05 Mei 2011 di 11.05 Diposkan oleh Dream Area 0 Comments

How many host addresses may be assigned on each subnetwork when using the 130.68.0.0 network address with a subnet mask of 255.255.248.0?
30
256
*2046
2048
4094
4096

In an IPv4 environment, what information is used by the router to forward data packets from one interface of a router to another?
*destination network address
source network address
source MAC address
well known port destination address

A company is developing an Internet store for its website. Which protocol should be used to transfer credit card information from customers to the company web server?
FTPS
HTTP
*HTTPS
WEP2
TFTP

How do port filtering and access lists help provide network security?
*They prevent specified types of traffic from reaching specified network destinations.
They alert network administrators to various type of denial of service attacks as they occur.
They prevent viruses, worms, and Trojans from infecting host computers and servers.
They enable encryption and authentication of confidential data communications.

A user reports being unable to access the Internet. The help desk technician employs a bottom-up approach to troubleshooting. The technician first has the user check the patch cable connection from the PC to the wall, and then has the user verify that the NIC has a green link light. What will the technician have the user do next?
Enter an IP address into the WWW browser address bar to see if DNS is at fault.
Use traceroute to identify the device along the path to the ISP that may be at fault.
*Verify the IP address, subnet, and gateway settings using ipconfig on the PC.
Connect to the user home router to check firewall settings for blocked TCP ports.

Refer to the exhibit. Which combination of cables and symbols is correct?
A - crossover, B - straight-through, C - straight-through
A - crossover, B - rollover, C - straight-through
*A - straight-through, B -crossover, C - straight-through
A - straight-through, B -straight-through, C - straight-through
A - straight-through, B - straight-through, C - crossover
A - rollover, B - straight-through, C - straight-through

Refer to the exhibit. Which command would an administrator use to configure the router name?
Router# ip hostname Boise
Router# hostname Boise
Router(config-line)# name Boise
*Router(config)# hostname Boise
Router> ip hostname Boise

How does a switch interface that uses sticky port security handle MAC addresses?
The addresses are configured manually and are saved in the running configuration.
They are configured manually and are not saved in the running configuration.
*They are configured dynamically and are saved in the running configuration.
They are configured dynamically and are not saved in the running configuration.

Which statement describes a feature of TCP?
It provides low overhead data delivery.
*It acknowledges the receipt of packets.
It does not provide error checking.
It is a connectionless protocol.

Which routing protocol facilitates the exchange of routing information between different autonomous systems?
OSPF
EIGRP
RIP
*BGP

Which statement is true about the reverse lookup DNS zone?
It is most commonly experienced when users are surfing the Internet.
It is the backup for the forward lookup zone.
It dynamically updates the resource records.
*It resolves an IP address to a fully qualified domain name.

Which statement correctly describes the function of AAA?
*It prevents unauthorized access to a network.
It filters traffic based on destination IP and port number.
It enables users to send information to a daemon that is running on a management station.
It encrypts data to provide network security.

Which two services are required to enable a computer to receive dynamic IP addresses and access the Internet using domain names? (Choose two.)
*DNS
WINS
HTTP
*DHCP
SMTP

A network administrator wants to configure six subnets for a Class C network. Which subnet mask will support the maximum number of hosts on each subnet?
255.255.255.248
255.255.255.240
*255.255.255.224
255.255.255.192

A building has experienced a power outage. When the power returns, none of the devices on one floor can access the Internet. The network administrator checks the switch in the IDF that these devices are connected to and notes that the SYST LED on the front of the switch is amber.
What is a possible cause of this problem?
The switch is functioning properly.
*The switch has failed POST.
The switch configuration file was not saved to NVRAM.
The connection between the switch and the server did not autonegotiate speed and duplex properly.


What is the effect of issuing the banner login #Unauthorized login prohibited# command on a router?
*It will display the message "Unauthorized login prohibited" before the router prompts for a user name.
It replaces the banner motd command.
It causes the router to prompt for login credentials for any user who is attempting to connect to the router.
It causes the message "Unauthorized access prohibited" to display when a HyperTerminal connection is idle.

Which statement correctly describes MIB?
It is software that is installed on a device which in turn is managed by SNMP.
It is installed on a system that is used to monitor networking devices.
*It is a database that a device keeps about itself concerning network performance parameters.
It is a communication protocol that is used between the management station and the management agent.

Which type of WAN connection uses a circuit-switched network?
*ISDN
Frame Relay
DSL
Cable

Refer to the exhibit. Which three IP addresses could be assigned to the hosts? (Choose three.)
192.168.88.1
192.168.88.8
*192.168.88.9
*192.168.88.12
192.168.88.14
192.168.88.15
*192.168.88.16
192.168.88.18

A network engineer is asked to specify the type of cable for a new network installation. The engineer plans horizontal cable runs of less than 90 feet (27.4 meters) using cable that is not expensive and is easy to implement. It will be positioned away from electrically noisy areas to avoid EMI. Which cable should the engineer choose?
STP
UTP
*coaxial
fiber optic

For the assignment of permissions to files and folders, what does the "principle of least privilege" imply?
No user has more privileges than any other user.
Permissions to files are given based on seniority.
*Users only have access to resources that are necessary for their jobs.
Users should be given no access to computer resources until they ask.

Which application can be delivered using UDP?
FTP
DNS
*HTTP
SMTP

Which technology is used for WAN connections and delivers up to 1.544 Mb/s of symmetrical bandwidth?
DSL
dialup
*T1 line
T3 line

Which WAN service provides point-to-point connections with a predefined communications path?
E1
T1
dialup
*leased line

What is the primary function of a Level 1 support technician in an ISP help desk department with multiple levels of customer support?
to install hardware replacements for the customer
to accompany an on-site technician to provide additional technical support
*to diagnose and document the symptoms of hardware, software, and system problems
to design network enhancements that support the new technology requirements of the customer

A user calls a help desk about being unable to connect to a web server. The technician asks the user to issue a ping 127.0.0.1 command. What is the purpose of this command?
verify if the network cable is connected to the PC
*verify if the TCP/IP stack is functioning on the PC
verify if the IP address is configured correctly on the PC
verify if the DNS server IP addresses are present on the PC

A small company is contracting with an ISP to host a web server. The web administrator needs to upload files to the web server via a secure channel using FTPS. Although a ping to the server is successful, the web administrator reports that the FTPS connection cannot be established. The technician at the ISP responds that for security reasons the FTPS default port has been blocked by a firewall and the web server has been configured with a non-default port for FTPS access. At which layer of the OSI model has the security measure been applied?
session layer
network layer
*transport layer
application layer

When a field technician visits a customer site and resolves the issue that was opened in a trouble ticket, what should the technician do?
assess the network design of the customer site
survey users at the customer site for further needs
*document the solution and obtain acceptance of the customer
discuss further problems that are identified during the visit and offer cost estimates


Refer to the exhibit. Static routes have been configured on all routers in the network. PC2 can communicate with PC1 but not with PC3. What should be done to remedy the problem?
Reconfigure the first static route with the exit interface S0/0/0.
*Reconfigure the second static route with the exit interface S0/0/1.
Reconfigure the first static route with the next hop address 172.16.3.1.
Reconfigure the second static route with the next hop address 172.16.3.1.

While configuring PAT on a Cisco ISR, a network technician defines the IP address of the router interface that connects to the ISP. This address will be the translated address for all Internet traffic from inside hosts. What is this IP address called?
inside local address
*inside global address
outside local address
outside global address

Refer to the exhibit. Which two routes when either is configured on R1 would allow traffic to be forwarded from hosts on network 192.168.10.0/24 to network 192.168.20.0/24? (Choose two.)
R1(config)# ip route 0.0.0.0 0.0.0.0 S0/0/1
*R1(config)# ip route 0.0.0.0 0.0.0.0 172.10.10.13
R1(config)# ip route 192.168.20.0 255.255.255.0 Fa0/0
*R1(config)# ip route 192.168.20.0 255.255.255.0 S0/0/0
R1(config)# ip route 172.10.10.12 255.255.255.252 192.168.20.0

In the URL http://dev.cisco.com/wwwdocs/procedures.htm, what is identified by wwwdocs?
the server name where the resource is located
the protocol that is used for the resource request
the domain name of the server that is being accessed
*the folder where the requested resource is stored

Refer to the exhibit. A technician uses the SDM application to configure router R1. Which step should be taken by the technician to enable the Fa0/0 interface on R1 to participate on the connected local network?
Enable a DHCP server on the Fa0/0 LAN interface.
*Configure the appropriate IP address on the Fa0/0 interface.
Configure IP addresses for the primary and secondary DNS server.
Configure the starting and ending IP addresses for the DHCP pool but exclude the Fa0/0 IP address.

Refer to the exhibit. What effect will the commands have when entered on R2?
The cisco1 file will be copied to NVRAM.
The commands will not work because a password has not been set on the TFTP server.
The running configuration will be copied from R2 to the TFTP server.
*The cisco1 file will be copied from the TFTP server to the running configuration of R2.

What is the primary function of the NOC at a large ISP?
installing equipment at a customer site
setting up customer accounts and passwords
*monitoring and testing customer network connections
entering customer requirements in an order-tracking database

What is the maximum unrepeated distance set by industry standards for UTP cable?
10 meters
75 meters
*100 meters
325 meters

Refer to the exhibit. A network administrator has an extra router and wishes to use it as shown to passively monitor network traffic. Which IOS feature should be implemented on router EXTRA?
ACLs
CDP
*IDS
IPS

Refer to the exhibit. Hosts that belong to the IT department use 10.10.55.33/27 as a default gateway. Where can this IP address be located in the network?
A
B
C
*D
E

How do Tier 3 ISPs connect to the global Internet?
They connect to the global Internet through Tier 2 ISPs.
They extend across several countries but use the services of a Tier 1 ISP.
They use the services of both Tier 1 and Tier 2 ISPs in order to connect to the global Internet.
*They make up the global backbone of the Internet by physically joining their network with other Tier 3 ISPs.

What is a characteristic of a scalable network?
100% uptime
redundant links
*easy expansion
multiple backup devices

A Cisco switch is installed into a network and two module slots are purposefully left empty. Which network design consideration does this address?
reliability
*scalability
redundancy
accessibility

A company functions from Monday to Friday each week. Their backup strategy calls for full backups each Friday night, with differential backups on all other weekday nights. If an administrator is asked to restore a server hard drive to its Wednesday morning state, how many backups must be used?
1
*2
3
4

Refer to the exhibit. What could be two possible causes for the Serial0/0/0 interface status? (Choose two.)
A Layer 3 issue exists.
The bandwidth is set too high.
*An incorrect cable is being used.
A loopback address must be set.
The reliability setting is too low for the interface.
*A defective serial interface cable was used.

A network designer must specify cable for a 190 meter (625 foot) backbone link where EMI may be an issue. What type of cable should the designer choose?
coaxial
*fiber-optic
shielded twisted pair
unshielded twisted pair

Refer to the exhibit. When the IOS image of a router must be backed up, what are three reasons to issue the exhibited commands? (Choose three.)
to confirm that the IOS image was copied completely
to determine the number of hops to the TFTP server
*to copy the IOS image file to the TFTP server
to set the destination directory on the TFTP server
*to confirm connectivity to the TFTP server
*to view the IOS image name and file size
to confirm that flash has enough space to store the IOS image file

When would TFTP in ROM monitor mode be used to restore a Cisco IOS image to a router?
when a console connection is the only available connection to the router
when the TFTP server software is incompatible with the router IOS version
*when the router is set to boot from flash, but the Cisco IOS image in flash is corrupt or has been erased
when the current Cisco IOS on the router requires a feature upgrade

What will a router do with a packet that is destined for a host with the IP address 192.168.1.5/24 if no entry for the 192.168.1.0/24 network exists in the routing table?
*It will drop the packet.
It will send the packet back to the source address.
It will broadcast the packet out all of its active interfaces.
It will broadcast the packet out all of its active interfaces except the interface that received the packet.

If the NVRAM on a router were to fail, which router resource would be lost?
IOS software image
ROMmon software
running configuration
*startup configuration

In designing a cabling upgrade plan, what is the first best practice that should be implemented?
Suggest the location of the MDF and IDF.
Choose the appropriate wiring.
Choose the new equipment to purchase.
*Examine the floor plan and the condition of existing wiring.
Decide upon the cable management system.

How many host addresses may be assigned on each subnetwork when using the 130.68.0.0 network address with a subnet mask of 255.255.248.0?
30
256
*2046
2048
4094
4096

Which type of address is 192.168.17.111/28?
host address
network address
*broadcast address
multicast address

A customer reports connectivity problems to an ISP technician. Upon questioning the customer, the technician discovers that all network applications are functioning except for FTP. What should the technician suspect is the problem?
*misconfigured firewall
bad port on switch or hub
misconfigured IP addressing on the customer's workstation
wrong DNS server configured on the customer's workstation
wrong default gateway configured on the customer's workstation

A customer reports connectivity problems to an ISP technician. Upon questioning the customer, the technician discovers that all network applications are functioning except for FTP. What should the technician suspect is the problem?
misconfigured firewall
bad port on switch or hub
*misconfigured IP addressing on the customer's workstation
wrong DNS server configured on the customer's workstation
wrong default gateway configured on the customer's workstation

How do port filtering and access lists help provide network security?
*They prevent specified types of traffic from reaching specified network destinations.
They alert network administrators to various type of denial of service attacks as they occur.
They prevent viruses, worms, and Trojans from infecting host computers and servers.
They enable encryption and authentication of confidential data communications.

A hacker attempts to reach confidential information that is stored on a server inside the corporate network. A network security solution inspects the entire packet, determines that it is a threat, and blocks the packet from entering the inside network. Which security measure protected the network?
an IDS
*an IPS
a host-based firewall
Anti-X software

When customers use credit cards to make purchases at a small business, a modem is heard dialing a telephone number to transfer the transaction data to the central office. What type of WAN serial connection is in use?
leased line
packet switched
*circuit switched
point-to-point

The command copy tftp running-config has been entered on the router. What will this command do?
copy the configuration in RAM to a server
*copy the configuration file from a server to RAM
copy the configuration file in NVRAM to RAM
copy the configuration file in NVRAM to a server
copy the configuration file from a server to NVRAM

A network technician is using a network management station to gather data about the performance of devices and links within the ISP. Which application layer protocol makes this possible?
*SNMP
FTP
DHCP
SMTP

A user reports being unable to access the Internet. The help desk technician employs a bottom-up approach to troubleshooting. The technician first has the user check the patch cable connection from the PC to the wall, and then has the user verify that the NIC has a green link light. What will the technician have the user do next?
Enter an IP address into the WWW browser address bar to see if DNS is at fault.
Use traceroute to identify the device along the path to the ISP that may be at fault.
*Verify the IP address, subnet, and gateway settings using ipconfig on the PC.
Connect to the user home router to check firewall settings for blocked TCP ports.

Refer to the exhibit. Which two IP addresses could be assigned to the hosts in the diagram? (Choose two.)
192.168.65.31
192.168.65.32
*192.168.65.35
*192.168.65.60
192.168.65.63
192.168.65.64

Refer to the exhibit. Which command would an administrator use to configure the router name?
Router# ip hostname Boise
Router# hostname Boise
Router(config-line)# name Boise
*Router(config)# hostname Boise
Router> ip hostname Boise

What can cause a problem at the data link layer?
a faulty network cable
a firewall that is blocking all HTTP traffic
*incorrectly configured device drivers
incorrectly configured subnet masks

Which cable type is used to interconnect the FastEthernet interfaces of two routers?
straight-through
*crossover
console
rollover

Which statement is true about FTP implementations?
The protocol interpreter (PI) function engages once the data transfer process (DTP) function is complete.
The DTP function is responsible for the login sequence.
*FTP requires two connections, one for control and one for data.
Both the PI and the DTP close automatically when the transfer is complete.


Which statement is true about the reverse lookup DNS zone?
It is most commonly experienced when users are surfing the Internet.
It is the backup for the forward lookup zone.
It dynamically updates the resource records.
*It resolves an IP address to a fully qualified domain name.

A network is spread across two buildings that are separated by a distance of 500 feet (152 meters). An electrical transformer is installed near the cable route. Which type of cable should be used in this network?
STP
UTP
coaxial
*fiber-optic

Refer to the exhibit. R1 and R2 are configured with the commands that are displayed. All interfaces are properly configured, but neither router is receiving routing updates. What two things can be done to solve the problem? (Choose two.)
*Configure the routing protocol on R1 for network 10.0.0.0.
*Configure the routing protocol on R2 for network 10.0.0.0.
Configure the routing protocol on R1 for network 192.168.4.0.
Configure the routing protocol on R1 for network 192.168.2.0.
Configure the routing protocol on R2 for network 192.168.1.0.
Configure the routing protocol on R2 for network 192.168.3.0.

When a router learns two paths to the same destination network, which two factors determine the path that will be included in the routing table? (Choose two.)
*route metric
the MAC address of the neighboring router
the source IP address in data packets
the IP address of the next hop router
*administrative distance

Which two services are required to enable a computer to receive dynamic IP addresses and access the Internet using domain names? (Choose two.)
*DNS
WINS
HTTP
*DHCP
SMTP

A building has experienced a power outage. When the power returns, none of the devices on one floor can access the Internet. The network administrator checks the switch in the IDF that these devices are connected to and notes that the SYST LED on the front of the switch is amber.
What is a possible cause of this problem?
The switch is functioning properly.
*The switch has failed POST.
The switch configuration file was not saved to NVRAM.
The connection between the switch and the server did not autonegotiate speed and duplex properly.

Refer to the exhibit. While configuring the serial interface of a router, the network administrator sees the highlighted error message. What is the reason for this?
The serial interface is administratively down.
The serial interface is already configured with an IP address.
*The network administrator has attempted to configure the serial interface with a broadcast address.
The same IP address has been configured on another interface.

How does an SNMP trap aid network monitoring and management?
It reports to the management station by responding to polls.
It collects information for the management station by using polling devices.
*It sends an alert message to the management station when a threshold is reached.
It flags attempts to begin a DoS attack on the network.

An organization has 50 traveling salespersons who must be able to connect to the company network from client sites and hotels. Which WAN connection will allow this access?
Frame Relay
Cable
DSL
*dialup

When using NAT on a router, what is the term for the IP address of an inside host as it appears to the outside network?
inside local
*inside global
outside local
outside global

For the assignment of permissions to files and folders, what does the "principle of least privilege" imply?
No user has more privileges than any other user.
Permissions to files are given based on seniority.
*Users only have access to resources that are necessary for their jobs.
Users should be given no access to computer resources until they ask.

A client complains to an ISP that the hosted web server seems slow and frequently cannot be reached. The technician suspects the special high performance server NIC might be the source of the problem. After checking with vendor support, it is verified that the NIC is causing framing errors and the firmware needs to be upgraded. With which layer of the OSI model is this problem associated?
Layer 1
*Layer 2
Layer 4
Layer 7

Which question provides troubleshooting information about a problem at Layer 1 or Layer 2 of the OSI model?
Can the server be reached through Telnet?
Is there a firewall that is configured on the PC?
*Is there a link light on the network card?
What addresses are configured in the TCP/IP settings?

Which protocol allows secure in-band management so that a network administrator can monitor and configure network devices without fear of any passwords being compromised?
*SSH
HTTP
SNMP
Telnet

Refer to the exhibit. Static routes have been configured on all routers in the network. PC2 can communicate with PC1 but not with PC3. What should be done to remedy the problem?
Reconfigure the first static route with the exit interface S0/0/0.
*Reconfigure the second static route with the exit interface S0/0/1.
Reconfigure the first static route with the next hop address 172.16.3.1.
Reconfigure the second static route with the next hop address 172.16.3.1.

Refer to the exhibit. R1 and R2 are connected over a WAN. PC A is connected to the fa0/0 port on R1 and PC B is connected to the fa0/5 port on SW1. Starting with PC A and ending with PC B, what cable types would be used to connect all the devices?
Link A - straight-through, Link B - crossover, Link C - serial, Link D - straight-through.
*Link A - crossover, Link B - serial, Link C - straight-through, Link D - straight-through.
Link A - straight-through, Link B - serial, Link C - crossover, Link D - straight-through.
Link A - crossover, Link B - crossover, Link C- serial, Link D - straight-through.

Refer to the exhibit. Which type of link is supported by this interface module?
LAN
*WAN
WLAN
VLAN

A network technician wants to restore a backup copy of the saved configuration file on a router from a TFTP server. After restoring the file from the TFTP server, the technician reloads the router and finds that it still has the old configuration file instead of the restored file. What could have caused this?
The technician entered the command delete flash: before reloading the router.
The technician entered the command boot system rom before reloading the router.
The technician entered the command erase startup-config before reloading the router.
*The technician failed to enter the command copy running-config startup-config before reloading the router.

Refer to the exhibit. The Transfer > Capture Text feature available through HyperTerminal has been used to capture the running configuration on a router. The startup-configuration has been erased from the router followed by the issuing of the reload command. The startup-config is restored by using the captured file, but all interfaces on the router are shown as administratively down. What could cause this problem?
The enable password was incorrectly entered.
The configuration register was not set to 0x2142.
The enable secret password was incorrectly entered.
*The no shutdown command must be entered under each interface section in the file being sent.
The captured file should have restored the running configuration not the startup configuration.

A network technician wants to load a configuration file from a TFTP server to a router. What must the technician know before initiating the transfer?
*the IP address of the TFTP server and the name of the configuration file on the server
the operating system of the TFTP server and the IP address of the connected router interface
the IP address of the TFTP server and the name of the configuration file in NVRAM of the router
the name of the configuration file on the router and the IP address of the interface that is connected to the TFTP server

At which layer of the OSI model is the Ethernet family of technologies defined?
Layer 1
*Layer 2
Layer 3
Layer 4
Layer 5
Layer 6
Layer 7

Which transport layer protocol will allow segments to be exchanged between two hosts with low overhead and no mechanism for retransmission?
IP
FTP
TCP
*UDP
SMTP

What does the command RA(dhcp-config)# dns-server 10.10.64.221 10.10.64.222 accomplish?
allows RA to act as a DNS relay agent
allows RA to be configured as a DNS server
identifies the default gateway address that is used to reach the DNS servers
*enables DHCP clients to use the specified IP addresses as DNS servers

Which statement best describes HDLC encapsulation?
*It is a bit-oriented data link layer protocol.
It is a circuit-switched network layer protocol.
It is a packet-switched network layer protocol.
It is a packet-switched data link layer protocol.

Which type of WAN connection uses packet-switched connections?
T1
E1
ISDN
*Frame Relay

Which storage media type is most commonly selected if cost effectiveness, large capacity, and transportability are the key factors being considered during implementation of a backup scheme?
*digital tape
solid-state storage
optical media discs
storage area networks
network-attached storage

In a structured cable system, what is the purpose of horizontal cabling?
It connects an IDF to an IDF.
It connects an IDF to the MDF.
*It connects wall jacks to an IDF.
It connects wall jacks to user workstations.

A network engineer has been asked to design a new structured cable system. What should be the first step in the project?
*Obtain an accurate floor plan.
Identify all potential sources of EMI.
Sketch the proposed network design.
Determine the locations of all network devices.

Refer to the exhibit. A network technician is configuring the WAN interface on the HQ router. Which set of commands correctly configures the WAN interface if the IP address that is assigned to the WAN link is 198.133.219.13/30 and router HQ is a DTE device?
HQ(config-if)# ip address 198.133.219.13 255.255.255.248
HQ(config-if)# clock rate 64000
HQ(config-if)# no shutdown
HQ(config-if)# ip address 198.133.219.13 255.255.255.252
HQ(config-if)# clock rate 64000
HQ(config-if)# no shutdown
HQ(config-if)# ip address 198.133.219.13 255.255.255.248
HQ(config-if)# no shutdown
*HQ(config-if)# ip address 198.133.219.13 255.255.255.252
HQ(config-if)# no shutdown

What is a function of an IPS?
It analyzes only layer 7 of the OSI model to identify malicious activity.
It provides perimeter security for the entire network.
It routes traffic to a DMZ or protected internal network.
*It blocks suspicious network activity in real time.
It passively monitors all network traffic that enters the internal network and DMZ.


What is the purpose of the routing process?
to encapsulate data that is used to communicate across a network
*to select the paths that are used to direct traffic to destination networks
to convert a URL name into an IP address
to provide secure Internet file transfer
to forward traffic on the basis of MAC addresses

A network engineer is asked to specify the type of cable for a new network installation. The engineer plans horizontal cable runs of less than 90 feet (27.4 meters) using cable that is not expensive and is easy to implement. It will be positioned away from electrically noisy areas to avoid EMI. Which cable should the engineer choose?
STP
*UTP
coaxial
fiber optic

Which two terms are used to refer to cable connections that run between network distribution facilities? (Choose two.)
patch
*vertical
*backbone
horizontal
crossover

Refer to the exhibit. A user who is connected to RTA is trying to telnet to RTB, but the connection is failing. Based on the output of the show running-config command on router RTB, why is the Telnet session failing?
Telnet has not been configured on the console line.
The login command has not been issued on the console line.
*No password has been configured on the VTY lines.
A session limit has not been configured for Telnet.