Comptia networking questions & Answers.pdf

Chapter 2 34 1. 2. 3. 4. 5. 6. ■ Networking You are installing a fiber-­optic cable between two buildings. To install the cable, you must run it through a conduit between the buildings, and access to the conduit is not easy. Before you run the cable, you want to ensure that it’s working pr...

Chapter 2 34 1. 2. 3. 4. 5. 6. ■ Networking You are installing a fiber-­optic cable between two buildings. To install the cable, you must run it through a conduit between the buildings, and access to the conduit is not easy. Before you run the cable, you want to ensure that it’s working properly. Which tool should you use? A. Cable tester B. Multimeter C. Loopback plug D. Tone generator and probe Which TCP/IP protocol, designed to download email, allows for multiple clients to be simultaneously connected to the same mailbox? A. SMTP B. POP3 C. IMAP D. SMB You are using your laptop on the company network. In your web browser, you type www.google.com and press Enter. The computer will not find Google. You open the browser on your phone, and using your cellular connection, you can open Google without a problem. Your laptop finds internal servers and can print without any issues. What is the most likely reason you can’t open Google? A. DNS server problem B. DHCP server problem C. Missing subnet mask D. Duplicate IP address Which one of the following TCP/IP protocols was designed as a replacement for Telnet? A. SMB B. SSH C. SFTP D. FTPS Which of the following network connectivity devices operates at Layer 2 of the OSI model? A. Hub B. Switch C. Cable D. Router Which of the following TCP/IP protocols is connection-oriented and attempts to guarantee packet delivery? A. IP B. TCP C. UDP D. ICMP Chapter 2 7. 8. 9. ■ Networking 35 Which TCP/IP protocol allows a user to log into a remote computer and manage files as if they were logged in locally? A. FTP B. SFTP C. SMB D. RDP Which Wi-­Fi standard is the fastest, operating in both the 2.4 and 5 GHz frequencies? A. 802.11a B. 802.11ac C. 802.11ax D. 802.11n Bob has a device that operates at 5 GHz. He is unable to connect his device to a LAN that he hasn’t accessed before, although he has verified that he has the correct password. What type of network might pose this problem? A. 802.11g B. 802.11n C. 802.11ac D. 802.11ax 10. Which TCP/IP protocol is used to provide shared access to files and printers on the network? A. FTP B. SSH C. SMB D. SMTP 11. What port does the Telnet protocol use? A. 21 B. 22 C. 23 D. 25 12. You have just installed a wireless 802.11ac network for a client. The IT manager is concerned about competitors intercepting the wireless signal from outside the building. Which tool is designed to test how far your wireless signal travels? A. Tone generator and probe B. Protocol analyzer C. Packet sniffer D. Wi-­Fi analyzer Chapter 2 36 ■ Networking 13. Some of your network users are concerned about submitting confidential information to an online website. What should you tell them? A. It’s fine, because all Internet traffic is encrypted. B. If the website address starts with TLS://, it should be OK to submit confidential information to a trusted site. C. If the website address starts with HTTPS://, it should be OK to submit confidential information to a trusted site. D. Don’t ever submit confidential information to any online website. 14. Which TCP/IP Internet layer protocol is responsible for delivering error messages if communication between two computers fails? A. ICMP B. IP C. TCP D. UDP 15. Which type of IPv6 address identifies a single node on the network? A. Multicast B. Anycast C. Unicast D. Localcast 16. What type of network covers large geographical areas and often supports thousands of users, often using lines owned by other entities? A. LAN B. WAN C. PAN D. MAN 17. Which TCP/IP protocol, developed by Microsoft, uses port 3389 to connect to a remote computer? A. RDP B. SMB C. CIFS D. Telnet 18. What port does the SSH protocol use? A. 21 B. 22 C. 23 D. 25 Chapter 2 ■ Networking 37 19. Which of the following IP addresses is not routable on the Internet? A. 10.1.1.1 B. 11.1.1.1 C. 12.1.1.1 D. 13.1.1.1 20. Which network connectivity device does not forward broadcast messages, thereby creating multiple broadcast domains? A. Hub B. Switch C. Bridge D. Router 21. What type of address does a router use to get data to its destination? A. IP B. MAC C. Memory D. Loopback 22. You have a desktop computer that is behaving erratically on the network. The wired connection will often disconnect without warning. Which tool should you use to troubleshoot the network adapter? A. Multimeter B. Tone generator and probe C. Loopback plug D. Cable tester 23. Your company just expanded and is leasing additional space in an adjacent office building. You need to extend the network to the new building. Fortunately, there is a conduit between the two. You estimate that the cable you need to run will be about 300 meters long. What type of cable should you use? A. CAT-­5e B. CAT-­7 C. CAT-­8 D. MMF 24. You want to ensure that client computers can download email from external email servers regardless of the protocol their email client uses. Which ports do you open on the firewall to enable this? (Choose two.) A. 23 B. 25 C. 110 D. 143 Chapter 2 38 ■ Networking 25. You are installing network cabling in a highly secure facility. The cables need to be immune to electronic eavesdropping. What type of cable should you use? A. Fiber-­optic B. UTP C. STP D. Coaxial 26. Which networking device is capable of reading IP addresses and forwarding packets based on the destination IP address? A. Hub B. Switch C. NIC D. Router 27. Which network device is designed to be a security guard, blocking malicious data from entering your network? A. PoE injector B. EoP device C. Firewall D. Router 28. You are manually configuring TCP/IP hosts on the network. What configuration parameter specifies the internal address of the router that enables Internet access? A. Subnet mask B. DHCP server C. DNS server D. Default gateway 29. Which of the following devices will be found in a telecommunications room and provides a means to congregate horizontal wiring, terminating each run in a female port? A. Patch panel B. Multiplexer C. Rack U D. Demarcation point 30. What type of network is most commonly associated with Bluetooth devices such as wireless keyboards, mice, and headphones, and covers a small area? A. LAN B. WAN C. PAN D. MAN Chapter 2 ■ Networking 39 31. When troubleshooting a network connectivity issue, you discover that the local computer has an IPv4 address of 169.254.2.2. What do you immediately know about this local computer? A. It is working fine. B. It can’t find a DHCP server. C. It isn’t on the network. D. It has an invalid IP address. 32. Which of the following IPv6 addresses is automatically assigned by the host when it boots and is only usable on the broadcast domain that it exists in? A. 2000::/3 B. FC00::/7 C. FE80::/10 D. FF00::/8 33. You need to configure a wireless router for an office network. The office manager wants new devices to be able to automatically join the network and announce their presence to other networked devices. Which service should you enable to allow this? A. DHCP B. NAT C. QoS D. UPnP 34. You are troubleshooting a computer with an IPv6 address that is in the FE80::/10 range. Which of the following statements are true? (Choose two.) A. The computer will not be able to get on the Internet using that IP address. B. The computer will be able to get on the Internet using that IP address. C. The computer is configured with a link-­local unicast address. D. The computer is configured with a global unicast address. 35. You have set up your web server to function as an FTP server as well. Users on the Internet complain that they are not able to access the server using FTP clients. What port should they be trying to access the server on? A. 21 B. 22 C. 23 D. 80 36. Which TCP/IP protocol allows you to access data such as employee phone numbers and email addresses that are stored within an information directory? A. SNMP B. SMTP C. CIFS D. LDAP Chapter 2 40 ■ Networking 37. What port is associated with the LDAP protocol? A. 22 B. 139 C. 389 D. 3389 38. You are configuring network hosts with static IP addresses. You have chosen to use a Class B network address. What is the default subnet mask that you should configure on the hosts? A. 255.0.0.0 B. 255.255.0.0 C. 255.255.255.0 D. 255.255.255.255 39. You are installing a new network and working in a telecommunications room. You need to attach several network cables to a 110 block. Which tool should you use to perform this task? A. Crimper B. Cable stripper C. Cable tester D. Punchdown tool 40. Which of the following Internet connection types offers the fastest download speeds? A. Cable B. DSL C. Fiber-­optic D. Satellite 41. Which of the following are public IPv4 addresses? (Choose two.) A. 69.252.80.71 B. 144.160.155.40 C. 172.20.10.11 D. 169.254.1.100 42. Which TCP/IP protocol uses port 445? A. FTP B. SSH C. SMB D. SNMP Chapter 2 ■ Networking 41 43. What rendition of SMB was used by Windows servers and NAS servers but is no longer often used? A. CIFS B. Samba C. NFS D. SMB3 44. For IPv6, which of the following statements are true? (Choose two.) A. Each IPv6 interface can have only one address. B. Each IPv6 interface is required to have a link-­local address. C. IPv6 addresses are incompatible with IPv4 networks. D. IPv6 does not use broadcasts. 45. Which network connectivity device is seldom used in modern networks, except to extend a network? A. Bridge B. Hub C. Switch D. Router 46. There is a TCP/IP protocol that should only be used locally because it has virtually no security. It may be used as a part of a preboot execution environment (PXE) or with thin clients booting from a network drive. It uses very little memory and is good for transferring boot files or configuration data between computers on a LAN, and it is connectionless. Which file transfer protocol is this? A. FTP B. TFTP C. FTPS D. SMTP 47. Which of the following IPv6 addresses is equivalent to 127.0.0.1 in IPv4? A. ::0 B. ::1 C. ::127 D. 2000::/3 48. You are asked to perform consulting work for a medium-­sized company that is having network connectivity issues. When you examine the patch panel, you notice that none of the dozens of UTP cables are labeled. Which tool can you use to identify which cable goes to which workstation? A. Cable tester B. Loopback plug C. Punchdown tool D. Tone generator and probe Chapter 2 42 ■ Networking 49. Which TCP/IP protocol is responsible for dynamically assigning IP addresses to client computers? A. DNS B. DHCP C. RDP D. LDAP 50. Which networking device has multiple ports, each of which is its own collision domain, and examines the header of the incoming packet to determine which port the packet gets sent to? A. Hub B. Switch C. Bridge D. Router 51. Which TCP/IP port will an email client use to push email to its email server? A. 23 B. 25 C. 110 D. 143 52. A technician is going to set up a Wi-­Fi network using standard omnidirectional antennae. Because of the building configuration, transmitting signals for the greatest distance is the technician’s primary criterion. Which standard should they choose? A. 802.11a B. 802.11g C. 802.11n D. 802.11ac 53. You are troubleshooting an intermittently failing Cat 6 network connection. You suspect that there is a short in the connection. Which tool can you use to determine this? A. Tone generator and probe B. Loopback plug C. Cable tester D. Crimper 54. What marks the boundary of a IPv4 broadcast domain? A. Hub B. Switch C. Router D. Modem Chapter 2 ■ Networking 43 55. Which TCP/IP protocol gathers and manages network performance information using devices called agents? A. SNMP B. SMTP C. LDAP D. SMB 56. Which Internet connection type, once popular for home use, offers asymmetrical download and upload speeds and is implemented over common phone lines? A. POTS B. Cable C. DSL D. ISDN 57. You are installing an 802.11n Wi-­Fi network with five wireless access points. The access points are set up so their ranges overlap each other. To avoid communications issues, what principle should you follow when configuring them? A. Configure all access points to use the same channel. B. Configure all access points to use adjacent channels. C. Configure all access points to use nonoverlapping channels. D. Channel configuration will not cause communications issues. 58. You need to configure email settings for use with IMAP. Which port will you be configuring? A. 25 B. 80 C. 110 D. 143 59. Which of the following technologies will enable you to install networking devices that need power to function, in a location that has no power outlets? A. EoP B. PoE C. WAP D. Hub 60. You have been asked to install a Wi-­Fi network in a building that is approximately 100 meters long and 25 meters wide. Because of cost considerations, you will be using 802.11ac. At a minimum, how many wireless access points will you need? A. Two B. Three C. Four D. Six Chapter 2 44 ■ Networking 61. What two tools will you need to connect an RJ45 connector to an appropriate cable? (Choose two.) A. Punchdown tool B. Network tap C. Crimper D. Cable stripper 62. You are installing network cabling in a drop ceiling of an office space. The ceiling area is used to circulate breathable air. What type of cable must you install? A. Coaxial B. UTP C. Fiber-­optic D. Plenum 63. You need to install a wireless access point in a drop ceiling where there is no access to a power source. Which technology will allow you to get power to that device? A. EoP B. PoE C. Hub D. Repeater/extender 64. Which of the following IP addresses is not a private address and therefore is routable on the Internet? A. 10.1.2.3 B. 172.18.31.54 C. 172.168.38.155 D. 192.168.38.155 65. You are configuring a wireless 802.11ax router. The office manager insists that you configure the router such that traffic from her computer receives higher priority on the network than other users’ traffic. Which setting do you need to configure to enable this? A. QoS B. UPnP C. Screened subnet D. Port forwarding 66. If you are connecting to a website that encrypts its connection using TLS, what port does that traffic travel on? A. 21 B. 80 C. 143 D. 443 Chapter 2 ■ Networking 45 67. Your network is currently running a mix of 802.11b and 802.11g devices. At the end of the year, you have extra budget to upgrade some, but not all, of the wireless infrastructure. You want to upgrade to the newest technology possible but still maintain backward compatibility. Which standard should you choose? A. 802.11g B. 802.11ac C. 802.11ax D. 802.11r 68. What type of network spans multiple buildings or offices, possibly even crossing roads, but is confined to a relatively small geographical area? A. LAN B. WAN C. PAN D. MAN 69. Which of the following shorthand notations corresponds to the CIDR subnet mask 255.255.224.0? A. /19 B. /20 C. /21 D. /22 70. You are configuring hosts on a network running IPv4. Which elements are required for the computer to connect to the network? A. IP address B. IP address and subnet mask C. IP address, subnet mask, and default gateway D. IP address, subnet mask, default gateway, and DNS server address 71. You work at a tech support company and a customer called reporting that they received an error, something about a duplicate IP address. Why are they getting this message? (Choose two.) A. All hosts on a network must have a unique IP address. B. A PC is manually configured with an IP that is in the DHCP scope. C. A PC is manually configured with an IP that is not in the DHCP scope. D. None of the PCs have been manually configured. Chapter 2 46 ■ Networking 72. You’re setting up a network for a customer. The network uses a DHCP server, but the customer needs an IP address for their print server that does not change. What are two possible solutions? (Choose two.) A. Let the DHCP server assign a number because once assigned, it will not change. B. Manually configure the print server to have a static IP address. C. Configure a reserved IP address on the DHCP server for the print server. D. Static and dynamic IP addresses can’t exist on the same network. You’ll have to manually configure everything. 73. Which obsolete Wi-­Fi encryption standard uses a static key, which is commonly 10, 26, or 58 characters long? A. WPA3 B. WPA2 C. TKIP D. WEP 74. You’ve been asked to set up a device that will be monitored using an SNMP agent and manager. What port will the SNMP manager use when polling the agent? A. TCP 143 B. UDP 143 C. TCP 161 D. UDP 161 75. Because of a recent security breach, your IT team shut down several ports on the external firewall. Now, users can’t get to websites by using their URLs, but they can get there by using IP addresses. What port(s) does the IT team need to open back up to enable Internet access via URLs? A. 20/21 B. 53 C. 67/68 D. 80 76. All your network hosts are configured to use DHCP. Which IP address would indicate that a host has been unable to locate a DHCP server? A. 192.168.1.1 B. 10.1.1.1 C. 172.16.1.1 D. 169.254.1.1 Chapter 2 ■ Networking 47 77. You have reason to believe that several network users are actively browsing prohibited content on unsecured sites on the Internet. Which port can you disable on the firewall to immediately stop access to these websites? A. 53 B. 67 C. 80 D. 443 78. Which TCP/IP protocol is designed to help resolve hostnames to IP addresses? A. ARP B. RARP C. DHCP D. DNS 79. You need to install an Internet connection for a forest ranger outlook tower, located far away from electrical lines. Which option would be best for broadband Internet access? A. Cable B. DSL C. Fiber D. Satellite 80. Your customer will be moving their small office to a remote mountain village where there is no cable Internet access. They have heard that there is a wireless option available in the area that is faster than satellite but that requires an antenna and line-­of-­sight to a tower. What option have they heard about? A. Satellite B. DSL C. WISP D. Cellular hotspot 81. Which TCP/IP host-­to-­host protocol makes its best effort to deliver data but does not guarantee it? A. IP B. TCP C. UDP D. ICMP 82. What type of network is typically defined as being contained within a single office or building? A. LAN B. WAN C. PAN D. MAN Chapter 2 48 ■ Networking 83. You are installing a wireless network for a small company. The management wants to have 1 Gbps or better wireless transmission rates. Which of the following standards will allow you to provide this? (Choose two.) A. 802.11ac B. 802.11ax C. 802.11g D. 802.11n 84. Which of these standards operate in both the 2.4 GHz and 5 GHz frequencies? (Choose two.) A. 802.11ac B. 802.11ax C. 802.11g D. 802.11n 85. What legacy network protocol allows NetBIOS-­dependent computer applications to communicate over TCP/IP? A. TFTP B. HTTPS C. NetBT D. BGP 86. Which of the following features does not require a managed network switch? A. Priority of traffic B. VLAN configuration C. Direct packets out the proper port D. Port mirroring 87. The senior network administrator struggles to configure company network devices spanning several cities. It’s a challenge because they are required to be on premises for the network infrastructure of each building. What would be a cost-­effective solution? A. Employ network administrators at each building. B. Go to a flat network. C. Train a local sales associate. D. Employ a cloud-­based network controller. 88. What port(s) does DHCP use? A. 67/68 B. 137/139 C. 80 D. 445 Chapter 2 ■ Networking 49 89. What is the maximum distance allowed between a power over Ethernet injector and the Ethernet device running on a 1000BaseT network? A. 50 meters B. 100 meters C. 250 meters D. 450 meters 90. Which of the following protocols uses port 137 and 139? A. DNS B. SMB C. NetBT D. SSH 91. When setting up a small office, home office (SOHO) network, how do the end-­user devices know what IP address they need to use to connect with the network? A. The network switch broadcasts configuration settings. B. Devices utilize service location protocol. C. The NIC is set with a static address or DHCP-­served. D. End users configure IP addresses as needed. 92. You’ve been asked to set up a wireless network for a SOHO that will only allow five specific devices to connect. How do you accomplish this? A. Disable the router’s SSID. B. Configure port forwarding. C. Set a DHCP scope with only five addresses. D. Configure MAC address filtering. 93. What is the most likely way for a homeowner’s IoT devices to connect to their wireless network? A. DNS B. AD C. SSO D. DHCP 94. What type of communication technology is being used at a fast-­food restaurant when a customer places their phone next to a device to pay for their purchase? A. RFID B. NFC C. Wi-­Fi D. HAV Chapter 2 50 ■ Networking 95. What communication technology allows for low-­power, passive reading of a small tag or patch on an object that may be a few feet to dozens of feet away? A. RFID B. NFC C. Wi-­Fi D. RFI 96. What type of server provides Internet access to company-­provided information such as how to contact a company, products or services for sale, and other information? A. FTP server B. Proxy server C. File server D. Web server 97. A friend is showing you how they can control their thermostat at home from their cell phone while at work. What type of device do they have at home? A. IoT B. SQL C. DoS D. EFS 98. What server would function as a central repository of documents and provide network shared file storage for internal users? A. FTP server B. Proxy server C. File server D. Web server 99. You work as a network administrator for a school district. The district is required to provide access to the Internet for students but also required to protect the network and the students from malicious network traffic and inappropriate websites. What type of server do you need to configure? A. FTP server B. Proxy server C. File server D. Web server Chapter 2 ■ Networking 51 100. What type of server can host files for easy access and downloading, similar to how a web server serves web pages? A. FTP server B. Proxy server C. File server D. DNS server 101. You’re a network administrator and just added a device to your network that allows multiple users to access several printers. What have you attached to the network? A. Syslog server B. DNS server C. Print server D. Authentication server 102. What server is used to resolve domain names to IP addresses to facilitate web browsing or locating a directory resource on the network? A. Syslog server B. DNS server C. Print server D. Authentication server 103. What server is accessed each time it’s necessary to challenge and validate a user’s credentials in order for the user to access a network resource? A. Syslog server B. DNS server C. Print server D. Authentication server 104. What service can collect and journal all the system-­generated messages produced by servers and network devices? A. Syslog server B. DNS server C. Print server D. Authentication server 105. You’re configuring your phone to download and upload email. What type of server are you configuring your phone to use? A. Web server B. Authentication server C. Mail server D. FTP server Chapter 2 52 ■ Networking 106. Which of the following are connection-­oriented protocols? (Choose two.) A. DHCP B. TFTP C. HTTPS D. SSH 107. A company wanting to monitor network traffic or host system behavior to identify suspect activity will install what type of service? A. Proxy server B. IDS C. UTM D. ATM 108. What is the primary difference between an IDS and an IPS? A. IDS works both on a host and a network. B. IDS will not actively alert on suspect activity. C. IPS works in pairs. D. IPS will actively react to suspect activity. 109. Managing security on your growing network has become difficult, so you ask your peers what they are doing to manage their networks. They recommend a device that will allow you to manage your security in one place. What have they recommended? A. IDS B. IPS C. UTM D. UTP 110. A switch is overheating, and the SNMP agent is sending an SNMP trap to an SNMP manager. Which of the following are true? (Choose two.) A. It is a managed switch. B. It is an unmanaged switch. C. It is communicating on port 161. D. It is communicating on port 162. 111. Your cousin is a nature photographer, traveling the country and living in their Class A motorhome. Much of the time their motorhome is parked in a national park, but seldom is Wi-­Fi available. Your cousin uploads photos from their camera to a laptop, modifies them, and needs to upload them to their publisher, various magazines, and their website on a regular basis. What is a viable networking option for your cousin? A. Satellite B. Cellular C. WISP D. DSL Chapter 2 ■ Networking 112. Based on the drawing, what is the device labeled A? PC Cable Internet Service Provider A. Switch B. Hub C. Cable modem D. Cable multiplexer 113. What is the device in the image used for? A Router PC PC 53 Chapter 2 54 ■ Networking A. It multiplexes several signals into one. B. It’s a network cable tester. C. It’s for attaching RJ45 connectors to cable. D. It’s for testing Wi-­Fi signal strength. 114. You are a network administrator. Currently there is no wireless access to the business network, but the company is purchasing tablets so that employees can take their work with them as they move around the facility. What device will you install so that employees will be able to connect to the wired network with wireless devices? A. Ethernet router B. Proxy server C. WAP D. NFC hub 115. Last weekend you installed and booted several more computers to be ready for Monday morning. Later Monday morning you hear from employees as they come in that they cannot log in. Their desktops don’t seem to want to connect. You investigate and find that each faulty workstation has a 169.254.x.x IP address. What might you look at next? A. DHCP scope B. LAN connector broken C. Windows patch unable to install D. Corrupted Registry 116. What network segmentation technique reduces broadcast domains and provides a layer of security between users on the same network? A. VPN B. VLAN C. UPS D. SQL 117. One of your network users must work remotely from their office on an extremely confidential project. Their team is concerned about security so they call you, the IT department head, to see what can be done. What will you set up between this network user and the company server so that the communications are secure? A. VPN B. SDN C. VLAN D. SRAM 118. Which of the following components is not typically found in a wireless LAN (WLAN)? A. WLAN router B. WLAN gateway C. WLAN server D. WLAN client Chapter 2 ■ Networking 119. You need to configure dynamic IP addressing on your network to cut down on management time. How will you do this? (Choose two.) A. Enable DHCP settings on the router. B. Configure each NIC to obtain an IP address automatically. C. Configure each NIC to a specific IP address. D. Configure each NIC to obtain DNS server addresses automatically. 120. Your network admin needs to add a computer to an IPv6 subnet. Which of the following IPv6 addresses is on the same subnet as 2601:0:0:0f:1a:308c:2acb:fee2? A. 2601::of:308c:47:4321 B. 2601::0f:ab:cd:123:4a C. fe80:ab:bc:0f:1a:308c:2abc:fee5 D. 2601:0:0:0x::2acb:ac01 121. Dylan is troubleshooting his IPv4 network. The network’s subnet mask is 255.255.192.0. Which of the following IP addresses is not on the same network as the others? A. 130.200.65.5 B. 130.200.130.1 C. 130.200.100.4 D. 130.200.125.5 122. Which of the following is a PoE standard? A. 802.3bt B. 802.3b C. 802.11 D. 802.11ax 123. Your friend has purchased a PoE device for their home. It is a type 2 device. Which of the following PoE switches will be compatible with this device? (Choose two,) A. 802.3af-­compliant switch B. 802.3at-­compliant switch C. 802.3bt-­compliant switch D. 802.11b-­compliant switch 124. Which of the following is true of an ONT? (Choose two.) A. It stands for optical network terminator. B. It converts fiber-­optic light signals to electrical (Ethernet) signals. C. It is user installed. D. It requires external power to work properly. 55 Chapter 2 56 ■ Networking 125. Which of the following is not a benefit of software-­defined networking (SDN)? A. Dynamic load balancing B. Reduced infrastructure costs C. Requires a cloud-­based network D. Centrally manage physical and virtual routers 126. Which type of WISP radio frequency has the advantages of no fees, less expensive equipment, and a wide pool of practical knowledge so help is easier to find? A. Licensed B. Unlicensed C. Limited D. Unlimited 127. You are working with your customer, a doctor’s office, to develop a network that will allow the doctor’s staff to work with their tablet PCs in any room of the office without having to worry about network cabling. What type of network will you establish for the doctor’s office? A. LAN B. VLAN C. WLAN D. WAN 128. Which of the following is a network of storage devices that a server can access as if it were a locally connected drive? A. NAS B. SAS C. SAN D. WAN 129. Which of the following is true of a network TAP? (Choose two.) A. TAP stands for terminal access point. B. It is solely used by hackers to intercept packets. C. It is part of a router. D. It allows network admins to monitor network traffic. 130. What software runs on a machine where data files to be accessed are housed and controls access to those files as requested by a client? A. CAL B. Fileshare server C. Fileshare client D. SAN Chapter 2 ■ Networking 57 131. A friend is having some issues with the wireless network in their apartment dropping the connection or running very slowly. What tool can be used to determine the best channel to use? A. WAP B. Wi-­Fi analyzer C. Toner probe D. Cable tester 132. In the United States, the Federal Communications Commission (FCC) imposes rules that govern radio communications. What is the maximum EIRP (watts) that can be transmitted in the 2.4 GHz band for a point-­to-­multipoint WISP connection? A. 2 watts B. 4 watts C. 158 watts D. 125 mw 133. Using which Wi-­Fi channels does not require that your router has Dynamic Frequency Selection (DFS) and Transmit Power Control (TPC) built into the router? A. Channels 36 to 48 B. Channels 52 to 64 C. Channels 100 to 144 D. Channels 149-­165 134. Which broadband network communications technology became more competitive with other types of service when, in 2021, the FCC ruled to include it in the Over-­The-­Air-­ Reception Devices Rule (OTARD), which protects the rights of those organizations to place antennas where they are needed? A. Fios B. Long-­range fixed wireless C. DSL D. Satellite 135. What is the host number in an IP address of 192.168.2.200 and a subnet mask of 255.255.255.0? A. 192.168 B. 192.168.2 C. 2.200 D. 200 Chapter 2 58 ■ Networking 136. What are the three A’s employed by authentication servers? A. Authentication, activation, acceptance B. Authorization, access, allocation C. Accept, access, accounting D. Authentication, authorization, accounting 137. Which Internet appliance is used to distribute incoming traffic over resources, such as multiple web servers? A. Proxy servers B. Spam gateways C. Load balancers D. UTM device 138. What type of system, consisting of both hardware and software, is used to control and monitor industrial machines and processes? A. SCADA B. IrDA C. UTM D. RADIUS 139. Your friend owns a restaurant and provides free Wi-­Fi to their clientele. Lately they have been receiving complaints that the Wi-­Fi isn’t working. It seems to work for customers already connected but not for people trying to connect. What can be configured on the router to release an IP address and make it available for other users after a couple of hours? A. MAC address filtering B. Port forwarding C. DHCP lease duration D. SSID broadcast 140. What type of address is known as a DNS AAAA address? A. IPv4 B. IPv6 C. MAC D. Physical 141. What type of entry in a DNS record can be used for load balancing of incoming mail? A. MX B. DX C. AAAA D. TXT Chapter 2 ■ Networking 59 142. What type of DNS record contains a list of users (IP addresses) that are authorized to send email on behalf of a domain? A. DKIM B. SPF C. DMARC D. A 143. What is the interface ID of the IP address 2001::1a3:f1a:308:833? A. 2001:0:0:0: B. 2001 C. 1a3:f1a:308:833 D. 833 144. What two terms are used to identify an Internet provider that may connect to the Internet using T1 or T3 lines, or fiber optic, for example, and uses point-­to-­point millimeter-­wave or microwave links between its towers for its backbone or to extend its service area, and point-­to-­multipoint wireless to provide Internet access to its customers? A. WISP B. ISP C. Demarcation point D. Long-­range fixed wireless 145. Your friend is again considering the network configuration in their apartment. They’ve asked you the difference between channels on the 2.4 GHz and 5 GHz networks that are available on their Internet connection. What will you tell them? (Choose two.) A. If they are using the 2.4 GHz network, they should choose channel 1, 6, or 11 because they don’t overlap each other. B. The 5 GHz network channels provide greater bandwidth, so data could be transferred faster, but they may have more interference with their neighbors. C. The 5 GHz frequency is considered obsolete, so the 2.4 GHz frequency should be used. D. All of the 5 GHz frequencies overlap, so there will be greater interference. 146. Which IEEE Wi-­Fi standard is also known as Wi-­Fi 6? A. 802.11a B. 802.11ac C. 802.11ax D. 802.11n Chapter 2: Networking 397 ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ Chapter 2: Networking 1. A. Cable testers are indispensable tools for any network technician. Usually you would use a cable tester before you install a cable to make sure it works. Of course, you can test them after they’ve been run as well. Multimeters are used to test power supplies and wall outlets. Loopback plugs are used to test network interface cards, and tone generators and probes are used to locate a wire among other wires. 2. C. Internet Message Access Protocol (IMAP) is a secure protocol designed to download email. It has several advantages over the older Post Office Protocol 3 (POP3). First, IMAP4 works in connected and disconnected modes. Second, it lets you store the email on the server, as opposed to POP3, which requires you to download it. Third, IMAP4 allows 398 Appendix ■ Answers to the Review Questions multiple clients to be simultaneously connected to the same inbox. Simple Mail Transfer Protocol (SMTP) is used for sending mail, and Server Message Block (SMB) is used in sharing files across a network. 3. A. The Domain Name System (DNS) server is responsible for resolving hostnames, such as www.google.com, to IP addresses to enable communication. If it’s not working properly or you can’t connect to it, you won’t be able to browse the Internet using friendly website names. Dynamic Host Configuration Protocol (DHCP) is used to assign IP addresses to network clients. The subnet mask might be incorrect, but it wouldn’t be missing, and a duplicate IP address would provide an error message stating that. 4. B. Secure Shell (SSH) can be used to set up a secure session over port 22 for remote logins or for remotely executing programs and transferring files. Because it’s secure, it was originally designed to be a replacement for the unsecure telnet command. Server Message Block (SMB), File Transfer Protocol (FTP), and FTP Secure (FTPS) protocols are used for sharing files across a network. 5. B. A switch operates at layer 2 of the open systems interconnection (OSI) model. Layers of the OSI model are (1) physical, (2) datalink, (3) network, (4) transport, (5) session, (6) presentation, and (7) application. The physical layer encompasses transmission media such as unshielded twisted pair (UTP), shielded twisted pair (STP), fiber optic, and so on. The datalink layer deals with transmitting frames on a LAN, so it includes the network interface card (NIC) and switch. Routers operate on OSI layer 3, because they transmit data between networks. Hubs work on OSI layer 1 because they merely connect devices in the same collision domain without regard to packet header information. The OSI model is not listed as an objective on the CompTIA A+ exam, but understanding it will help you understand network communications. 6. B. Transmission Control Protocol (TCP) guarantees packet delivery through the use of a virtual circuit and data acknowledgments, and User Datagram Protocol (UDP) does not. Because of this, TCP is often referred to as connection-oriented, whereas UDP is connectionless. Internet Protocol (IP) is used to get packets to their destination across the Internet, and Internet Control Message Protocol (ICMP) is used by connectivity devices to diagnose problems and send messages. 7. D. Remote Desktop Protocol (RDP) is a replacement for the older Telnet protocol, which is not secure. RDP, as its name implies, lets users log into a local machine and use a remote machine almost as if they were sitting at it. RDP uses port 3389. File Transfer Protocol (FTP), Secure File Transfer Protocol (SFTP), also called Secure Shell (SSH) FTP, and Server Message Block (SMB) protocols are all used for sharing files across a network. 8. C. 802.11ax (Wi-­Fi 6) is considered a replacement for 802.11ac (Wi-­Fi 5). 802.11ac operates in the 5 GHz frequency, while 802.11ax can operate between 1 and 7.125 GHz frequencies, encompassing the 2.4 GHz and 5 GHz bands. 802.11ac can send data at over 1 Gbps, while 802.11ax can be several times that. 802.11a was adopted in 1999. It operates at 54 Mbps in the 5 GHz frequency band. 802.11n was adopted in 2008. It operates at 600 Mbps in both the 2.4 GHz and 5 GHz ranges. 9. A. If Bob is trying to connect to an 802.11g network, his device will not be able to connect because 802.11g operates on the 2.4 GHz frequency only. 802.11n and 802.11ax both operate on 2.4 GHz and 5 GHz. 802.11ac operates only on the 5 GHz frequency. Chapter 2: Networking 399 10. C. Server Message Block (SMB) is a protocol used to provide shared access to files, printers, and other network resources. In a way, it functions a bit like File Transfer Protocol (FTP), only with a few more options, such as the ability to connect to printers and more management commands. Secure Shell (SSH) uses encryption to create a secure contact between two computers, and Simple Mail Transfer Protocol (SMTP) is used for sending email. 11. C. Telnet lets users log into another machine and “see” the remote computer in a window on their screen. Although this vision is text only, users can manage files on that remote machine just as if they were logged in locally. Telnet uses port 23. Telnet has been largely replaced by Secure Shell (SSH), and SSH (over port 22) is more secure than Telnet. Port 21 is used by File Transfer Protocol (FTP), and port 25 is used by Simple Mail Transfer Protocol (SMTP). 12. D. A wireless locator, or a Wi-­Fi analyzer, can be either a handheld hardware device or specialized software that is installed on a laptop, smartphone, or other mobile device and whose purpose is to detect and analyze Wi-­Fi signals. It can detect where signals are strong or weak to determine whether there are potential security issues. A tone generator and probe are used for locating a wire. Protocol analyzers and packet sniffers are tools used for capturing and analyzing network traffic. 13. C. Internet traffic is not encrypted by default. Websites that are secure and encrypt their transmissions will start with HTTPS:// rather than HTTP://. These sites can be trusted to encrypt the data, and their identity is verified. 14. A. The main Internet layer protocol is Internet Protocol (IP), and it’s the workhorse of TCP/ IP. Another key protocol at this layer is Internet Control Message Protocol (ICMP), which is responsible for delivering error messages. If you’re familiar with the ping utility, you’ll know that it utilizes ICMP to send and receive packets. Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) are both communication protocols; TCP guarantees delivery but UDP does not. 15. C. There are three types of addresses in IPv6: unicast, anycast, and multicast. A unicast address identifies a single node on the network. An anycast address refers to one that has been assigned to multiple nodes, and a packet will be delivered to one of them. A multicast address is one that identifies multiple hosts, and a packet will be sent to all of them. 16. B. A wide area network (WAN) covers large geographical areas and often supports thousands of users. A WAN can be for different locations of a single company, or a WAN may connect several different companies together to share information. WAN lines are often leased from a WAN provider. The Internet is considered to be a very large WAN. A local area network (LAN) covers a relatively small area such as a home or business. A personal area network (PAN) is usually used by one person and consists of their computer and its Bluetooth devices. A metropolitan area network (MAN) is similar to a WAN, but the area covered is much smaller, such as a university or a city. 17. A. Developed by Microsoft, the Remote Desktop Protocol (RDP) allows users to connect to remote computers and run programs on them as if they were sitting at the computer. It uses port 3389. A port is associated with a specific protocol and must be “opened” on a router to allow traffic from the program or protocol to enter the LAN. The combination of an IP address and a port is considered a socket. The IP address gets the data to the right destination, and the port number tells the transmission layer of the OSI model which application the data is to be sent to. Server Message Block (SMB) and Common Internet File System (CIFS) 400 Appendix ■ Answers to the Review Questions are used in sharing files across a network. Telnet is an unsecure protocol that has been largely replaced by the Secure Shell (SSH) protocol. 18. B. Secure Shell (SSH) can be used to set up a secure session for remote logins or for remotely executing programs and transferring files. SSH uses port 22. SSH has largely replaced the insecure Telnet, which uses port 23. Port 21 is used by File Transfer Protocol (FTP), and port 25 is used by Simple Mail Transfer Protocol (SMTP). 19. A. Private IP addresses are not routable on the Internet. IPv4 network numbers were arranged in classes, and classes A, B, and C each have their own private range. The private IP address range for Class A networks is 10.0.0.0/8. The /8 means that the first 8 bits of the subnet mask denote the network number. Expressing a subnet mask this way is known as CIDR (pronounced cider) notation. CIDR stands for classless interdomain routing. While the term CIDR doesn’t appear on the objectives for this CompTIA A+ exam, you may still run into it while working in IT. 20. D. One of the key features of routers is that they break up broadcast domains. Broadcast traffic from one port of the router will not get passed to the other ports, which greatly reduces network traffic. Bridges, hubs, and switches will all forward broadcast packets. 21. A. Routers are OSI model Layer 3 devices. They keep a chart containing the IP address of the device connected to each port, whether that device is a computer or another router’s external address. A media access control (MAC) address is the address of a network interface card (NIC). Memory addresses identify where information is stored, and a loopback address is used to test TCP/IP on the local host. The loopback address for IPv4 is 127.0.0.1, and for IPv6 it is ::1. 22. C. A loopback plug is for testing the ability of a network adapter to send and receive. The plug gets plugged into the network interface card (NIC), and then a loopback test is performed using troubleshooting software. You can then tell whether the card is working properly. Multimeters are used for testing power supplies and wall outlets, a tone generator and probe help the technician to find a specific wire, and a cable tester checks that an Ethernet wire was configured correctly and that it can make an end-­to-­end connection. 23. D. Category 5, 6, and 7 UTP cables are limited to 100 meters, while Category 8 is limited to only 100 feet, so none of the UTP cables listed will work. You need fiber, and multimode fiber (MMF) can span distances of 300 meters. MMF is also known as OM1, OM2, OM3, OM4, and OM5. OM stands for optical mode. Specifications for each type of multimode fiber are available in the ISO/IEC 11801 standard. 24. C, D. Simple Mail Transfer Protocol (SMTP, port 25), Post Office Protocol 3 (POP3, port 110), and Internet Message Access Protocol (IMAP, port 143) are all email protocols. SMTP is for sending email. POP3 and IMAP are for downloading (receiving) email. Port 23 is used by Telnet. Option B is incorrect because the question specifically asks about downloading (not sending) email. 25. A. Fiber-­optic cabling uses pulses of light instead of electric voltages to transmit data, so it is immune to electrical interference and to wiretapping. UTP, STP, and coaxial are all copper cables, which use electricity to transmit data and so can be subjected to electronic eavesdropping. Chapter 2: Networking 401 26. D. Routers operate at the Network layer (Layer 3) of the OSI model. Because of this, they make their decisions on what to do with traffic based on logical addresses, such as an Internet Protocol (IP) address. Switches use media access control (MAC) addresses and are OSI Layer 2 devices. Hubs and NICs operate primarily at the physical layer (Layer 1). The OSI model is not listed as an objective on the CompTIA A+ exam, but understanding it will help you understand network communications. 27. C. A firewall is a hardware or software solution that serves as your network’s security guard. Firewalls can protect you in two ways: they protect your network resources from hackers lurking in the dark corners of the Internet, and they can simultaneously prevent computers on your network from accessing undesirable content on the Internet or sending out data that they shouldn’t. PoE stands for Power over Ethernet, and EoP stands for Ethernet over Power. Neither has to do with protection. While a router may incorporate a firewall, it is not, by itself, a firewall. Routers are responsible for communications with other networks or broadcast domains. A firewall may be a discrete physical network appliance or software incorporated into another device like a router. 28. D. The default gateway is the address to the network’s router on the LAN side of the router. The router allows the host to communicate with hosts who are not on the local network. The default gateway is also called the router’s internal address. The ipconfig /all command can be used to see the default gateway address that the local computer is currently configured to use. The router will also have an external address, which is used to communicate with networks outside the LAN. Virtually all modern routers use a process called network address translation (NAT), which will substitute the router’s external address for a host’s IP address when requesting information from a remote network. The router knows which host requested the information and will pass it on to the correct host when it is received. This is one of the ways that the router protects the local hosts from the outside world. 29. A. A patch panel can be found in a telecommunications room (also called a wiring closet), usually mounted in a networking rack. On the back will be connections to “punch down” wires into. On the front will be a female port, usually an RJ45 type. A multiplexer is a device that aggregates several connections into one. A rack U is simply a measurement of the height of a device mounted into a rack (e.g., my patch panel is 4U). Each U is equal to 1.75 inches. The demarcation point is where responsibility for a network changes from the ISP to its customer. 30. C. A personal area network (PAN) is a small-­scale network designed around one person within a limited boundary area. The term generally refers to networks that use Bluetooth technology. A local area network (LAN) covers a larger area such as a house or perhaps one floor of a building and likely uses the Ethernet protocol. A metropolitan area network (MAN) covers a larger area such as a city or university campus, and a wide area network (WAN) covers a very large geographic area such as one connecting distant cities or different countries. 31. B. The 169.254.0.0/16 range in IPv4 is the automatic private IP addressing (APIPA) range. APIPA comes into play when the host is unable to locate a Dynamic Host Configuration Protocol (DHCP) server, and the network connection is configured to acquire an IP address dynamically. Since the computer is unable to get a dynamic IP address from the DHCP server, the operating system automatically assigns a random IP address in the APIPA range. 402 Appendix ■ Answers to the Review Questions 32. C. An IPv6 address in the FE80::/10 range is called a link-­local address and is similar to an IPv4 automatic private IP addressing (APIPA) address. (The 169.254.0.0/16 range in IPv4 is the APIPA range, used for automatic configuration if the host can’t locate a Dynamic Host Configuration Protocol [DHCP] server.) Link-­local addresses are generated by the PC when it boots up. Packets using a link-­local address cannot be forwarded by a router. 33. D. Universal Plug and Play (UPnP) is a standard designed to simplify the process of connecting devices to a network and to enable those devices to automatically announce their presence to other devices on the network. In a truly secure environment, UPnP would be disabled, but it is often left enabled on home networks. Dynamic Host Configuration Protocol (DHCP) automatically assigns an IP address to a device when it is powered on, attached to a network, and configured to obtain an address dynamically. Network address translation (NAT) is a feature of routers used to hide the IP addresses of computers on the local network side of the router from the other networks and computers on the outside of the network. Quality of Service (QoS) can be configured to give desired devices preference over others for using network bandwidth. 34. A, C. Addresses in the FE80::/10 range are link-­local unicast addresses. A link-­local address is assigned to each IPv6 interface but is not routable on the Internet. If this is the only address the host has, it will not be able to get on the Internet. 35. A. The File Transfer Protocol (FTP) is optimized for downloading files from servers. It uses port 21. Secure Shell (SSH) uses port 22, Telnet uses port 23, and Hypertext Transfer Protocol (HTTP) uses port 80. 36. D. The Lightweight Directory Access Protocol (LDAP) is a directory services protocol based on the X.500 standard. LDAP is designed to access information stored in an information directory typically known as an LDAP directory or LDAP database. This often includes employee phone numbers and email addresses. Simple Network Management Protocol (SNMP) is used in network monitoring, Simple Mail Transfer Protocol (SMTP) is used in sending email, and Common Internet File System (CIFS) is a filesystem for providing shared access between diverse clients. 37. C. Lightweight Directory Access Protocol (LDAP) is designed to access information stored in an information directory typically known as an LDAP directory or LDAP database. LDAP uses port 389. Port 22 is used by Secure Shell (SSH,) 139 is used by NetBIOS, and 3389 is used by the Remote Desktop Protocol (RDP.) 38. B. The default subnet mask for Class B networks is 255.255.0.0, or written in shorthand, /16. The default subnet mask for Class A networks is 255.0.0.0, or written in shorthand, /8, and for Class C it is 255.255.255.0, or written in shorthand, /24. 255.255.255.255 is an IPv4 broadcast address. As a subnet mask it is represented as /32 (in shorthand) in the classless interdomain routing (CIDR) notation. Chapter 2: Networking 403 39. D. If you’re working on a larger network installation, you might use a punchdown tool. It’s not a testing tool but one that allows you to connect (that is, punch down) the exposed ends of a twisted pair wire into wiring harnesses, such as a 110 block or patch panel. A crimper is used to connect wires to an RJ45 connector, a cable striper removes the outer cover from wires, and a cable tester is used to verify the integrity of a cable. 40. C. Fiber-­optic broadband Internet offers fast speeds (often in the 1–2 Gbps range) but is also the most expensive. Cable may have download speeds up to 1 Gbps (typically 10 to 500 Mbps), but upload speeds are typically only around 5 to 50 Mbps, while fiber-­optic upload speeds may be in the 1 Gbps range. Digital Subscriber Line (DSL) uses plain old telephone service (POTS) lines and is slow. Satellite networks can be faster than DSL, but still only offer speeds up to about 150 Mbps. 41. A, B. IPv4 specifies private (nonroutable) IP address ranges for each class as follows: Class A: 10.0.0.0 to 10.255.255.255, Class B: 172.16.0.0 to 172.31.255.255, and Class C: 192.168.0.0. to 192.168.255.255. Other nonroutable numbers are 127.0.0.1, which is the loopback address, and 169.254.0.0 to 169.254.255.255, which is the automatic private IP addressing (APIPA) range. Class A addresses have a first octet from 0 to 127. Class B’s first octet ranges from 128 to 191. Class C’s first octet ranges from 192 to 223. Numbers above Class C are reserved. 42. C. Server Message Block (SMB) is a protocol used to provide shared access to files, printers, and other network resources. It originally ran on NetBIOS over UDP using ports 137/138 and over TCP using ports 137 and 139, but it’s now part of the TCP/IP stack and uses port 445. Running on NetBIOS allows SMB to facilitate file sharing on a single network, while being part of TCP/IP allows it to facilitate file sharing across the Internet. By itself, SMB is not secure, so it needs other network appliances or software to secure the data being sent over its port(s). File Transfer Protocol (FTP) uses ports 20/21, Secure Shell (SSH) uses port 22, and Simple Network Management Protocol (SNMP) uses ports 161/162. 43. A. All of the answer choices are communications protocols for sharing resources. The Common Internet File System (CIFS) is Microsoft’s version of Server Message Block (SMB.) Once upon a time CIFS was used extensively for file sharing over a network, but it has since fallen out of favor. While CIFS and SMB both facilitate file sharing, SMB does it better and has other features as well. Samba and Network File System (NFS) facilitate sharing files between clients and servers in Linux distributions. Samba will allow mixed environments with both Windows and Linux machines to share files. NFS will not. 44. B, D. Each IPv6 interface can and often does have multiple addresses assigned to it. IPv6 is backward compatible with IPv4 by using tunneling, dual stack, or translation. IPv6 uses multicast addresses in place of broadcast addresses, and a link-­local address is established either automatically when a computer boots up or by manually configuring it, but either way the link-­local address must be present. 45. B. Hubs were once used extensively in Ethernet networks, but they have fallen out of favor because they have a large disadvantage when compared to switches. A hub forms a single collision domain with all of their ports. On a switch, each port is its own collision domain. A switch keeps a table of its ports and the media access control (MAC) address that can be 404 Appendix ■ Answers to the Review Questions reached from each port. A switch will only forward a packet to a specific port, whereas a hub will forward a packet to all of its ports. The exception is that a broadcast packet will be sent to all switch ports. Switches are faster and more accurate than hubs and are used almost exclusively as the connectivity device within a local area network (LAN.) 46. B. The Trivial File Transfer Protocol (TFTP) is a very simple connectionless protocol. It has little overhead, meaning that it doesn’t take much memory to run it. This makes it perfect for booting a thin client across a network. It can be used to transfer the needed boot files to devices that don’t have hard drives. It should not be used to transfer files across the Internet because it is not secure. File Transfer Protocol (FTP) is more robust than TFTP. File Transfer Protocol Secure (FTPS) is a secure version of FTP. Simple Mail Transfer Protocol (SMTP) is used to send email messages. 47. B. 127.0.0.1 is the IPv4 loopback address, used to ping the local network interface. The IPv6 equivalent is ::1. 48. D. If you need to trace a wire in a wall from one location to another, a tone generator and probe is the right tool to use. To use it, attach one end to one end of the cable, such as the end at the computer. Then go to the patch panel with the other end of the probe to locate the cable. These tools are lifesavers when the cables are not properly labeled. A cable tester is used to confirm the integrity of a cable and verity that it is wired correctly. A loopback plug is used to test a network interface card (NIC,) and a punchdown tool is used to terminate wires into a patch panel. 49. B. Dynamic Host Configuration Protocol (DHCP) dynamically assigns IP addresses and other IP configuration information to network clients. The Domain Name System (DNS) translates human-­readable names to their associated IP addresses, the Remote Desktop Protocol (RDP) allows a user to access a computer remotely as if they were sitting there, and Lightweight Directory Access Protocol (LDAP) is used for retrieving information from a database. 50. B. Switches provide centralized connectivity for a LAN. Switches examine the header of incoming packets and forward each to only the port whose associated media access control (MAC) address matches the receiving MAC address in the header. Hubs are seldom used now because the entire hub is one collision domain and when a packet is received, the hub sends the packet out to all of its ports indiscriminately. Bridges are used to connect different networks to