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642-821 (BCRAN®)

TestKing's Building Cisco® Remote Access Networks

Version 1.0



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Reference: Building Cisco Remote Access Networks (Ciscopress) page 31

QUESTION NO: 3

What are the advantages of Frame Relay connection over dedicated leased lines? (Choose two)

A. Better suited multiple branch locations.B. Lower cost.

C. More control over the connection.

D. Full guaranteed bandwidth.

Answer: B, C

Explanation:

Frame Relay provides virtual circuit connectivity for enterprise networks that require 56 kbps up to T1/E1

speeds. It costs less than leased lines because it uses statistical multiplexing of packets to gain efficiencies

within the network, at the cost of a less-stringent bandwidth and latency guarantee. Frame Relay is being widelydeployed in enterprise networks to connect regional and branch offices into the enterprise backbone.

Reference:

http://www.cisco.com/en/US/products/hw/modules/ps2033/products_white_paper09186a0080091ca9.shtml

QUESTION NO: 4

On an EIA/TIA-232 null modem cable with DB25 connectors, which two pins are cross connected?

(Choose two)

A. Pin 2

B. Pin 3C. Pin 4

D. Pin 5

E. Pin 7F. Pin 8

Answer: A, B

Explanation:

Null modems crisscross DB-25 pins 2, 3 and other corresponding pins so that the two DTE devices cancommunicate. Some devices can be configured to operate either like a DTE or a DCE. Configuring a device as a

DCE usually means that it receives data on pin 2 and transmits data on pin 3.




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QUESTION NO: 5

Which WAN connections are typically employed at telecommuter sites? (Choose three)

A. Asynchronous dial-up

B. ISDN BRIC. Leased linesD. HDSL

E. Cable modems

F. ADSL

Answer: A B F

Explanation:

Typical WAN connections employed at telecommuter sites are as follows:

• Asynchronous dial-up

•

ISDN BRI• Frame Relay (leased line)


QUESTION NO: 6

Which statement describes the differences between IPSec and Cisco Encryption Technology (CET)?

A. CET supports AH, ESP and Anti-Replay which are not available with IPSec.

B. IPSec supports AH, ESP and Anti-Replay which are not available with CET.

C. CET is the implementation of IPSec in the Cisco Secure Services package.

D. IPSec is used to encrypt IP-only packets, whereas CET is used to encrypt only non-IP packets.

Answer: B

Explanation:

If you require only Cisco router-to-Cisco router encryption, then you could run CET, which is a more mature,

higher-speed solution.

If you require a standards-based solution that provides multivendor interoperability or remote clientconnections, then you should implement IPSec. Also, if you want to implement data authentication with or

without privacy (encryption), then IPSec is the right choice.

Reference:http://www.cisco.com/en/US/products/sw/iosswrel/ps1831/products_configuration_guide_chapter09186a00800

d981b.html#77018



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QUESTION NO: 7

When using a CATV cable service as an Internet connection medium, what is “upstream traffic”?

A. Traffic getting at the user’s home traveling to the headend.B. Traffic between the headend and the supplier antenna.

C. Broadcast traffic, including the cable TV signals.D. Traffic from outside the local cable segment serving the user’s home.

Answer: A

Explanation:

In the upstream direction (subscriber cable modems transmitting towards the head-end) the environment is

many transmitters and one receiver. This introduces the need for precise scheduling of packet transmissions to

achieve high utilization and precise power control so as to not overdrive the receiver or other amplifier electronics in the cable system. Since the upstream direction is like a single receiver with many antennas, the

channels are much much more susceptible to inter-fering noise products [5, 6] . In the cable industry, we

generally call this ingress noise...00000000000000

Reference:

http://www.cisco.com/en/US/about/ac123/ac147/ac174/ac202/about_cisco_ipj_archive_article09186a00800c837c.html

QUESTION NO: 8

Which feature will cache routes learned by dynamic routing protocols, enabling their use over DDR

connections?

A. Route redistribution

B. Dynamic static routesC. Snapshot routing

D. DDR route maps

E. Passive interfaces

Answer: A

Explanation:

On the corporate side, it is very important that you be able to distribute those addresses across the network, as

desired. To redistribute those routes, you need to configure the routes to be redistributed to a dynamic routing protocol at the core side.




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QUESTION NO: 9

Which statement is true regarding the ADSL (G.Lite G.922.2) standard?

A. Signals cannot be carried on the same wire as POTS signals.

B. It offers equal bandwidth for upstream and downstream data traffic.C. It was developed specifically for the consumer market segment requiring higher download speeds.D. It has limited operating range of less than 4,500 feet.

Answer: C

Explanation:

Asymmetric Digital Subscriber Line (ADSL) is designed to deliver more bandwidth downstream (from the

central office to the customer site) than upstream. Downstream rates range from 1.5 to 9 Mbps, whereasupstream bandwidth ranges from 16 to 640 kbps. ADSL transmissions work at distances up to 18,000 feet

(5,488 meters) over a single copper twisted pair.

Reference: http://www.cisco.com/en/US/tech/tk175/tk15/tech_protocol_family_home.html

QUESTION NO: 10

Which statement is true regarding uninteresting traffic being carried over a DDR link?

A. Uninteresting traffic will keep DDR call established, even if no more interesting traffic is being routed

over the link.B. Uninteresting traffic will be routed over an established DDR call, but at a lower priority than interesting

traffic.

C. Uninteresting traffic will not be routed over an established DDR call.D. Uninteresting traffic will be routed over an established DDR call, as long as there is enough interesting

traffic to keep the call connected.

Answer: C

Explanation:

Packets that are permitted entry according to the access list are identified as interesting or packets of interest .

Packets that are not permitted entry or are denied entry by an access list are deemed uninteresting .

Reference:

http://www.cisco.com/en/US/products/sw/iosswrel/ps1820/products_configuration_guide_chapter09186a00800

87504.html



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QUESTION NO: 11

What is the default action of authentication when AAA is enabled but authentication is not set?

A. Allow a user to access all resources after login.

B. Disallow a user from access to all resources after login.C. Record all access of resources and how long the user accessed each resources.D. Not to record any access of resources after login.

E. Allow any user to login without checking the authentication data.

F. Disallow any user from logging in with or without a valid username and password.

Answer: F

Explanation:

If authentication is not specifically set for a line, the default is to deny access and no authentication is

performed.


QUESTION NO: 12

Drag the queuing method from the list on the right to the appropriate description on the right.

Note: not all options will be used.

Answer:



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Explanation:

• Custom queuing – reserves a certain percentage of bandwidth for each specified class of traffic.

• Weighted fair queuing – prioritizes interactive traffics over file transfers to ensure satisfactoryresponse time for common user applications.

• Basic queuing – No such thing

• Priority queuing – ensures the timely delivery of a specific protocol or type of traffic becausethat traffic is transmitted before all others.


QUESTION NO: 13

Under which circumstance would use of Kerberos authentication system be required, instead of

TACACS+ or RADIUS?

A. Authentication, authorization and accounting need to use the a single database.B. Multiple level of authorization need to be applied to various router commands.

C. DES encrypted authentication is required.

D. The usage of various router functions needs to be accounted for by user name.

Answer: C

Explanation:

Kerberos is a client-server based secret-key network authentication method that uses a trusted Kerberos server

to verify secure access to both services and users. In Kerberos, this trusted server is called the key distribution

center (KDC). The KDC issues tickets to validate users and services. A ticket is a temporary set of electronic

credentials that verify the identity of a client for a particular service.

These tickets have a limited life span and can be used in place of the standard user password authentication

mechanism if a service trusts the Kerberos server from which the ticket was issued. If the standard user

password method is used, Kerberos encrypts user passwords into the tickets, ensuring that passwords are not



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sent on the network in clear text. When you use Kerberos, passwords are not stored on any machine, except for

the Kerberos server, for more than a few seconds. Kerberos also guards against intruders who might pick up the

encrypted tickets from the network.

Reference: http://www.cisco.com/en/US/tech/tk583/tk642/technologies_tech_note09186a0080094ea4.shtml

QUESTION NO: 14

Which of the following are examples of DTE devices? (Choose three)

A. Mainframe computer

B. CSU/DSU

C. Router D. Terminal

E. Modem

Answer: A C D

Explanation:

Data terminal equipment (DTE) are end devices such as PCs, workstations, routers, and mainframe computers.


QUESTION NO: 15

When the following configuration is present on the router, how many addresses will be available for

dynamic nat translation?

ip nat pool test 192.168.1.33 192.168.1.42 netmask 255.255.255.224 ip nat inside source list 7 pool test

A. 7B. 9

C. 10

D. 31

Answer: C

Explanation

The IP address that is configured for dynamic nat translation is 192.168.1.33 19 192.168.1.42 netmask

255.255.255.224

The start-ip is 192.168.1.33The end-ip is 192.168.1.42



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Start-ip – starting IP address that defines the range of addresses in the address pool.

End-ip – Ending IP address that defines the range of addresses in the address pool.


QUESTION NO: 16

What is the default encapsulation type set on Cisco router serial interfaces?

A. Frame Relay

B. HDLC

C. PPP

D. LAPB

Answer: BExplanation:

HDLC is the default encapsulation type on point-to-point, dedicated links. It is used typically when

communicating between two Cisco devices. It is a bit-oriented synchronous data link protocol. HDLC specifiesa data-encapsulation method on synchronous data links using frame characters and checksums.


QUESTION NO: 17

Which six AAA accounting types will a TACACS+/RADIUS server record?

A. Network, interface, exec, protocol, system, and resourceB. Resource, interface, connection, system, command, and network

C. Command, system, exec, network, connection, and resource

D. Connection, protocol, system, network, command, and resourceE. Crypto, system, network, protocol, command, and resource

Answer: C

Explanation:

system - Enables accounting for all system-level events not associated with users, such as reloads

network - Enables accounting for all network-related requests, including SLIP, PPP, PPP network control

protocols, and ARAP

connection - Enables accounting for outbound Telnet and rlogin

exec - Enables accounting for EXEC processes (user shells)

command - level Enables accounting for all commands at the specified privilege level



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Reference:

http://www.cisco.com/en/US/products/sw/secursw/ps4911/products_user_guide_chapter09186a00800eb6ce.ht

ml

QUESTION NO: 18

Which two are characteristics of Frame Relay? (Choose two)

A. Medium cost

B. High reliability

C. Circuit-switched

D. Branch site connectivity

Answer: B, DExplanation:

Frame Relay provides virtual circuit connectivity for enterprise networks that require 56 kbps up to T1/E1

speeds. It costs less than leased lines because it uses statistical multiplexing of packets to gain efficiencieswithin the network, at the cost of a less-stringent bandwidth and latency guarantee. Frame Relay is being widely

deployed in enterprise networks to connect regional and branch offices into the enterprise backbone.

Reference:

http://www.cisco.com/en/US/products/hw/modules/ps2033/products_white_paper09186a0080091ca9.shtml

QUESTION NO: 19

Which two WAN connections provide a single pre-established switched circuit reserved for the private

use of the customer? (Choose two)

A. Digital cable

B. T1 leased line

C. ISDND. Asynchronous dial-in

E. 56K dedicated line

Answer: C, D

Explanation:



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Circuit switching is a WAN-switching method, in which a dedicated physical circuit through a carrier network

is established, maintained and terminated for each communication session. Initial signal at the setup stage

determines the endpoints and the connection between the two endpoints.

Typical circuit switched connections are as follows:

• Asynchronous serial

•

Integrated Service Digital Network (ISDN), Basic Rate Interface (BRI), and ISDN Primary rateInterface (PRI)

Reference: Building Cisco Remote Access Networks (Ciscopress) page 20 21

QUESTION NO: 20

Which three are responsible of IKE in the IPSec protocol? (Choose three)

A. Negotiating protocol parameters

B. Packet encryptionC. Exchanging public keys

D. Integrity checking user hashes

E. Authenticating both sides of a connection

F. Implementing tunnel mode

Answer: A, C, E

Explanation:

IKE is a protocol used by IPSec for completion of Phase 1. IKE negotiates and assigns SAs for each

IPSec peer, which provide a secure channel for the negotiation of the IPSec SAs in Phase 2. IKE provides

the following benefits:• Eliminates the need to manually specify all the IPSec security parameters at both peers

• Lets you specify a lifetime for the IKE SAs

• Allows encryption keys to change during IPSec sessions

• Allows IPSec to provide anti-replay services

• Enables CA support for a manageable, scalable IPSec implementation

• Allows dynamic authentication of peers

Reference:

http://www.cisco.com/en/US/products/sw/secursw/ps2120/products_configuration_guide_chapter09186a00801

7278c.html#39982

QUESTION NO: 21



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Frame Relay describes the interconnection process between which two types of equipment?

A. DTE and DTE

B. DCE and DCEC. CPE and DTE

D. CPE and DCE

Answer: D

Explanation:

Frame relay defines the interconnection process between your customer premises equipment (CPE- also known

as data terminal equipment [DTE]) such as a router, and the service provider’s local access-switching

equipment (known as data communications equipment [DCE]).


QUESTION NO: 22

Drag and drop the ISDN in the options column to the related term in the target column.

Answer:



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Explanation:

U interface – defines the two-wire interface between the NT and the ISDN cloud.

TE1 – designates a device that is compatible with the ISDN network.

R interface – defines the interface between the TA and an attached non-ISDN device (TE2).S/T interface – is a four-wire interface (TX and RX).

TE2 – designates a device that is not compatible with ISDN and requires a terminal adapter.

Reference: Building Cisco Remote Access Networks (Ciscopress) page 171-173

QUESTION NO: 23

What is a benefit of choosing an Internet-based VPN over a point-to-point T1 connection?

A. VPNs offer more local control of the quality of service.B. VPN users are not tied to a specific fixed location.

C. VPNs can provide reserved bandwidth for the individual user.

D. VPNs offer better queuing mechanisms than T1 connections.

Answer: B

Explanation:

VPNs enables today’s increasingly mobile workforce to connect to their corporate intranets or extranets

whenever, wherever, or however they require; improving productivity and flexibility while reducing access

costs.


QUESTION NO: 24



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An Internet Service Provider is offering ADSL connections to its customers, providing 640 kbps upload

and 4 Mbps download speeds.

Which customers would benefit from this type of connection? (Choose two)

A. Small home offices requiring 24 hour connection to the Internet for email and web communication.

B. Web services companies providing dynamic web content serving, including video-on-demand.C. Central data processing facilities receiving simultaneous uploads of data from remote offices.D. Support organizations providing ftp services for software distribution and documentation.

Answer: A, C

Asymmetric Digital Subscriber Line (ADSL) is designed to deliver more bandwidth downstream (from the

central office to the customer site) than upstream.

The remote sites using ADSL would benefit this for the downloading of data from the Central data processingfacility.

Reference: http://www.cisco.com/en/US/tech/tk175/tk15/tech_protocol_family_home.html

QUESTION NO: 25

Which of the following terminals can be connected to an ISDN line? (Choose two)

A. TO2B. TE1

C. TE2/TA

D. NU1

Answer: B, C

Explanation:

Terminal equipment 1(TE1) - Designates a device that is compatible with the ISDN network. A TE1 connects

to a Network Termination of either Type 1 or Type 2, such as a digital telephone, a router with ISDN interface,or digital facsimile equipment.

Terminal equipment 2(TE2) - Designates a device that is not compatible with the ISDN and requires a

terminal adapter, such as terminals with X.21, EIA/TIA-232, or X.25 interfaces or a router without a ISDNinterface (AGS= and so on).

Terminal adapter – converts standard electrical signals into the form used by ISDN, so that non-ISDN devices

can connect to the ISDN network.




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QUESTION NO: 26

Which two statements about Frame Relay subinterface configurations are true? (Choose two)

A. Any IP address must be removed from the subinterface.B. Subinterface is configured either multipoint or point-to-point.

C. The physical interface and subinterface can each be configured with IP addresses.D. The configuration must be added to the D channel.

Answer: B

Explanation:


QUESTION NO: 27

When configuring an asynchronous line, what is the result of issuing the flowcontrol hardwarecommand?

A. It sets RAM aside to buffer incoming and outgoing data.B. It sets the line to use CTS/RTS flow control.

C. It sets the modem to handle flow control instead of the router.

D. It sets the modem to use MNP4 firmware.

Answer: B

Explanation:

flowcontrol hardware – Uses RTS/CTS for flow control.


QUESTION NO: 28

Which statements are true regarding the command telnet 10.10.30.4 2009? (Choose two)

A. It is used to reverse Telnet connection.

B. It is used to Telnet to port 2009 on a specific computer.C. A modem is connected to line 9.

D. It specified a BRI connection to be used for Telnet.

Answer: B, C



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Explanation:

Answer B. Telnet protocol uses 2000 base TCP port for individual lines.

Answer C. TTY lines 1 through 24 directly connect to modems 1/0 through 1/23, which are installed in the firstchassis slot in this example. The TTY lines 25 through 48 directly connect to modems 2/0 through 2/23, which

are installed in the second slot. Reference: Building Cisco Remote Access Networks (Ciscopress) page 70


ca657.html

QUESTION NO: 29

When using PPPoE to communicate over a DSL service connection, which process must be performed by

the host to establish a PPPoE SESSION_ID?

A. A Bootp process to request a configuration and session ID.B. A Discovery process to identify a PPPoE server and request a session ID.

C. A DHCP request process to request and IP address and session ID.

D. A RARP request process to request a MAC address and session ID.

Answer: B

Explanation:

When a host wishes to initiate a PPPoE session, it must first perform discovery to identify the Ethernet MAC

address of the peer and establish a PPPOE SESSION_ID. Although PPP defines a peer-to-peer relationship,discovery is inherently a client/server relationship. In the discovery process, a host (the client) discovers an

access concentrator (the server). Based on the network topology, there may be more than one access

concentrator that the host can communicate with. The Discovery Stage allows the host to discover all accessconcentrators and then select one. When discovery is completed, both the host and the selected access

concentrator have the information they will use to build their point-to-point connection over Ethernet.

Reference:

http://www.cisco.com/en/US/products/sw/iosswrel/ps1834/products_feature_guide09186a008007fe7d.html

QUESTION NO: 30

Which physical factors can reduce the maximum speed available on a DSL connection? (Choose two)

A. Lack of loading coils and the subscriber’s line.

B. Distance from the CPE to the DSLAM.C. Gauge of wire used on the local loop.



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D. Number of telephones attached to the local loop.

E. Lack of bridge taps in the local loop.

Answer: D, E

Determine if the local loop is too long. The maximum length range is 15,000 to 25,000 feet (4572 to7620 meters). Within that range, wire gauge, cross talk, and multiple bridge taps reduce the distance over whichthe modems can train.

Reference: http://www.cisco.com/en/US/products/hw/switches/ps298/products_installation_guide_chapter09186a008007c8

fb.html

QUESTION NO: 31

A network administrator would like to use an existing ISDN line as a backup for a Frame Relay lineconnected on interface serial0.

Which statement is correct based on the following configuration of the Cisco Router?

interface serial0

ip address 192.168.10.1 255.255.255.0

backup interface bri0

backup delay 5 10

interface bri0

ip address 192.168.11.2 255.255.255.0

dialer idle-timeout 900

dialer-group 1

dialer-group 1 protocol ip permit

A. ISDN BRI line will be in “standby” mode after 900 seconds once the serial interface activates again.B. ISDN BRI line will be in “standby” mode after 10 seconds once the serial interface activates again.

C. ISDN BRI line will be in “standby” mode after 10 seconds but will be in “standby” mode after 900

seconds once the serial interface activates again.D. ISDN BRI line will be in “standby” mode after 10 seconds but will be in “up/ip” mode after 900 seconds

once the serial interface activates again.



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Answer: C

Explanation:

- backup delay 5 10 command:

backup delay enable-delay disable-delay

Specify delay between the physical interface going down and the backup being enabled, and between the physical interface coming back up and the backup being disabled.

- dialer idle-timeout 900

This command specifies the time that the line can remain idle before it is disconnected.

Reference:


8721f.html

QUESTION NO: 32Which three of the following router IOS commands defines “interesting” traffic for only one host using

dial on command routing (DDR) (Choose three)

A. RTA(config)#dialer-list 1 protocol ip permit 10.1.1.1

B. RTA(config)#access-list 2 permit host 192.168.1.12

C. RTA(config-if)#dialer-group 1 D. RTA(config)#dialer-group 2

E. RTA(config)#dialer-list 1 protocol ip list 2

F. RTA(config-if)#dialer-list 2 protocol ip permit

Answer: A B E

Explanation:

Define what constitutes interesting traffic by using the dialer-list command.

The access-list command specifies interesting traffic that initiates a DDR call.These commands are assigned on the global configuration line.

The dialer-group command needs to be assigned to the interface responsible for initiating the call.


QUESTION NO: 33

Which command will change the specified Frame Relay encapsulation for a specific PVC on an interface?

A. no frame-relay encapsulation ietf



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B. no frame-relay encapsulation cisco

C. encapsulation frame-relay ietf

D. frame-relay map ip 10.160.2.1 100 broadcast ietf

Answer: DExplanation:

The default encapsulation, which is Cisco, is applied to all the VCs available on that serial interface. If most

destinations use the Cisco encapsulation, but one destination requires the IETF, you would specify, under the

interface, the general encapsulation to be used by most destinations. Because the default encapsulation is Cisco,you would specify the exception using the frame-relay map command.


QUESTION NO: 34

A system administrator issues a Router(config)#aaa new-model command from a telnet session.Making no other changes, the administrator saves the configuration to nvram and then exists the telnet

session. No local username/password database exists on the router.

What will happen when the administrator tries to immediately establish another telnet session? (Choose

two)

A. The session asks for a username that may not exist.

B. The router requires a reboot so the administrator can login.C. The administrator must access the router though the console port to login.

D. The administrator can log in without using a password.

Answer: A, C

Explanation:

On console, login will succeed without any authentication checks if default is not set.

If authentication is not specifically set for a line, the default is to deny access and no authentication is

performed.


QUESTION NO: 35

Given the following configuration statement, which two statements are true? (Choose two)

router(config)#aaa authentication login default group tacacs+ none

A. No authentication is required to login.



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B. TACACS+ is the first default authentication method.

C. Uses the list of TACACS+ servers for authentication, if TACACS+ fails then no access is permitted.

D. Uses the list of servers specified in group “TACACS+”, if none are available, then no access is

permitted.E. Uses the list of TACACS+ servers for authentication, if TACACS+ fails then uses no authentication.

F. Uses a subset of TACACS+ servers named “group” for authentication as defined by the aaa groupservers tacacs+ command.

Answer: B, E

Explanation:

To create a default list that is used if no list is assigned to a line, use the authentication login command with the

default argument, followed by the methods you want to use in default situations.

The additional methods of authentication are used only if the previous methods returns an error; not if it fails.

Specify none as the final method in the command line to have authentication succeed. if all methods return an

error.Additional methods:

• Enable

• Krb5

• Line

• Local

• None

• Radius

• Tacacs+

• Krb5-telnet


QUESTION NO: 36

Exhibit:

From the figure, which command establishes how Cisco-1 will call Cisco-2?

A. dialer map ip 10.120.1.1 name Cisco-1 4085552222



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B. dialer map ip 10.120.1.2 name Cisco-1 4085551111

C. dialer map ip 10.120.1.2 name Cisco-2 4085552222

D. dialer map ip 10.120.1.2 name Cisco-2 4085551111

Answer: CExplanation:

dialer map protocol net-hop address [name hostname] broadcast] dial-string

This command configures a serial interface or ISDN interface to call one or multiple sites. The name refers to

the name of the remote system, and broadcast indicates that broadcast should be forwarded to this address. Thedial-string is the number to dial to reach the destination.


QUESTION NO: 37You are the network administrator at TestKing.com. A boarding supply store's manager within the

company needs access from home to the store's internal network. You are asked to their router enabling

it to accept asynchronous connections through a modem. It is your task to configure the serial port S0/1

for asynchronous communication and to enable a reverse telnet session to the attached modem. No other

router or modem configuration is necessary at this time. Your task is complete when you are able to

reverse telnet to the modem and issue an AT command to begin modem configuration.

Task steps:

• Configure S0/1 to Asynchronous communication

• Set the line speed to 33.6K

•

Set the flow control to hardware • Set the stop bits to one

• Set the line password to "testking"

• Configure the line to allow for both incoming and outgoing calls

• Allow all protocols for incoming connections on the line.

• Configure the Loopback address to 192.168.0.1/32.

• Reverse telnet to the modem

• Issue an AT command, modem should respond with OK.

To configure the router clock on a host icon that is connected to a router by a serial console cable.



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Answer:

QUESTION NO: 38

Which commands are configured from the line configuration mode? (Choose three)

A. encapsulation pppB. async mode interactive

C. modem inout

D. speed 115200

E. flowcontrol hardware

Answer: C, D, E

Explanation:

• modem inout - Uses the modem for both incoming and outgoing calls.

• speed 115200 – Sets the maximum speed (in bits-per-second) between the modem and the access server.

• flowcontrol hardware – Uses RTS/CTS for flow control.


QUESTION NO: 39



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Which command is used to enable asynchronous dialup on a serial interface?

A. physical-mode async

B. dialer-group layer asyncC. physical-layer async

D. modem inout

Answer: C

Explanation:

Physical-layer async – configures the serial interface as an async interface.


QUESTION NO: 40Which command will allow a router to attempt to discover the modem to which it is attached?

A. modem autoconfigure discovery

B. modem discovery autoconfigure

C. modem autoconfigure type discovery

D. modem discovery type autoconfigure

Answer: A

Explanation:

If no modem is specified for a particular line and you have provided the modem autoconfigure discovery

command, the access server attempts to autodiscover the type of modem to which it is attached. The accessserver determines the type of modem by sending AT commands to the modem and evaluating the response.


QUESTION NO: 41

The network administrator enables Frame Relay traffic shaping and configures a CIR of 64kbps.

Using 125ms time interval, what will be the value of the committed burst (Bc)

A. 32000 bits

B. 24000 bits

C. 16000 bits

D. 8000 bits



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Answer: D

Explanation:

The calculation is TC = Bc/CIR

125ms (tc) = 8000bits (Bc)/64kbps (CIR)


QUESTION NO: 42

What happens when the command clear ip nat translation is entered on a router?

A. Clears all existing NAT translation table entries and NAT is suspended.B. Clears dynamic NAT translation table entries and NAT resumes.

C. Clears static NAT translation entries and NAT resumes.

D. Clears all inactive NAT translation entries and NAT is suspended.

Answer: A

Explanation:

Clears dynamic NAT translations from the translation table


QUESTION NO: 43

By which two methods can callers be authenticated using PPP? (Choose two)

A. Message digest key

B. Authentication key

C. PAPD. CHAP

Answer: C, D

Explanation:

Authentication, using either PAP or CHAP, is used as a security measure with PPP and PPP callback.Authentication allows the dial-up target to identify that any given dial-up client is a valid client with a

preassigned username and password.




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QUESTION NO: 46

Which two commands would be useful to troubleshoot ISDN Layer 3? (Choose two)

A. debug isdn q931B. debug isdn network C. debug isdn q921

D. debug isdn event

Answer: A, D

Explanation:

• You may use the debug isdn q931 EXEC command to display information about call setup andteardown of ISDN network connections (Layer 3) between the local router (user side) and the network.

•

The debug isdn events command also displays information that is useful for monitoring andtroubleshooting Multilink PPP.

Reference: Building Cisco Remote Access Networks (Ciscopress) page 209, 210

Incorrect Answers

B: Not a valid command

C: Troubleshoots ISDN layer 2

QUESTION NO: 47Which of the following are used to verify and troubleshoot a PPP session? (Choose two)

A. show interfaces

B. show PPP

C. debug PPP negotiation

D. debug PPP session

Answer: A, C

Explanation:

•

Use the show interfaces command to display status and counter information about an interface.• The debug ppp negotiation command is a great tool for troubleshooting the PPP Link Control protocol

activities such as authentication, compression, and multilink.



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QUESTION NO: 48

Serial0 on a router is configured with the command encapsulation frame-relay.What can cause the output from the show interface command to indicate:

Serial0 is up, line protocol is down?

A. No carrier signalB. IP subnet mismatch

C. LAPF state, down

D. LMI type mismatch

E. No IP address configured

Answer: DExplanation:

"Serial0 is up, line protocol is down"

This line in the output means that the router is getting a carrier signal from the CSU/DSU or modem. Check to

make sure the Frame Relay provider has activated their port and that your Local Management Interface (LMI)

settings match. Generally, the Frame Relay switch ignores the data terminal equipment (DTE) unless it sees thecorrect LMI (use Cisco's default to "cisco" LMI). Check to make sure the Cisco router is transmitting data. You

will most likely need to check the line integrity using loop tests at various locations beginning with the local

CSU and working your way out until you get to the provider's Frame Relay switch.

Reference:

http://www.cisco.com/en/US/tech/tk713/tk237/technologies_tech_note09186a008014f8a7.shtml#serialupdown

QUESTION NO: 49

What occurs when there is no longer a signal on the DTR?

A. The CD tells the DTE that a DCE-to-DCE connection has been established.

B. The DTE issues a RTS to the DCE enabling communication.C. The DCE terminates its connection with the remote modem.

D. The DTE applies voltage on pin 20 to alert the DCE that it is connected and available to receive data.

Answer: C



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Explanation:

Either the DTE device or the DCE device may signal for the connection to be terminated. The signals that are

used for this function are DTR from the DTE or the modem recognizing the loss of the CD signal.


QUESTION NO: 50

Company TestKing has a hub and spoke Frame Relay network. No spoke router can ping any other

spoke routers, yet all spoke routers can pin the hub router.

What is a possible cause?

A. Disabled split horizon

B. Poison reverse issueC. Inverse ARP issue

D. Spanning-tree loop

Answer: C

Explanation:

Connecting from Spoke to Spoke

You cannot ping from one spoke to another spoke in a hub and spoke configuration using multipoint interfaces because there is no mapping for the other spokes' IP addresses. Only the hub's address is learned via the Inverse

Address Resolution Protocol (IARP). If you configure a static map using the frame-relay map command for the

IP address of a remote spoke to use the local data link connection identifier (DLCI), you can ping the addresses

of other spokes.

Reference:http://www.cisco.com/en/US/tech/tk713/tk237/technologies_tech_note09186a008014f8a7.shtml#topic2

QUESTION NO: 51

Which one of the following ranges is the Valid Dynamic TEI value assignment range for an ISDN BRI

circuit?

A. 1-24

B. 25-62

C. 64-126D. 128-256



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Answer: C

Explanation:

The TEI is a dynamic assignment to that device. IN the U.S., when you boot up a router, you make some type of

request to the switch for a TEI. The switch assigns you a TEI, and you will communicate over the switch usingthe signaling that uses a SAPI.

TEI group assignments are 0-63 for non automatic assignments; 64-126 for automatic TEI assignment; and127 for group assignment, or broadcast.


QUESTION NO: 52

Which router IOS command would generate the following information line?

kickin load 60% kickout load 40%

A. show primaryB. show backup

C. show load

D. show interface

E. show dialer-profile

Answer: D

Explanation:

Use the show interfaces command to display status and counter information about an interface.


QUESTION NO: 53

What are four PPP options that are negotiated using LCP? (Choose four)

A. Callback

B. Multilink

C. AccountingD. Compression

E. Authorization

F. Authentication

G. Rate adaptation



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Explanation:

dialer map protocol next-hop-address [name hostname] [broadcast] dialstring

This command configures a serial interface or ISDN interface to call one or multiples sites. The name refers to

the name of the remote system, and broadcast indicates that broadcasts should be forwarded to this address.This dial-string is the number to dial to reach the destination.


QUESTION NO: 56

Examine the partial output of the show run commandinterface BRI0

description connected to ntt 81019998887654

ip address 10.12.15.5 255.255.255.0

encapsulation ppp

dialer idle-timeout 30

dialer load-threshold 40 either

dialer map ip 10.12.15.8 name RTB 81019998888901

dialer map ip 10.12.15.9 name RTC 81019998881234

dialer map ip 10.12.15.4 name RTD 81019998881122

dialer-group 1

ppp authentication pap

ppp multilink

Which statement is true about the type of dial-on demand routing being implemented using BRI0?

A. By configuring legacy DDR on interface BRI0, calls made to all three sites will use the samecommunication parameters.

B. By configuring BRI0 as a member of a dial-group 1, communications parameters assigned to the group

will override those configured on the interface.C. Calls made using BRI0 will attempt to use the authentication configured for the dial rotary, and if

unsuccessful, will use pap authentication.

D. The dialer profile communication parameters will override those configured directly on interface BRI0.

Answer: A

QUESTION NO: 57What are two results of issuing the frame-relay map ip 192.168.1.2 100 command? (Choose two)

A. Inverse ARP is enabled.



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B. Inverse ARP is disabled.

C. Split horizon is enabled

D. Split horizon is disabled.

E. IP address 192.168.1.2 is dynamically mapped to DLCI 100.F. IP address 192.168.1.2 is statically mapped to DLCI 100.

Answer: B, F

Explanation:

If you use dynamic address mapping, Frame Relay Inverse ARP provides a given DLCI and requests next-hop protocol addresses for a specific connection. The router then updates its mapping table and uses the information

in the table to route outgoing traffic. Dynamic address mapping is enabled by default for all protocols on a

physical interface. If you use the static mapping, you must use the frame-relay map command to statically map

destination network protocol addresses to a designated DLCI.

Reference: Building Cisco Remote Access Networks (Ciscopress) page 346-347

QUESTION NO: 58

Given the following debug output, which two statements are true? (Choose two)

1d16h: %LINK-3-UPDPDOWN: Interface Serial3/0, changed state to up

*Mar 2 16:52:15.297: Se3/0 PPP: Treating connection as a dedicated line

*Mar 2 16:52:15.441: Se3/0 PPP: Phase is AUTHENTICATING, by this end

*Mar 2 16:52:15.445: Se3/0 CHAP: O CHALLENGE id 7 len 29 from “NAS1”

A. The user is authenticating with the privileged mode password “NAS1”.

B. This is a connection attempt to an async port.C. The connection is established on serial interface 3/0.

D. The client is attempting to setup a Serial Line Internet Protocol connection.

E. The user is authenticating using CHAP.

Answer: C E

Explanation:

When using Chap authentication, the access server sends a challenge message to the remote node after the ppp

link is established. The remote node responds with a value calculated by using a one-way hash function. The

access server (NAS1) checks the reponse against its own calculation of the expected hash value.




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QUESTION NO: 59

Given the configuration:access-list 101 permit ip any any

access-list 101 deny tcp any any eq ftp

dialer-list 2 protocol ip list 101

Which two statements about the configuration are true with respect to FTP traffic and DDR? (Choose

two)

A. FTP traffic will be forwarded.

B. FTP traffic will not be forwarded.

C. FTP will cause the line to come up.D. Since FTP uses two sockets, both must be defined to prevent packet forwarding.

Answer: B CExplanation:

• Access-list 101 deny tcp any any eq ftp - will stop any ftp traffic to any host

• dialer-list 2 protocol ip list 101 – command is used to configure dial-on-demand calls that will initiate

a connection.

Reference: Building Cisco Remote Access Networks (Ciscopress) page 187 - 194

QUESTION NO: 60

A Frame Relay PVC is reported as in INACTIVE state on the router.What is the possible cause?

A. PVC is not configured on local router.B. PVC is not configured on the Frame Relay switch.

C. PVC is in DOWN state on the remote router.

D. PVC is in DELETED state on the remote router.

Answer: C

Explanation:

Inactive state – Indicates that the Local connection to the Frame Relay switch is working, but the remote

router’s connection to the Frame Relay switch is not working.




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QUESTION NO: 63

Based on the configuration shown, what is the CIR of interface Serial0/0 300?

interface Serial0/0

no ip address

encapsulation frame-relayno fair-queue

frame-relay traffic-shaping

bandwidth 1536

!

interface Serial0/0.100 point-to-point

ip address 10.1.1.1 255.255.255.0

frame-relay interface-dlci 100

frame-relay class cisco

!


ip address 10.1.2.1 255.255.255.0


frame-relay class cisco

!


ip address 10.1.3.1 255.255.255.0


!

!

map-class frame-relay cisco

frame-relay cir 128000

frame-relay adaptive-shaping becn

A. 56 kbps

B. 64 kbps

C. 128 kbpsD. 896 kbps

E. 1536 kbps

Answer: C

Explanation:

frame-relay cir

To specify the incoming or outgoing committed information rate (CIR)for a Frame Relay virtual circuit, use the

frame-relay cir map-class configuration command. To reset the CIR to the default, use the no form of

this command.



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frame-relay cir {in | out} bps no frame-relay cir {in | out} bps

Reference:

http://www.cisco.com/en/US/products/sw/iosswrel/ps1824/products_command_reference_chapter09186a00800

87bcd.html#xtocid106829

QUESTION NO: 64

When is ISDN BRI a viable option as a remote access solution?

A. A mobile user that needs access to the central site while traveling.

B. A branch office needs to connect to a mobile user.

C. A remote site with sporadic traffic needs to connect to central site.D. A branch office requires at least 300kbps bandwidth to the central site.

Answer: CExplanation:

Basic Rate Interface (BRI) is an Integrated Systems Digital Network (ISDN) interface, and it consists of two B

channels (B1 and B2) and one D channel. The B channels are used to transfer data, voice, and video. The Dchannel controls the B channels.

ISDN uses the D channel to carry signal information. ISDN can also use the D channel in a BRI to carry X.25

packets. The D channel has a capacity of 16 kbps, and the X.25 over D channel can utilize up to 9.6 kbps.When this feature is configured, a separate X.25-over-D-channel logical interface is created. You can set its

parameters without disrupting the original ISDN interface configuration. The original BRI interface will

continue to represent the D, B1, and B2 channels.Because some end-user equipment uses static terminal endpoint identifiers (TEIs) to access this feature, static

TEIs are supported. The dialer understands the X.25-over-D-channel calls and initiates them on a new interface.X.25 traffic over the D channel can be used as a primary interface where low-volume, sporadic interactive

traffic is the normal mode of operation. Supported traffic includes IPX, AppleTalk, transparent bridging, XNS,

DECnet, and IP.This feature is not available on the ISDN Primary Rate Interface (PRI).

Reference:

http://www.cisco.com/en/US/products/sw/iosswrel/ps1826/products_configuration_guide_chapter09186a00800d9b8a.html

QUESTION NO: 65

Which user requirement is best served by an access server?

A. Mobile sales force requiring dial-in access.



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B. Mobile sales force requiring dedicated connection.

C. Corporate staff requiring access to web-bases applications.

D. Corporate staff requiring access to applications on corporate systems.

Answer: AExplanation:

A router act access server, which is a concentration point for dial-in and dial-out calls. Mobile users, for

example, can call into an access server at a Central site to access their messages.


QUESTION NO: 66

Which of the following statements are correct regarding the Multilink PPP protocol? (Choose two)

MLP can be applied to any link type utilizing PPP encapsulation.MLP can identify bundles only through the authenticated name.

MLP is a negotiated option only during the LCP phase of PPP.

For MLP to bind links, configuring AAA authentication is a required.

Answer: B

Explanation:

Answer A. Multilink PPP Prerequisites

The dialer interface, BRI interface, PRI interface, multilink interface, or virtual template must be configured,

and PPP encapsulation must be enabled.

Answer B. PPP authentication plays a part in Multilink PPP. The bundle decision is based on the authentication

name of the remote router independently on each side of the link. Each router should use a unqiue hostname for

authentication, with a shared password.


http://www.cisco.com/en/US/products/sw/iosswrel/ps1839/products_feature_guide09186a0080110bd7.html

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