration mode on the router?

It will use MD5 encryption to protect the privileged EXEC level access.
It will use type 7 encryption and will encrypt only the privileged EXEC level
passwords.
It will use type 7 encryption to prevent all passwords that are displayed on the screen
from being readable.
It will use MD5 encryption to protect the passwords that are only used in the PAP and
CHAP authentication process.

Observable Description Max Value
1 correctness of response 2 points for Option 1
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
4.2.3 Manage Router Security

32

Refer to the exhibit. A network administrator is trying to backup the IOS software on
R1 to the TFTP server. He receives the error message that is shown in the exhibit, and
cannot ping the TFTP server from R1. What action can help to isolate this problem?

Check that R1 has a route to the 10.10.10.0 network.
Verify that the TFTP server software supports binary file transfers.
Make sure that the TFTP server has 192.168.1.1 as its default gateway.
Ensure that the laptop has an IP address in the 192.168.1.0/24 network.

Observable Description Max Value
1 correctness of response 2 points for Option 1
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
4.5.4 Backing up and Upgrading Software Image

33 A network technician accidentally deleted the IOS image from flash and rebooted
the router. Which two options can be used to restore the IOS image? (Choose two.)

Perform a system restore through SDM.
Download the image from a TFTP server through a network connection.
Download the image from a TFTP server through a console connection.
Establish an FTP session through an SSH connection for the image download.
Use the Xmodem protocol to download the image through a console connection.
Observable Description Max Value
1 correctness of response Option 2 and Option 5 are correct.
1 point for each correct option.
0 points if more options are selected than required. 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
4.5.5 Recovering Software Images

34

Refer to the exhibit. The network administrator creates a standard access control list
to prohibit traffic from the 192.168.1.0/24 network from reaching the 192.168.2.0/24
network while still permitting Internet access for all networks. On which router
interface and in which direction should it be applied?

interface fa0/0/0, inbound
interface fa0/0/0, outbound
interface fa0/0/1, inbound
interface fa0/0/1, outbound

Observable Description Max Value
1 correctness of response 2 points for Option 4
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
5.1.8 Where to Place ACLs
35 What effect would the Router1(config-ext-nacl)# permit tcp 172.16.4.0 0.0.0.255
any eq www command have when implemented inbound on the f0/0 interface?

All TCP traffic is permitted, and all other traffic is denied.
The command is rejected by the router because it is incomplete.
All traffic from 172.16.4.0/24 is permitted anywhere on any port.
Traffic originating from 172.16.4.0/24 is permitted to all TCP port 80 destinations.

Observable Description Max Value
1 correctness of response 2 points for Option 4
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
5.3.4 Creating Named Extended ACLs

36

Refer to the exhibit. Which two statements correctly describe how Router1 processes
an FTP request that enters interface S0/0/0 and is destined for an FTP server at IP
address 192.168.1.5? (Choose two.)

The packet does not match an access list condition.
The router matches the incoming packet to the statement that is created from the
access-list 201 permit ip any any command.
The router matches the incoming packet to the statement that is created from the
access-list 101 permit ip any 192.168.1.0 0.0.0.255 command.
The router matches the incoming packet to the statement that is created from the
access-list 201 deny icmp 192.168.1.0 0.0.0.255 any command.
The packet is allowed into Router1.
Observable Description Max Value
1 correctness of response Option 3 and Option 5 are correct.
1 point for each correct option.
0 points if more options are selected than required. 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
5.1.4 ACL Operation

37

Refer to the exhibit. An ACL numbered 101 already exists on this router. What
happens if the network administrator issues the commands that are shown in the
exhibit?

The new ACL overwrites the existing ACL.
The network administrator will receive an error message.
The existing ACL is modified to include the new commands.
A second ACL that is numbered 101 is created and contains only the new commands.

Observable Description Max Value
1 correctness of response 2 points for Option 3
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
5.2.5 Editing Numbered ACLs

38
Refer to the exhibit. What is the effect of the extended ACL when applied inbound on
the S0/0/0 interface on R2?

All IP traffic will be permitted during the specified days and time range.
Both IP and Telnet traffic will be permitted during the specified days and time range.
Only Telnet traffic destined for 172.16.10.0/24 will be permitted during the specified
days and time range.
Telnet traffic will be permitted only during the specified days and time range. All
other network traffic will be permitted any time.

Observable Description Max Value
1 correctness of response 2 points for Option 4
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
5.4.4 Time-based ACLs

39 Which wildcard mask would specify all IP addresses from 192.168.8.0 through
192.168.15.255?

0.0.0.7
0.0.7.255
0.0.8.255
0.0.15.255
0.0.255.255

Observable Description Max Value
1 correctness of response 2 points for Option 2
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
5.2.3 ACL Wildcard Masking

40

Refer to the exhibit. The SSH connections between the remote user and the server are
failing. The correct configuration of NAT has been verified. What is the most like ly
cause of the problem?

SSH is unable to pass through NAT.
There are incorrect access control list entries.
The access list has the incorrect port number for SSH.
The ip helper command is required on S0/0/0 to allow inbound connections.

Observable Description Max Value
1 correctness of response 2 points for Option 2
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
8.4.5 Transport Layer Troubleshooting

41 A network administrator added two switches and a new VLAN over the past
weekend. How can the administrator determine if the additions and changes
improved performance and availability on the company intranet?

Perform a baseline test and compare the current values to values that were obtained
in previous weeks.
Interview departmental secretaries and determine if they think load time for web
pages is improved.
Compare the hit counts on the company web server for the current week to the values
that were recorded from previous weeks.
Performance on the intranet can be determined by monitoring load times of company
web pages from remote sites.

Observable Description Max Value
1 correctness of response 2 points for Option 1
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
8.1.3 Why is Establishing a Network Baseline Important?

42 A company has its headquarters office in Dallas and five branch offices located in
New York, Chicago, Los Angeles, Seattle, and Atlanta. WAN links are used for
communications among offices in six sites. In planning the WAN links, the network
designer is given two requirements: (1) minimize cost and (2) provide a certain level
of WAN link reliability with redundant links. Which topology should the network
designer recommend?

star
full mesh
hierarchical
partial mesh

Observable Description Max Value
1 correctness of response 2 points for Option 4
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
8.3.4 WAN Topology Considerations

43

Refer to the exhibit. Router1 and Router2 each support separate areas of a data
center, and are connected via a crossover cable. Resources attached to Router1 are
unable to connect to resources attached to Router2. What is the likely cause?

The crossover cable is faulty.
The IP addressing is incorrect.
There is a Layer 2 problem with the router connection.
The upper layers are experiencing an unspecified problem.
One or both of the Ethernet interfaces are not working correctly.

Observable Description Max Value
1 correctness of response 2 points for Option 2
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
8.4.4 Network Layer Troubleshooting

44 An administrator is unable to receive e-mail. While troubleshooting the problem,
the administrator is able to ping the local mail server IP address successfully from a
remote network and can successfully resolve the mail server name to an IP address
via the use of the nslookup command. At what layer of the OSI model is the problem
most likely to be found?

application
transport
network
data link

Observable Description Max Value
1 correctness of response 2 points for Option 1
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
8.4.6 Application Layer Troubleshooting

45

Refer to the exhibit. A network technician has been called in to resolve a problem
with this network segment. The symptoms include a loss of connectivity throughout
the network segment, high link utilization, and syslog messages that indicate constant
MAC address relearning. What is the likely cause of these symptoms?

cable fault
faulty NIC card
IP addressing error
spanning tree problem
NAT configuration error

Observable Description Max Value
1 correctness of response 2 points for Option 4
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
8.4.3 Data Link Layer Troubleshooting

46

Refer to the exhibit. The corporate network that is shown has been assigned network
172.16.128.0/19 for use at branch office LANs. VLSM is not being used. Which subnet
mask will allow the most efficient utilization of IP addresses?

/21
/22
/23
/24
/25
/26

Observable Description Max Value
1 correctness of response 2 points for Option 1
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
8.5.3 Troubleshooting Enterprise Networks 3

47

Refer to the exhibit. Which VLAN will carry untagged traffic on FastEthernet 0/1?
VLAN 1
VLAN 2
VLAN 11
VLAN 12
VLAN 30
VLAN 999

Observable Description Max Value
1 correctness of response 2 points for Option 2
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
8.5.3 Troubleshooting Enterprise Networks 3

48

Refer to the exhibit. In the partial router configuration that is shown, what is the
purpose of access list BLOCK_XYZ?

to prevent source IP address spoofing by hosts on the Fa0/0 LAN
to block access by Fa0/0 LAN hosts to all network services beyond the router
to prevent users on the Fa0/0 LAN from opening Telnet sessions on the router
to secure Fa0/0 hosts by allowing only locally sourced traffic into the Fa0/0 LAN

Observable Description Max Value
1 correctness of response 2 points for Option 1
0 points for any other option 2
This item references content from the following areas:
CCNA Exploration: Accessing the WAN
5.2.6 Creating Standard Named ACLs

49

Refer to the exhibit. Routers R1 and R2 are both configured for single area OSPF.
Users who are connected to switch S1 are unable to access database applications that
run on servers that are connected to S2. The network engineer is working remotely
and only has the information that is shown in the ex hibit to direct initial
troubleshooting efforts. Based on the exhibit, which OSI layer is the most appropriate
to start with for a divide-and-conquer approach?

network layer
application layer
data-link layer
physical layer

Observable Description Max Value
1 correctness of response 2 points for Option 3
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
8.5.3 Troubleshooting Enterprise Networks 3

50

Refer to the exhibit. An administrator has added the exhibited commands to routers
A and B, but no routing updates are exchanged between the two routers. Based on the
information that is given, what is the likely cause of the problem?

Router A is advertising the wrong network.
The authentication key strings do not match.
The serial interfaces of routers A and B are not on the same network.
The authentication key numbers do not match the EIGRP process number for both
routers.

Observable Description Max Value
1 correctness of response 2 points for Option 2
0 points for any other option 2

This item references content from the following areas:
CCNA Exploration: Accessing the WAN
4.3.2 Securing Routing Protocols