It-essentials v7.0 Chapter 6 Exam Answers
1. Users in a recently installed wireless network are complaining of slow data transfer and frequent loss of connectivity. The technician checks that the wireless security is correctly implemented, and there is no evidence of unauthorized users on the network. Which two problems might the technician suspect? (Choose two.)
There is interference from outside sources.*
The DHCP server is faulty.
The wireless signal is too weak.*
The antenna on the access point is too powerful.
The network passwords need to be reissued to the users.
Explanation: Normally, the closer a wireless NIC is to an access point, the faster the connectivity. This problem does not require the network password to be reissued. The combination of the low bandwidth and the intermittent connectivity is pointing towards a weak signal or interference from outside sources.
2. A wired network is undergoing several changes that could leave it vulnerable to connection by unauthorized devices while the work is in progress. Which two temporary measures would enable the authorized devices to continue to have network access but prevent unauthorized devices from connecting? (Choose two.)
Disable DNS.
Disable SSID broadcast.
Disable DHCP.*
Subnet the network.
Assign static IP addresses to the authorized devices.*
Explanation: Disabling DHCP and assigning static IP addresses only to authorized devices will prevent unauthorized devices from automatically obtaining IP address information. Without the correct IP address information, the unauthorized devices will not be able to communicate over the network. Disabling DNS will result in all connected devices no longer automatically being able to communicate with network resources by name (IP addresses would have to be used.), but will not prevent unauthorized devices from connecting and enabling potentially malicious access from occurring. Subnetting the network will change the range of IP addresses used but not prevent unauthorized network access. Disabling SSID broadcasts is only applicable to wireless networks, not wired networks.
3. What two default wireless router settings can affect network security? (Choose two.)
It-essentials v7 Chapter 6 Exam Answers q3
The SSID is broadcast.*
MAC address filtering is enabled.
WEP encryption is enabled.
The wireless channel is automatically selected.
A well-known administrator password is set.*
Explanation: Default settings on wireless routers often include broadcasting the SSID and using a well-known administrative password. Both of these pose a security risk to wireless networks. WEP encryption and MAC address filtering are not set by default. The automatic selection of the wireless channel poses no security risks.
4. A network technician is checking a computer to see if the DHCP client is working correctly. The technician issues the ipconfig /all command. Which two parameters should the technician review? (Choose two.)
description
default gateway*
host name
media state
subnet mask *
Explanation: A DHCP server can provide several parameters such as IP address, subnet mask, default gateway, and other optional parameters. The host name, media state, and description are present even if a DHCP server is not found.
5. A technician is troubleshooting a problem where the user claims access to the Internet is not working, but there was access to the Internet the day before. Upon investigation, the technician determines that the user cannot access the network printer in the office either. The network printer is on the same network as the computer. The computer has 169.254.100.88 assigned as an IP address. What is the most likely problem?
The computer cannot communicate with a DHCP server.*
The IP default gateway on the computer is incorrect.
The network interface card driver needs to be updated.
The router that connects this network to other networks is down.
Explanation: In a network employing dynamic IP addressing, if a computer cannot communicate with the DHCP server to obtain an IP address, the Windows operating system automatically assigns a link-local IP, which is in the range of 169.254.0.0 to 169.254.255.255. In this case, the computer can only communicate with computers connected to the same network within this IP address range.
6. A user can print to a printer that is on the same network, but the traffic of the user cannot reach the Internet. What is a possible cause of the problem?
The PC default gateway address is missing or incorrect.*
The PC has an incorrect IP address.
The network cable connected to the user PC is faulty.
The NIC on the PC is faulty.
Explanation: The default gateway IP address is used to reach other networks, including the Internet.
7. Port triggering has been configured on a wireless router. Port 25 has been defined as the trigger port and port 113 as an open port. What effect does this have on network traffic?
Any traffic that comes into port 25 allows outgoing port 113 to be used.
All traffic that is sent into port 25 to the internal network will also be allowed to use port 113.
Any traffic that is using port 25 going out of the internal network will also be allowed to transmit out port 113.
All traffic that is sent out port 25 will open port 113 to allow inbound traffic into the internal network through port 113.*
Explanation: Port triggering is used to allow inbound traffic through the firewall based on outbound traffic. The trigger occurs when an application makes use of a specific port on the internal network. An external port on the firewall is then opened. This allows for temporary passage of traffic through inbound ports to a specific device.
8. A PC is not able to connect to a wired network. Pinging the loopback address is successful, but the gateway cannot be reached. On the network switch all the interface lights are on, except for the interface connected to the PC. The LED on the network card is off. What is the most likely cause of this problem?
The gateway needs to be fixed.
The network cable is faulty.*
The network switch is faulty.
The PC has an incorrect IP address for the DNS server.
Explanation: The network card is working if the loopback address can be pinged. The LED on the network card being off points towards a faulty cable or a bad connection.
9. The current IP configuration of a small company is done manually and is time-consuming. Because of increased network growth, a technician needs a simpler way for IP configuration of workstations. Which service would simplify the workstation IP configuration task?
APIPA
DHCP*
DIPS
ICMP
Explanation: In networks with more than a few hosts, DHCP simplifies the addressing process. A DHCP server automatically assigns host IP addresses.
10. A technician troubleshooting a network problem has used CLI commands to determine that a computer has not been allocated a correct IP address from the DHCP server. Which command can the technician use to solve this problem?
ping
ipconfig/release
tracert
ipconfig/renew*
Explanation: The command ipconfig/renew will cause the computer to request a new IP address from the DHCP server. The command ipconfig/release will remove the current IP address but will not request a new address. The commands ping and tracert are used to test network connectivity.
11. Which network protocol is used to automatically assign an IP address to a computer on a network?
FTP
DHCP*
ICMP
SMTP
APIPA
Explanation: A Dynamic Host Configuration Protocol (DHCP) server automatically assigns IP addresses, simplifying the addressing process. FTP manages file transfers. SMTP sends email. ICMP is a messaging protocol that is used in troubleshooting. APIPA is Automatic Private IP Addressing, a Windows operating feature that allows DHCP clients to obtain addresses even when a DHCP server is not present.
12. What security technique could provide secure access to a server located in a small office without the expense of implementing a DMZ or purchasing a hardware firewall?
implement hash encoding for all wireless devices
implement MAC address filtering
implement port forwarding*
implement basic security on all wireless access points
Explanation: Port forwarding provides a rule-based method to direct traffic between devices on separate networks. This method provides access to devices across the Internet in a less expensive way than using a DMZ.
13. A group of users is unable to connect to the network. When testing several of the PCs and issuing the command ipconfig, the technician notices that all of them have an IP address in the 169.254.x.x range. What is the most likely cause of this problem?
The Internet connection is down.
The DHCP server is not operational.*
The gateway address is incorrect.
The DNS server is not operational.
Explanation: If the PCs are not able to connect to a DHCP, they will be allocated an IP address within the range 169.254.0.0 – 169.254.255.255.
14. What is the correct compressed format of the IPv6 address 2001:0db8:eeff:000a:0000:0000:0000:0001?
2001:db8:eeff:a::1*
2001:db8:eeff:a:1
2001:db8:eeff:a::0001
2001:db8:eeff:a:::1
Explanation: There are two rules for IPv6 address compression. Rule 1: leading zeros in any hextet can be removed. Rule 2: contiguous hextets of all zeros can be compressed to a double colon. Rule two can only be applied once.
15. What is the proper CIDR prefix notation for a subnet mask of 255.0.0.0?
/8*
/16
/24
/32
Explanation: The proper CIDR notation for a subnet mask of 255.0.0.0 is /8. This is because the /8 indicates that the first eight bits of the subnet mask are set to binary 1.
16. A technician is configuring the channel on a wireless router to either 1, 6, or 11. What is the purpose of adjusting the channel?
to disable broadcasting of the SSID
to enable different 802.11 standards
to provide stronger security modes
to avoid interference from nearby wireless devices*
Explanation: Channels 1, 6, and 11 are selected because they are 5 channels apart. thus minimizing the interference with adjacent channels. A channel frequency can interfere with channels on either side of the main frequency. All wireless devices need to be used on nonadjacent channels.
17. Which network server is malfunctioning if a user can ping the IP address of a web server but cannot ping the web server host name?
the DNS server*
the DHCP server
the FTP server
the HTTP server
Explanation: If pings are successful to an IP address but not to a host name, then the problem may be that a DNS server cannot be accessed.
18. Multiple users report that the workstations are assigned a 169.254.x.x IP address. The users are able to communicate only between each other. What is a possible solution?
Restart the DNS server.
Statically configure a default gateway on each workstation.
Verify the network cable on all user machines.
Restart the DHCP server.*
Explanation: When a network device automatically obtains the IP address 169.254.x.x, it is unable to receive an IP address from a DHCP server. The DHCP server should be restarted to ensure that it is operational.
19. An administrator deploys wireless access points across the office to provide wireless network connectivity to users. Each workstation receives an IP address via DHCP. After a file server with a static IP is connected to the wired network, the administrator receives an IP address conflict message. What is a possible solution?
Restart the DHCP server.
Change the IP address of the file server with the ipconfig /release and ipconfig /renew commands.
Change the static IP configured on the file server.*
Connect the file server to the wireless network.
Explanation: If an IP address conflict message is displayed, then a single IP address is being used more than once on the same network. To solve this issue, the administrator needs to give a different static IP address to the server on the network.
20. A workstation has been moved from the first floor to the fifth floor within an organization. The user is now reporting that the workstation cannot connect to the network. A technician suspects that the workstation could not obtain an IP address from a DHCP server. What is a possible cause of the problem?
An IP address conflict occurred.
The DHCP server is misconfigured.
The workstation has been configured with a static IP address.*
The default gateway address is misconfigured on the workstation.
Explanation: In most cases in an organization, when a computer is moved from one department to another, it needs a new IP address to connect to the network. When a computer is configured with a static IP address, it will not initiate the process of obtaining a new IP address from DHCP servers.
21. A device has been assigned the IPv6 address of 2001:0db8:cafe:4500:1000:00d8:0058:00ab/64. Which is the host identifier of the device?
2001:0db8:cafe:4500:1000:00d8:0058:00ab
2001:0db8:cafe:4500
1000:00d8:0058:00ab*
00ab
Explanation: The address has a prefix length of /64. Thus the first 64 bits represent the network portion, whereas the last 64 bits represent the host portion of the IPv6 address.
22. Which IPv6 address represents the most compressed form of the IPv6 address 2001:0db8:cafe:0000:0835:0000:0000:0aa0/80?
2001:0db8:cafe:0000:0835::0aa0/80
2001:db8:cafe:0000:0835::aa0/80
2001:0db8:cafe:0000:0835::0aa/80
2001:db8:cafe::0835::aa0/80
2001:db8:cafe:0:835::aa0/80*
Explanation: There are two rules that exist to help in the reduction of the number of digits within an IPv6 address: Rule 1 is used to remove any leading 0s. After applying rule 1 to 2001:0db8:cafe:0000:0835:0000:0000:0aa0/80, we calculate the outcome as 2001:db8:cafe:0:835:0:0:aa0/80. Rule 2 is used to replace any group of consecutive zeros once throughout the IPv6 address. After applying rule 2 to 2001:db8:cafe:0:835:0:0:aa0/80, we calculate the outcome as 2001:db8:cafe:0:835::aa0/80.
23. After having talked to the customer, a network technician suspects that an invalid IP address is the most likely cause of a network issue. Which step of the troubleshooting process does this represent?
Identify the problem.
Test the theory to determine the cause.
Establish a theory of probable cause.*
Establish a plan of action to resolve the problem and implement the solution.
Explanation: Before a solution can be proposed or tested, the technician has to first talk to the customer to identify the problem, and establish a theory of probable cause.
24. Which filtering method uses the physical address to specify exactly which device is allowed or blocked from sending data on a network?
MAC address filtering*
port forwarding
port triggering
whitelisting
Explanation: MAC address filtering specifies exactly which device MAC addresses are allowed to or blocked from sending data on your network.
25. How many bits are used to represent an IPv6 address?
128*
48
32
12
26. How many bits are used to represent the host address of a computer with the IP address of 192.168.1.25 and a subnet mask of 255.255.255.0?
8*
48
32
12
27. How many bits are used to represent the network address of a host with an IP address of 192.168.150.16 and a subnet mask of 255.255.0.0?
16*
128
32
4
28. How many bits are used to represent the OUI part of the MAC address of a NIC card?
24*
8
128
42
29. How many bits are used to represent a MAC address?
48*
8
128
64
