Download 1 In addition to assigning addresses from predefined pools, which

1 In addition to assigning addresses from predefined pools, which other services can a DHCP
server offer? (Choose three.)
DNS server addresses
domain names
global IP assignments
NAT translations
WINS server addresses
2
Given the accompanying graphic, which statement would be applied to the S0 interface when
configuring NAT on the Tampa router?
ip nat inside
ip nat outside
ip pat inside
ip pat outside
3
Given the accompanying graphic, which addresses could be assigned to traffic leaving S0 as a
result of the statement ip nat pool Tampa 179.9.8.96 179.9.8.111 netmask 255.255.255.240?
(Choose two.)
10.0.0.125
179.9.8.95
179.9.8.98
179.9.8.101
179.9.8.112
4
Given the accompanying graphic, which command would establish a group of 32 IP addresses
that could be used to hide inside addresses from the Internet?
ip nat pool Raleigh 10.0.0.32 10.0.0.63 netmask 255.255.255.224
ip nat pool Raleigh 10.0.0.32 10.0.0.63 netmask 255.255.255.240
ip nat pool Raleigh 171.11.10.32 171.11.10.63 netmask 255.255.255.224
ip nat pool Raleigh 171.11.10.32 171.11.10.63 netmask 255.255.255.240
5
What is the purpose of the command marked with an arrow shown in the partial configuration
output of a Cisco 806 broadband router?
defines which addresses are allowed out of the router
defines which addresses are allowed into the router
defines which addresses can be translated
defines which addresses are assigned to a NAT pool
6
Given the accompanying debug output from a Cisco router, what kind of address is 10.10.10.3
with the IP identification number of 29855?
inside local
inside global
outside local
outside global
7
The Raleigh router shown in the diagram is configured with PAT. Which of the following
must be changed if the private network is migrated to a 10.0.0.0 network? (Choose two.)
E0 interface address
S0 interface address
the access-list statement
the NAT outside interface
the NAT inside interface
8
Given the accompanying diagram, which commands are necessary to implement PAT on the
Raleigh router? (Choose four.)
access-list 10 permit 192.168.10.0 0.0.0.255
access-list 10 permit 171.11.0.0 0.0.255.255
ip nat inside source static 192.168.10.1 171.11.0.0
ip nat inside source list 10 interface S0 overload
ip nat outside
ip nat inside
9 Which of the following traffic types are supported by Cisco IOS NAT? (Choose two.)
Routing table updates
ICMP
FTP
BOOTP
SNMP
Cisco IOS NAT supports the following traffic types:
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ICMP
File Transfer Protocol (FTP), including PORT and PASV commands
NetBIOS over TCP/IP, datagram, name, and session services
RealNetworks' RealAudio
White Pines' CUSeeMe
Xing Technologies' StreamWorks
DNS "A" and "PTR" queries
H.323/Microsoft NetMeeting, IOS versions 12.0(1)/12.0(1)T and later
VDOnet's VDOLive, IOS versions 11.3(4)11.3(4)T and later
VXtreme's Web Theater, IOS versions 11.3(4)11.3(4)T and later
IP Multicast, IOS version 12.0(1)T with source address translation only
Cisco IOS NAT does not support the following traffic types:
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Routing table updates
DNS zone transfers
BOOTP
talk and ntalk protocols
Simple Network Management Protocol (SNMP)
10
Which of the following can be done to allow the users on the 10.0.0.0 network to
communicate with the Web Server shown in the graphic? (Choose two.)
Configure the Miami router to use NAT.
Configure the Web Server with a private address.
Configure the Miami router to use PAT.
Change the Internet link IP address of 128.56.0.0 to a private address.
Configure the Tampa router to use PAT.
11 What is true regarding the differences between NAT and PAT?
PAT uses the word "overload" at the end of the access-list statement to share a single
registered address.
Static NAT allows an unregistered address to map to multiple registered addresses.
Dynamic NAT allows hosts to receive the same global address each time external access is
required.
PAT uses unique source port numbers to distinguish between translations.
12 What is the purpose of the DHCPDECLINE message?
If the DHCP client received multiple DHCPOFFERs, it uses the DHCPDECLINE to refuse
the offers it does not use.
If the DHCP server sends an IP configuration update that the DHCP client does not need, it
uses the DHCPDECLINE to refuse the information.
The DHCP server uses the DHCPDECLINE message to refuse a DHCP client's request for IP
configuration information.
If the DHCP client detects that the address supplied by the DHCP server is in use on the
network, it uses the DHCPDECLINE to refuse the offer.
If the client detects that the address is already in use on the local segment it will send a
DHCPDECLINE message and the process starts again.
13 A network administrator needs to configure a router to offer DHCP services. Assuming the
router is operating with factory defaults and the IOS supports DHCP, what must be done to
start the DHCP service?
Use the global configuration command service dhcp.
Use the privileged command service dhcp start.
Use the start service dhcp command during the setup processes.
Do nothing. The DHCP service is enabled by default during start up.
14 Users are complaining that they cannot attach to network resources. A technician has
confirmed that clients are not properly receiving IP configuration information through the
DHCP process. The network administrator wants to watch the DHCP process while the
technician tries to release and renew addresses on the clients. Which command would the
network administrator use to monitor the process of address allocation?
show ip dhcp server statistics
show ip dhcp binding
debug ip dhcp server events
debug ip dhcp binding
15
Refer to the graphic. Which command would allow the router to forward DHCP broadcasts
from Host A to the DHCP server?
ip helper-address
dhcp helper-address
dhcp relay-agent
dhcp-relay
16 What is the default lease time for addresses assigned to clients through Easy IP?
twenty-four hours
forty-eight hours
one week
two weeks
17 A company was issued 207.48.12.8/29 as its registered address from its ISP. Which of the
following is a solution that will allow Internet access to 300 employees simultaneously?
VLSM to further subnet the registered address and create more IP addresses
normal subnetting on the Class C network and address the host
RFC 1918 and port address translation
this is an impossible scenario because there are not enough addresses
18 Which configuration parameters are provided by the dynamic allocation process of DHCP?
(Choose three.)
Gateway address
DNS server
DHCP Server
Subnet mask
Key server
ARP server
The focus of this section is the dynamic allocation mechanism. Some of the configuration parameters
available are listed in IETF RFC 1533:
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Subnet mask
Router
Domain Name
Domain Name Server(s)
WINS Server(s)
19 Which of the following are broadcasts sent by a client to a DHCP server? (Choose two.)
DHCPDISCOVER
DHCPRELEASE
DHCPACK
DHCPREQUEST
DHCPOFFER
20 Which configuration information might a DHCPOFFER include? (Choose three.)
IP address
DNS server address
DHCP binding
Lease time
DHCP database
If it can, the DHCP server offers the client IP configuration information in the form of a unicast
DHCPOFFER. The DHCPOFFER is a proposed configuration that may include IP address, DNS
server address, and lease time.
21 What is the default number of pings issued by a DHCP server to a pool address before
sending the DHCPOFFER to a client?
one
two
three
four
five
1 Which statement is true regarding WAN technologies?
Most WANS use only one technology throughout the infrastructure such as ISDN, Frame
Relay or ATM.
Data transfer speeds on the WAN are typically faster than the speeds on a LAN.
WANs operate at the lower three layers of the OSI model.
WANs are unable to support the transfer of voice or video traffic.
The data link layer protocols define how data is encapsulated for transmission to remote sites, and
the mechanisms for transferring the resulting frames. A variety of different technologies are used, such
as ISDN, Frame Relay or Asynchronous Transfer Mode (ATM).
2 Which statements are correct regarding ATM connections? (Choose two.)
uses only PVCs
is useful for video transfers
has data rates beyond 155 Mbps
cells have 32 byte payload and a 5 byte overhead
mandates single virtual circuits on a single leased line connection
3 On which of the following are most Layer 2 WAN encapsulations based?
IP
PPP
HDLC
SLIP
HSSI
CSU
WAN connection type uses a Layer 2 protocol to encapsulate traffic while it is crossing the WAN link.
To ensure that the correct encapsulation protocol is used, the Layer 2 encapsulation type used for
each router serial interface must be configured. The choice of encapsulation protocols depends on the
WAN technology and the equipment. Most framing is based on the HDLC standard.
4 A company requires a WAN connection that will carry 64 kbps and allow fast call setup
time. The connection does not need to carry video. What is the best choice for this company?
ATM
ISDN BRI
X.25
analog dialup
Basic Rate Interface (BRI) ISDN is intended for the home and small enterprise and provides two 64
kbps B channels and a 16 kbps D channel
5 Which of the following describes a packet-switched network using connection-oriented data
transfer? (Choose two.)
Each packet carries an identifier.
Each packet carries full addressing information.
Each switch in the route must evaluate the addressing information to determine where to send
the packet.
Each switch determines where to send the packet by examining tables in memory.
The addressing information is used to set switches along the route of data transfer to create a
continuous copper circuit.
The switches in a packet-switched network determine, from addressing information in each packet,
which link the packet must be sent on next. There are two approaches to this link determination,
connectionless or connection-oriented. Connectionless systems, such as the Internet, carry full
addressing information in each packet. Each switch must evaluate the address to determine where to
send the packet. Connection-oriented systems predetermine the route for a packet, and each packet
need only carry an identifier.
6 Which of the following connections will provide the equivalent of a T1/E1 connection and
is intended for large businesses?
BRI
PRI
DLCI
PSTN
POTS
In North America PRI corresponds to a T1 connection. The rate of international PRI
corresponds to an E1 connection.
7 Which of the following is commonly used as Data Terminal Equipment?
ISDN
modem
router
CSU/DSU
8 Which term describes the cabling that connects the customer site to the nearest exchange of
the WAN service provider?
CPE
CO
local loop dobrze
DCE
DTE
Devices on the subscriber premises are called customer premises equipment (CPE). The
subscriber owns the CPE or leases the CPE from the service provider. A copper or fiber cable
connects the CPE to the service provider’s nearest exchange or central office (CO).
9 A new international company needs to have a design for WAN connectivity. The company
will have at least five offices in every state in the United States and Mexico. Some states will
have as many as 20 offices. The branch offices will require constant contact with the services
of the main office. Which design model is best for WAN connectivity in this situation?
a mesh network of all branch WANs
a simple star topology connecting all branch LANs to a central router with multiple interfaces
a one layer design using Frame Relay links between LANs
a three layer hierarchical topology interconnecting branch LANs within an area, the area
LANs within a region, and connecting the regions to form the core of the WAN
10 Which of the statements regarding DSL are correct? (Choose three.)
DSL provides a consistent bandwidth of 2.154 Mbps.
DSL connections provide a fast dialup to establish a WAN connection.
DSL connects the local loop to a digital subscriber line access multiplexer.
DSL bandwidth varies and can exceed the bandwidth of a T1/E1 leased line.
For DSL to function properly, the local loop must be less than 5.5 kilometers (3.5 miles).
DSL is a popular choice for enterprises that need to connect home users to the local network
due to strong security.
The different varieties of DSL provide different bandwidths, with capabilities exceeding those of a T1
or E1 leased line. The transfer rates are dependent on the actual length of the local loop and the type
and condition of its cabling. For satisfactory service, the loop must be less than 5.5 kilometers (3.5
miles). DSL availability is far from universal, and there are a wide variety of types, standards, and
emerging standards. It is not a popular choice for enterprise computer departments to support home
workers. Generally, a subscriber cannot choose to connect to the enterprise network directly, but must
first connect to an Internet service provider (ISP). From here, an IP connection is made through the
Internet to the enterprise. Thus, security risks are incurred.
11 Depending on the company size and geographical layout, there might be many end points
on the company WAN. Why is it important to identify all the end points of the WAN before
choosing a WAN design?
to determine the routing protocol to be used on the WAN link
to determine the WAN topology
to determine the requirements for latency and jitter
to determine the signaling protocol to be used on the WAN link
12 Which of the following is true of WANs?
Shared network WAN technologies such as Frame Relay and ATM are more expensive but
offer less latency and jitter than dedicated lines.
ISDN is suitable for large enterprises.
The more network devices that data has to pass through across the WAN, the more latency
and less reliability the network will experience.
WANs typically incorporate only one technology such as ISDN, Frame Relay, or
ATM.
In selecting a layout, there are several factors to consider. More links will increase the cost of the
network services, and having multiple paths between destinations increases reliability. Adding more
network devices to the data path will increase latency and decrease reliability.
13 A large company already has a T1 leased line but this connection is inadequate at peak
business hours. Furthermore, they would like a backup WAN connection in case their leased
line temporarily fails. What type of WAN connection is commonly used in this situation?
X.25
DSL
ISDN
cable modem
56 kbps
14 A European company needs a low cost, dialup WAN connection to validate transactions
for point-of-sale card readers. Which connection type is commonly used for this situation?
ATM
X.25
Frame Relay
Leased lines
15 Why is it important to identify the type of traffic that will be carried on the WAN links
before choosing a WAN technology?
to determine the routing protocol to be used on the WAN link
to determine the WAN topology
to determine the requirements for latency and jitter
to determine the type of signaling protocol to be used on the WAN link
. WANs carry a variety of traffic types with varying requirements for bandwidth, latency, and jitter.
16 A U.S. company requires a WAN connection used only to transfer sales data from
individual stores to the home office. All transfers will occur after business hours. The required
bandwidth for this connection is estimated to be less than 38 kbps. Which type of connection
requires the least investment for this company?
ATM
ISDN
analog dialup
T1 Leased Line
1
Which command was used to display the partial output shown in the graphic?
show ppp traffic
show lcp traffic
debug ppp negotiation
debug ppp authentication
2 Which authentication protocol can be spoofed to allow playback attacks?
MD5
CHAP
PAP
NCP
PAP is not a strong authentication protocol. Passwords are sent across the link in clear text and there
is no protection from playback or repeated trial-and-error attacks. The remote node is in control of the
frequency and timing of the login attempts
CHAP provides protection against playback attack through the use of a variable challenge value that is
unique and unpredictable. Since the challenge is unique and random, the resulting hash value will also
be unique and random.
3 A two router network is running PPP over the serial interfaces that connect them. The
enable password on the Denim router is "gateway". The Denim router also has a locally
configured authentication password for the Plaid router which is "fortress". Which command
must be executed on the Plaid router to allow Denim to authenticate to the Plaid router using
CHAP?
Plaid(config)# enable secret gateway
Plaid(config)# enable secret fortress
Plaid(config)# username Plaid password fortress
Plaid(config)# username Denim password fortress
Plaid(config)# hostname Plaid secret password gateway
Plaid(config)# hostname Plaid secret password fortress
4
Refer to the output of the show interface Serial0/0 command in the graphic. How many NCPs
have been established?
1
2
3
4
5 How is the MD5 function valuable in authentication? (Choose two.)
uses a one-way hash function
authentication occurs more rapidly
challenges are unique
the remote router assumes control of frequency of challenge
the remote router assumes control of timing of challenge
After the PPP link establishment phase is complete, the local router sends a "challenge" message to
the remote node. The remote node responds with a value calculated using a one-way hash function,
which is typically Message Digest 5 (MD5). This response is based on the password and challenge
message. The local router checks the response against its own calculation of the expected hash
value. If the values match, the authentication is acknowledged, otherwise the connection is
immediately terminated.
6 Which command specifies a link quality over a PPP link?
ppp link 50
ppp link quality 60
ppp percentage 80
ppp quality 90
7 Which advantage does the multilink option provide when using PPP?
Data transmission has load balancing possibilities.
Interfaces can be configured using both HDLC and PPP.
More than one authentication method can be used.
More than one compression protocol can be configured.
Multilink - Cisco IOS Release 11.1 and later supports multilink PPP. This alternative provides load
balancing over the router interfaces that PPP uses.
8
What can be concluded from the output shown in the graphic? (Choose three.)
A two-way handshake is occuring.
The LCPs were already negotiated.
The router can begin NCP negotiations.
The debug ppp negotiation command was executed.
The debug ppp authentication command was executed.
9 Which of the following is a reason for using such protocols as PAP and CHAP?
to establish a PPP session
to provide error checking on a WAN link
to restrict access to networks connected by serial and ISDN links
to provide a backup hostname and privilege mode password on the router
10 A technician is testing the functionality of a recently installed router. The technician is
unable to ping the serial interface of a remote router. The technician executes the show
interface serial 0/0 command on the local router and receives the following output:
Serial0/0 is up, line protocol is down(disabled)
What are possible causes for this command output? (Choose two.)
interface missing the no shutdown command
clockrate command missing
CSU/DSU failed
interface shutdown due to high error rate
cable missing
11 Which of the following is an advantage of using time-division multiplexing (TDM) for
transmitting data? (Choose two.)
It allows a single source to transmit over multiple data channels.
Multiple sources can transmit over a single channel.
Original data streams must be reconstructed at the destination.
TDM relies on Layer 3 protocols to operate.
the example shown in Figure , there are three sources of information carried in turn down the output
channel. First, a chunk of information is taken from each input channel
12 ISDN BRI service uses two B channels to send data, voice, and video. If the first channel
becomes saturated, the second channel can be configured to forward packets. Which
command will allow ISDN to load balance across both links?
Router(config-if)# ppp quality 2
Router(config-if)# ip variance
Router(config-if)# ip maximum-paths 2
Router(config-if)# ppp multilink
13 When troubleshooting the Serial 0/0 interface of a router, a technician issues the show
controllers command. The following was the output of the command:
Interface is Serial0/0, electrical interface is UNKNOWN.
What can be concluded about the Serial 0/0 interface? (Choose three.)
Serial0/0 is down, line protocol is down
Serial0/0 is down, line protocol is up
Serial0/0 is up, line protocol is down
The interface is neither DCE or DTE.
The interface hardware may be faulty.
The cabling may be improperly connected.
If the electrical interface output is shown as UNKNOWN, instead of V.35, EIA/TIA-449, or some other
electrical interface type, an improperly connected cable is the likely problem. A problem with the
internal wiring of the card is also possible. If the electrical interface is unknown, the corresponding
display for the show interfaces serial <X> command will show that the interface and line
protocol are down.
14 PPP uses several protocols for communication. Which of the following are options that the
LCP protocol in the PPP architecture can provide? (Choose two.)
testing the quality of the link
routing packets between devices
assigning individual station addresses
configuring network layer protocols
negotiating authentication options
15 Several tasks must occur before a link between two routers can pass data using PPP.
Which of the following are required to establish and maintain a PPP session between two
routers?
configure each host with a PPP address
configure authentication between the two routers
send LCP and NCP frames to negotiate configuration parameters
send hostname and password information between the two routers
16 A technician has used Telnet to gain remote access to a router that has no connectivity on
its serial interface. Which command should be issued to determine if the serial cable is
connected properly?
show controllers
show processes
show run
show status
17 Which of the following describes the CHAP protocol? (Choose three.)
exchanges a random challenge number during the session to verfiy identity
sends authentication password to verify identity
prevents transmission of login information in plain text
disconnects the PPP session if authentication fails
initiates a two-way handshake
18 Which of the following describe functions of the Point-to-Point protocol with regards to
the OSI model? (Choose three.)
PPP uses Layer 3 of the OSI model to establish and maintain a session between devices.
PPP operates at all layers of the OSI model.
PPP uses the data link layer to configure such options as error detection and compression.
PPP provides a mechanism to multiplex several network layer protocols.
PPP uses Network Control Protocols (NCP) to test and maintain connectivity between
devices.
PPP can be configured on both synchronous and asynchronous serial interfaces.
19 How did Cisco alter the HDLC encapsulation to allow a single link to carry multiple
protocols?
split the transmissions into multiple channels each carrying a single protocol
identified the protocol in the FCS field
compressed the datagrams differently for each protocol
added a type field to identify the protocol
The Cisco HDLC frame uses a proprietary 'type' field that acts as a protocol field Standard HDLC
does not inherently support multiple protocols on a single link, as it does not have a way to indicate
which protocol is being carried. Cisco offers a proprietary version of HDLC.
20 Which of the following describes the High-Level Data Link Control protocol? (Choose
three.)
HDLC provides flow and error control.
Standard HDLC supports multiple protocols on a single link.
HDLC uses sequencing and acknowledgements.
HDLC is defined as the default encapsulation on Cisco LAN interfaces.
Cisco implemented a proprietary version of HDLC.
Standard HDLC does not inherently support multiple protocols on a single link, as it does not have a
way to indicate which protocol is being carried. Cisco offers a proprietary version of HDLC. The Cisco
HDLC frame uses a proprietary 'type' field that acts as a protocol field. This field enables multiple
network layer protocols to share the same serial link. HDLC is the default Layer 2 protocol for Cisco
router serial interfaces.