2.0 Networking - A+ 1101 Flashcards

Question 1

Q

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

Answer

A

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

Question 2

Q

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

Answer

A

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 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.

Question 3

Q

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

Answer

A

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

Question 4

Q

Which one of the following TCP/IP protocols was designed as a replacement for Telnet?
A. SMB
B. SSH
C. SFTP
D. FTPS

Answer

A

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.

Question 5

Q

Which of the following network connectivity devices operates at Layer 2 of the OSI model?
A. Hub
B. Switch
C. Cable
D. Router

Answer

A

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 data link 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.

Question 6

Q

Which of the following TCP/IP protocols is connection-oriented and attempts to guarantee
packet delivery?
A. IP
B. TCP
C. UDP
D. ICMP

Answer

A

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.

Question 7

Q

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

Answer

A

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.

Question 8

Q

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

Answer

A

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.

Question 9

Q

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

Answer

A

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.

Question 10

Q

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

Answer

A

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.

Question 11

Q

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

Answer

A

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.

Question 12

Q

Which type of IPv6 address identifies a single node on the network?
A. Multicast
B. Anycast
C. Unicast
D. Localcast

Answer

A

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

Question 13

Q

Which TCP/IP protocol, developed by Microsoft, uses port 3389 to connect to a
remote computer?
A. RDP
B. SMB
C. CIFS
D. Telnet

Answer

A

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) are used in sharing files across a network. Telnet is an unsecure protocol that has been largely replaced by the Secure Shell (SSH) protocol.

Question 14

Q

What port does the SSH protocol use?
A. 21
B. 22
C. 23
D. 25

Answer

A

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)

Question 15

Q

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

Answer

A

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.

Question 16

Q

Which network connectivity device does not forward broadcast messages, thereby creating
multiple broadcast domains?
A. Hub
B. Switch
C. Bridge
D. Router

Answer

A

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.

Question 17

Q

What type of address does a router use to get data to its destination?
A. IP
B. MAC
C. Memory
D. Loopback

Answer

A

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.

Question 18

Q

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

Answer

A

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

Question 19

Q

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

Answer

A

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.

Question 20

Q

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

Answer

A

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.

Question 21

Q

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

Answer

A

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.

Question 22

Q

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

Answer

A

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).

Question 23

Q

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

Answer

A

D. The default gateway is the address to the network’s router on the LAN side of the router.
T
he 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.

Question 24

Q

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

Answer

A

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

Question 25

Q

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.

Answer

A

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.

Question 26

Q

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

Answer

A

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

Question 27

Q

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

Answer

A

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.

Question 28

Q

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.

Answer

A

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.

Question 29

Q

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

Answer

A

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.

Question 30

Q

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

Answer

A

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.

Question 31

Q

Which of the following Internet connection types offers the fastest download speeds?
A. Cable
B. DSL
C. Fiber-optic
D. Satellite

Answer

A

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.

Question 32

Q

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

Answer

A

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.

Question 33

Q

Which TCP/IP protocol uses port 445?
A. FTP
B. SSH
C. SMB
D. SNMP

Answer

A

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.

Question 34

Q

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

Answer

A

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.

Question 35

Q

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.

Answer

A

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

Question 36

Q

Which network connectivity device is seldom used in modern networks, except to extend
a network?
A. Bridge
B. Hub
C. Switch
D. Router

Answer

A

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 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.)

Question 37

Q

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

Answer

A

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.

Question 38

Q

Which of the following IPv6 addresses is equivalent to 127.0.0.1 in IPv4?
A. ::0
B. ::1
C. ::127
D. 2000::/3

Answer

A

B. 127.0.0.1 is the IPv4 loopback address, used to ping the local network interface. The IPv6 equivalent is ::1.

Question 39

Q

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

Answer

A

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.

Question 40

Q

Which TCP/IP protocol is responsible for dynamically assigning IP addresses to client
computers?
A. DNS
B. DHCP
C. RDP
D. LDAP

Answer

A

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.

Question 41

Q

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

Answer

A

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 work as one, and routers are used to forward packets from one network to other
networks.

Question 42

Q

Which TCP/IP port will an email client use to push email to its email server?
A. 23
B. 25
C. 110
D. 143

Answer

A

B. Email is pushed from clients to servers using the Simple Mail Transfer Protocol (SMTP).

SMTP uses port 25. When trying to remember if SMTP is sending or receiving email, think S for Send.

Port 23 is used by Telnet, now considered insecure and obsolete. Port 110 is used by POP3 (Post Office Protocol 3), and

port 143 is used by IMAP (Internet Mail Access Protocol), both of which are used to retrieve email.

Question 43

Q

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

Answer

A

C. Of the Wi-Fi standards listed, 802.11n has the longest range by default, at roughly 70 meters indoors and 250 meters outdoors. 802.11ac is newer and faster than 802.11n, but it transmits exclusively in the 5 GHz range, which restricts its functional distance.

802.11a, which is legacy and uses the 5 GHz frequency range, could only send a signal about
30 meters,

and 802.11g, which is also legacy but uses the 2.4 GHz frequency range, could only send a signal about 50 meters.

Question 44

Q

What marks the boundary of a IPv4 broadcast domain?
A. Hub
B. Switch
C. Router
D. Modem

Answer

A

C. Hubs send every communication they receive out every connected port. Switches will send broadcast packets out every port, but otherwise will send packets to a specific port based on
the MAC address.

A router will not forward any broadcast packet; therefore a router is the boundary of an IPv4 broadcast domain.

 A modem (modulator/demodulator) converts signals  from one type to another, such as from an analog signal to a digital one.

Question 45

Q

Which TCP/IP protocol gathers and manages network performance information using devices
called agents?
A. SNMP
B. SMTP
C. LDAP
D. SMB

Answer

A

A. Simple Network Management Protocol (SNMP) gathers and manages network
performance information. A management device called an SNMP server can be set up to collect data from these devices (called agents) and ensure that your network is operating properly. SMTP is a mail protocol, LDAP is for accessing database information, and SMB is for
file sharing.

Question 46

Q

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

Answer

A

C. Although Digital Subscriber Line (DSL) is being dropped by some providers in favor of fiber-optic lines, it is still a viable Internet connectivity solution in rural areas that fiber
has not yet reached.

DSL utilizes existing phone lines and provides fairly reliable access
while carrying voice and data on the same lines. Most DSL subscriptions are asymmetrical, meaning they offer faster download speeds than upload speeds.

POTS stands for Plain Old Telephone Service, an acronym from dial-up days. Cable connectivity is provided by cable TV companies.

ISDN is Integrated Services Digital Network, a now obsolete technology that allowed voice and data communication on the same existing telephone lines, similar to DSL.

Question 47

Q

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.

Answer

A

C. When setting up wireless access points, it’s good practice to have their ranges overlap to
ensure that there is no loss of communication when roaming in the network’s area.

However, to avoid problems, it’s best to set up the access points with nonoverlapping channels; in this way, the overlapping ranges ensure continuous signal coverage while the nonoverlapping
channels avoid interference from one WAP to another in the overlapping areas.

Question 48

Q

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

Answer

A

B. The 802.11ac standard has an indoor range of approximately 35 meters. At a minimum,
you will need three access points. Depending on coverage and indoor interference, such as
thick walls, you might need more.

Question 49

Q

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

Answer

A

D. The cable can be any of the three major types, coaxial, twisted pair, or fiber, but it needs to be plenum rated.

Normal cables have a PVC coating, which produces a poisonous gas
when burned. Plenum-rated cables have a Teflon coating, which is not toxic when burned.

Question 50

Q

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

Answer

A

C. The private IP address ranges are 10.0.0.0/8, 172.16.0.0/12, and
192.168.0.0/16. The address 172.168.38.155 is outside the private IP address range
and is a public (routable) address

Question 51

Q

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

Answer

A

C. 802.11b/g transmits in the 2.4 GHz frequency, as does 802.11n, so they are compatible.

The newer 802.11ac is a 5 GHz standard and therefore is not backward compatible with 802.11b/g. 802.11ax transmits in both the 2.4 GHz and 5 GHz frequencies, up to 7 GHz.

802.11r is not a standard related to Wi-Fi speed and is not in the A+ exam objectives.

Question 52

Q

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

Answer

A

A. By configuring Quality of Service (QoS), an administrator can set different priorities for one or more types of network traffic based on different applications, data flows, or users.

UPnP allows devices to identify and connect to other devices on a network.

A screened subnet is a secure area established using a router or routers to protect an internal network from traffic coming to a web-facing server. Port forwarding is configured on a router to send specific traffic to a specific device on a network.

Question 53

Q

Which of the following shorthand notations corresponds to the CIDR subnet mask
255.255.224.0?
A. /19
B. /20
C. /21
D. /22

Answer

A

A. A subnet mask of 255.255.224.0 has 8 bits in each of the first 2 octets set to on, and it has 3 bits in the third octet on. Therefore, it corresponds to /19 in shorthand. In the binary
number system (base two), each bit has two possible values, 0 or 1.

Each bit in an octet going from right to left increments by an exponent of two, making the bits of the octets worth the
decimal values as follows: | 128 |64 |32 |16 | 8 | 4 | 2 | 1 |.

Bits for the subnet mask are always used from left to right, so one bit would be equal to a decimal value of 128. Two bits would
be equal to a decimal value of 192 (128 + 64).

Three bits would be equal to a decimal value of 224 (128 + 64 + 32), and so on. When all 8 bits of the octet are used for the subnet mask,
the equivalent decimal value is 255.

For this example, the first 2 octets (8 bits each) are completely on, and in the third octet, only 3 bits are on, making a total of 19 bits in the subnet mask turned on to indicate the network number (8 + 8 + 3 = 19).

Question 54

Q

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.

Answer

A

A, B. No two nodes on any network, whether IPv4 or IPv6, can have the same IP address because the host portion (or interface ID) of the IP address is what identifies the individual computer on the network. If the network has some machines manually configured, which is generally done with servers, and the remainder of the computers are configured to use

Dynamic Host Configuration Protocol (DHCP), you would need to ensure that the manually
configured numbers are outside of the DHCP scope (the numbers the DHCP server will automatically assign) but within the bounds of the network. For example, in an IPv4 network,
if the network number is 200.100.1.0, the router, which is also acting as a default gateway, might be assigned 200.100.1.1, and numbers from 200.100.1.2 through 200.100.1.20 could
be reserved for static configuration on devices that need an IP address that does not change.

The DHCP scope would need to not include those numbers. If the network needed an available 180 IP addresses, then 200.100.1.21 to 200.100.1.200 could be safely assigned to the
DHCP scope, avoiding any IP address duplication.

Question 55

Q

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

Answer

A

B. To communicate on an IPv4 network, a host must be configured with a valid IP address
and a subnet mask. A default gateway is needed only if the host will connect to a remote network. DNS servers are optional but useful, because they resolve hostnames to IP addresses.

Question 56

Q

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

Answer

A

B, C. Certain devices on a network, such as printers and servers, should have an IP address that doesn’t change (static) so that the other nodes on the network can always find the
device.

Option A is incorrect because if the DHCP lease on the IP address expires, the print
server would be assigned a different IP address the next time it logs in.

A static IP could be configured on the printer server, or the IP address could be configured as reserved on the
DHCP server for that print server.

Either choice would work. Static and dynamic IP addresses almost always exist on the same network, because each is needed to have a network that
runs smoothly.

Question 57

Q

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

Answer

A

D. Wired Equivalent Privacy (WEP) was one of the first security standards for wireless devices.

It uses a static key; the keys are commonly 10, 26, or 58 hexadecimal characters long.

WEP was depreciated in 2004 because it was no longer secure and was replaced temporarily by WPA, which was quickly replaced by WPA2. ‘

WPA3 is the current and most secure standard.

Question 58

Q

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

Answer

A

D. Simple Network Management Protocol (SNMP) uses UDP port 161.

User Datagram Protocol (UDP) is considered connectionless, so it does not guarantee delivery of data packets

and has a lower network overhead than Transmission Control Protocol (TCP), a connection oriented protocol, does. Port 143 is used for IMAP

Question 59

Q

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

Answer

A

B. Clients are unable to get to the DNS server, which resolves hostnames (or URLs) to IP
addresses.

DNS uses port 53. Ports 20 and 21 are used for File Transfer Protocol (FTP).

Ports 67 and 68 are used by Dynamic Host Configuration Protocol (DHCP). Port 80 is used for Hypertext Transfer Protocol (HTTP), and port 443 is HTTP Secure (HTTPS).

Question 60

Q

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

Answer

A

D. Satellite Internet is not much like any other type of broadband connection. Instead of a cabled connection, it uses a satellite dish to receive data from an orbiting satellite and relay
station that is connected to the Internet.

Because it requires a clear line of sight between the
transmitter and receiver, it can be referred to as “line of sight” wireless. Mobile hotspot (cellular) devices are also an option, but they may not be able to reach the speed of a satellite
connection and they depend on a strong cellular signal.

For an installation far from civilization (and cell towers), satellite may be the only option. Cable, DSL, and fiber rely on lines
that would not run as far as a forest ranger lookout tower.

Question 61

Q

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

Answer

A

C. Normal (unsecured) websites are accessed on port 80, which is the port that Hypertext Transfer Protocol (HTTP) uses.

Shut it down, and no one will be able to access websites,
except secure sites that use HTTPS, which is on port 443.

Question 62

Q

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

Answer

A

C. Wireless Internet Service Providers (WISPs) use fixed wireless technology, which requires antennas to send radio waves between your location and a fixed hub on a tower or other tall
structure similar to a cellular tower.

Download speeds can be up to 1 Gbps. Satellite is an
option in very remote areas but has the latency involved with traveling thousands of miles between the connection to the satellite and back again.

Digital Subscriber Line (DSL) uses
telephone lines to create an Internet connection, but many carriers no longer offer DSL.

A cellular hotspot can be used in many remote locations but depends on connection to a cellular tower and is not as fast as satellite

Question 63

Q

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

Answer

A

C. The two host-to-host protocols are Transmission Control Protocol (TCP) and User Datagram Protocol (UDP).

TCP guarantees packet delivery through the use of a virtual circuit
and data acknowledgments, and UDP does not.

Because of this, TCP is often referred to as connection-oriented, whereas UDP is connectionless. IP and ICMP are not considered hostto-host protocols.

Question 64

Q

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

Answer

A

A, B. 802.11a and 802.11g provide throughput that is only 54 Mbps, 802.11n (Wi-Fi 4) provides throughput over 100 Mbps (theoretically up to 300 Mbps),

but 802.11ac (Wi-Fi 5) and
802.11ax (Wi-Fi 6) have far surpassed these standards with throughputs, over 1 Gbps and multiple Gbps, respectively.

Answer 65

A

B, D. 802.11ac operates in the 5 GHz frequency only. 802.11g is only 2.4 GHz. 802.11n and 802.11ax operate in both frequencies.

Answer 66

A

C. NetBIOS over TCP/IP (NetBT) is for older applications still reliant on NetBIOS, the legacy network protocol intended for very small networks.

NetBT lets such applications communicate over TCP/IP.

Trivial File Transfer Protocol (TFTP) is a basic connectionless protocol that allows file transfer functions without user interaction. Hypertext Transfer Protocol Secure (HTTPS) is a secure connection-oriented protocol that runs over port 443

Answer 67

A

B. The distance for Power over Ethernet (PoE) is limited by the maximum distance set by the Ethernet cabling: 100 meters (328 feet).

The power injector, the device that sources the electrical power to certain wires in the cable, can be as much as 100 meters from the powered device.

The injector also needs to have sufficient power to match device needs, and devices must be compatible.

PoE devices such as powered switches can provide a few watts or well over 100 watts, depending on the device.

Answer 68

A

C. An unmanaged switch will simply perform the basic task a switch should do: direct network traffic out the correct destination port.

Prioritizing traffic, configuring virtual LANs
(VLANs), and mirroring ports are all jobs that are done using managed switches.

Answer 69

A

C. The end-user devices are configured to at least request a DHCP-assigned IP address or they are preconfigured with a static IP, gateway, subnet mask, and DNS information.

Answer 70

A

D. MAC address filtering uses the physical address of a NIC to determine whether or not to allow a device to connect to the router. Disabling the SSID will hide the network from neighbors, but it won’t keep them from connecting if they discover the network.

Port forwarding redirects requests for a specific port to a specific device on the network. The DHCP scope can be set up to only allow five machines to connect, but it may not be the right five machines.

Answer 71

A

D. A web server consists of hardware and software used to provide information to remote clients via the Internet. The main protocols for web servers are HTTP and HTTPS, but they
can use other protocols as well.

File Transfer Protocol (FTP) servers are used for downloading files quickly, and while they may have a graphical user interface (GUI), they have much less overhead than a web server. Proxy servers are a security measure between an internal user and

the web and are used to monitor and filter information going into or out of a network.

File servers are often used on a LAN to provide access to the same files by multiple users.

Answer 72

A

C. The file server is a centralized repository for users, typically company employees. File Transfer Protocol (FTP) servers are used for downloading files quickly, and while they may have a graphical user interface (GUI), they have much less overhead than a web server.

Proxy servers are a security measure between an internal user and the web, and they are
used to filter information going into or out of a network, whereas

web servers may provide information about a company or its products to the general public

Answer 73

A

B. Proxy servers act as a gateway through which Internet access requests are handled, monitored, and, if need be, filtered.

File Transfer Protocol (FTP) servers are used for downloading files quickly, and while they may have a graphical user interface (GUI), they have much less overhead than a web server.

File servers are often used on a LAN to provide access
to the same files by multiple users, whereas web servers may provide information about a company or its products to the general public.

Answer 74

A

C. A print server can be either a physical device or software configured on a computer.
The print server provides centralized availability of print services to authorized users on the network. It accepts print jobs, and the documents are printed according to order of receipt or
some configured priority.

A syslog server gathers event information from devices on a network, creating a central repository for a network administrator to monitor and respond to events.

A DNS server resolves domain names to IP addresses, and an authentication server verifies identity before allowing access to a network.

Answer 75

A

A. The File Transfer Protocol (FTP) server hosts files for easy access, allowing users to browse it and download and upload files. Proxy servers monitor and filter traffic into and out of a network.

File servers are a repository of files accessed by multiple users on a network. A DNS server resolves human-readable names such as Wiley.com to an IP address

Answer 76

A

A. The syslog server operates with the Syslog protocol, which is used by many different operating systems and devices. These system-generated messages vary from the mundane
“System started” to critical alerts.

DNS servers resolve domain names to IP addresses. Print
servers facilitate and manage printing by multiple users to one or more printers on a network, and authentication servers verify identity before granting access to a resource

Answer 77

A

B. If a user types www.sybex.com into a web browser, the Domain Name System (DNS) server will resolve the domain name to an IP address. Similarly, DNS servers will resolve
a fully qualified domain named (FQDN) network directory resource on the network to make locating that resource possible.

Syslog servers provide a repository of events on the
network to aid in network management.

Print servers provide and manage access to one or
more printers by multiple users on a network, and an authentication server verifies identity before granting access to resources on a network.

Answer 78

A

D. The authentication server facilitates the challenge/response service for validating someone’s credentials.

Syslog servers provide a repository of events on the network to aid in
network management.

DNS servers resolve URLs to IP addresses, and print servers provide
and manage access to one or more printers by multiple users on a network.

Answer 79

A

C, D. Connection-oriented protocols work over TCP, which guarantees delivery of packets.

This guarantee requires greater resources than UDP, which is connectionless, therefore not requiring that a packet be resent if not received.

HTTPS and SSH are connection-oriented protocols, whereas Trivial File Transfer Protocol (TFTP) and DHCP are connectionless
protocols.

Answer 80

A

B. An intrusion detection system (IDS) will monitor and alert you on suspect behavior.

The IDS can be a network-based device or host-based, meaning it runs as a process in the background.

Proxy servers are used to control traffic into and out of a network. Unified Threat Management (UTM) provides multiple security features on a single appliance.

ATM (Asynchronous Transfer Mode) has to do with transferring different types of traffic (i.e., voice and data) over the same communication lines at the same time.

Answer 81

A

D. The intrusion detection system (IDS) will alert on suspect activity, but it will not react or actively attempt to block the activity. The intrusion prevention system (IPS), however, should attempt to block the activity.

Answer 82

A

C. Unified Threat Management (UTM) systems can be hardware networking devices, virtual devices, or an off-premises service.

UTM’s role is to combine several security features and services into a single device, allowing for easier management and compatibility.

IDSs (intrusion detection systems) will only notify an admin if a threat is detected.

Intrusion protection systems (IPSs) will detect and respond to security threats.

UTP is unshielded twisted pair, a type of network cabling

Answer 83

A

A, D. A Simple Network Management Protocol (SNMP) trap is unrequested information being sent from an SNMP agent, in this case running on a managed switch. SNMP traps are sent via port 162.

Answer 84

A

B. Cellular is the only type of network connection that allows for the type of mobility that this photographer needs.

A cellular hotspot device from a mobile provider would work
well.

Satellite would require repositioning of the dish on a regular basis and may not work
well because of obstructions.

WISP requires being within a few miles of a tower and line of-sight between the antenna and tower, so that wouldn’t work well either. DSL requires a stationary phone line.

Answer 85

A

C. Cable Internet service requires a cable modem to separate the Internet signal from TV channels and to convert the signal into one that your computer can use.

A switch is used
on a LAN as a central connection point. A hub for networking is an obsolete device that would send any signal it received out of all of its ports.

A cable multiplexer connects several signals into one for transmission over a cable, such as input from multiple security cameras.

Answer 86

A

B. Virtual LANs, or VLANs, will segment your network into smaller broadcast domains.

Multiple VLANs can exist on the same physical switch. Traffic is isolated to only the paths determined by how you have identified VLANs on your managed switches.

A VPN (virtual private network) uses tunneling protocols to secure a private connection across a public
network.

A UPS (uninterruptable power supply) is a battery backup with other features used to maintain power to a device when the main power goes down, and

SQL (Structured Query Language) is used to retrieve information from a database.

Answer 87

A

C. Wireless LAN (WLAN) networks commonly have three types of nodes: a client, a router, and a gateway.

They typically don’t include a server and often
are of fluid nature, where devices come and go as needed. They may include a printer.

A WLAN can be used to connect wireless users to a wired network

Answer 88

A

A, B. A NIC can be configured either with a specific (static) IP address, or to obtain an IP
address from an available Dynamic Host Configuration Protocol (DHCP) server. Many
routers have the capability to provide DHCP services. When a device with a properly configured NIC attempts to join a network, a request for an address will be sent to the DHCP
server, and the DHCP server will lease an address to that device, if one is available.

Answer 89

A

B. Option B, 2601::0f:ab:cd:123:4a, and the address in the question both have a
subnet of 0f. IPv6 addresses consist of 128 bits, divided by colons (:) into 8 hextets. Therefore, each hextet represents 16 bits. Leading 0s can be omitted, and in one place in each
address, consecutive groups of 0s can be omitted, represented by double colons (::). The
last 64 bits (4 hextets) of an IPv6 address are the Interface ID, identifying the unique computer. The first 64 bits are called the prefix. ISPs and very large organizations are assigned
/48 prefixes. The next 16-bits (the fourth hextet) are used to define subnets. Option A has a
fourth hextet of 0. Option C is a link-local address. Option D is an invalid number because
hex numbers only go to letter f.

Answer 90

A

B. The third octet’s subnet mask of 192 means that the first 2 bits of the octet are used to
identify the network number, so the network can be broken down into four subnets using
those first 2 bits of the octet. The subnets would be 00000000, 01000000, 10000000, and
IP addresses within each range would be 0 to 63, 64 to 127, 128 to 191, and
192 to 255. The first and last IP in each range would not be used because they would represent the subnet itself and the broadcast numbers. Options A, C, and D all fall in the second
subnet’s range. Option B is in the third subnet.

Answer 91

A

A. The PoE standards are IEEE 802.3af (PoE), 802.3at (PoE+), and 802.3bt (PoE++).
A main difference between the standards is how much power per port can be provided.
802.3af can supply up to 15.4 watts per port, 802.3at can provide up to 30 watts per port,
and 802.3bt can provide 60 watts (Type 3) or 100 watts (Type 4). The power that actually
reaches the devices is less due to voltage loss over distance. 802.3b is a legacy broadband
Ethernet standard. 802.11 and802.11ax are Wi-Fi standards.

Answer 92

A

B, C. PoE devices providing power are backward compatible with older devices, meaning
that while 802.3bt is rated at 60W for Type 3 and 10W for Type 4, an 802.3bt device will
work with an 802.3at (Type 2) device. Option A would not provide enough power for your
friend’s device. Option D is a Wi-Fi standard, not a PoE standard.

Answer 93

A

B, D. ONT (optical network terminal) is installed by a fiber-optic ISP, and it’s typically a
small box on an outside wall. The terminal is a transducer, converting between copper/
electrical signals and fiber-optic/light signals. It does require power, and the terminal may
have an indicator light to signal whether it is receiving power.

Answer 94

A

C. A wireless LAN (WLAN) would be the best solution for this office. A WLAN is a
group of devices in the same location that communicate via radio waves instead of cables.
WLANS can have multiple wireless access points (WAPs), preferably overlapping so that
users won’t experience signal drop. Wi-Fi is a type of WLAN. A LAN is incorrect because it
would require disconnecting and reconnecting cables in each room. A VLAN (virtual LAN)
is established using security protocols to segregate a network. WAN is incorrect because
this is a network in a single office, not geographically distant computers.

Answer 95

A

C. Software-defined networking (SDN) has many advantages over traditional networking.
It can work with virtual and physical networks using SDN-compatible devices, providing
centralized control of the entire network and the ability to reconfigure networks often
without having to physically touch a router or switch.

Answer 96

A

B. Frequencies for wireless Internet service providers (WISPs) can be licensed or unlicensed.
(The FCC is the licensing body.) Most WISPs use the unlicensed frequencies because they
are free to use.

Answer 97

A

B. A fileshare server handles requests from fileshare clients for access to data stored on the
server. The fileshare server resides on the same machine as the data. A client access license
(CAL) is a license allowing one machine to connect to a server, and SAN is a storage area
network, both of which are unrelated to the question

Answer 98

A

C. A storage area network (SAN) is a high-speed network whose purpose is to provide fast
access by servers to storage. Network attached storage (NAS) differs from a SAN in that it
is not a separate high-speed network but a single storage device attached to a LAN. SAS is
statistical analysis software, and WAN is wide area network.

Answer 99

A

A, D. A network terminal access point (TAP) connects to a network in an area of concern
and creates a copy of traffic, sending it on to monitoring devices. It can be an integral part
of network management. TAPs can be active or passive. Passive TAPs do not require power
or management, but active TAPs do.

Answer 100

A

B. Wireless Internet service providers (WISPs) that are operating in the 2.4 GHz band are
limited to 4 watts of effective isotropic radiated power (EIRP) for their point-to-multipoint
connections. Their point-to-point connections vary between 4 watts and 158 watts for the
2.4 GHz band. The maximum EIRP for the 5 GHz bands is 125 mw. FCC maximums can
be found at www.air802.com/fcc-rules-and-regulations.html.

Answer 101

A

A. Channels 36 to 48 are set aside for domestic use. All channels above that require a
router to have DFS and TPC. DFS will automatically switch to a different channel when
weather radar and radar system signals are detected. TPC can be used to force clients to
lower power so that they won’t interfere with nearby users or access points on the same
channel. Channel 165 is set aside for industrial, scientific, and medical (ISM) use. In the
United States, the FCC and IEEE are the authorities that approve channel uses.

Answer 102

A

B. The FCC’s ruling was expanded to include long-range fixed wireless hub or relay
antennas and the customer’s right to place antennas of certain sizes on their premises,
putting WISP providers on a more equal footing with satellite and cellular providers.

Answer 103

A

D. When an IP address and subnet mask are converted to the binary numbers that the
computer sees, wherever there is a 1 in the subnet mask, that tells the computer that the
corresponding bit in the IP address is part of the network number. Wherever there is a
0 in the subnet mask, the corresponding bit in the IP address is part of the host number.
The address in the question, 192.168.2.200/24, is a Class C private address, where,
in the subnet mask, the first three octets (24 bits) are all 1s, and the last octet (8 bits) are
0s. So, the first three decimal numbers of the IP address, which is expressed in dotted decimal notation, are the network number, (192.168.2) and the last octet (.200) is the host
(individual computer) address. Network numbers will always go from left to right with no
breaks between.

Answer 104

A

C. Load balancers do as their name implies. Rather than allow all incoming traffic on a
port to go to one server or device, the traffic is distributed among devices. Proxy servers
monitor incoming and outgoing packets, filtering them out based on specified criteria.
Spam gateways don’t allow spam in; rather they are used to filter it out. Unified threat
management (UTM) can employ an appliance or be software-driven, or even an outside
service that monitors and manages malicious activities against a network.

Answer 105

A

A. Supervisory Control and Data Acquisition (SCADA) systems consist of both hardware
and software. Hardware is used to gather information, which is sent to a computer running
software that analyzes the data and logs events. SCADA can also initiate alarms when
specified conditions exist. Infrared Data Association (IrDA) is network communications
via infrared light. Unified threat management (UTM) is an appliance, software, or service
that combines all malware security in one place. Remote Authentication Dial-In User Service (RADIUS) is a protocol for authentication servers that encrypts transmissions between
client and server.

Answer 106

A

C. A DHCP server will “lease” an IP address to a client for a specified period of time. The
default is usually 24 hours. In a SOHO where there are few new users, the lease time could
be longer, but in a restaurant where many people come and go each hour, the DHCP scope
might not have enough addresses to accommodate that many users. Setting the lease time
to a shorter duration will release the IP address and make it available for a new user. MAC
address filtering only allows connection from computers with specific MAC addresses and
would greatly limit connectivity. Port forwarding sends traffic for a specific port to a specified computer on the network. The SSID is the wireless network name and can be broadcast
so that it is easily found, or it can be hidden.

Answer 107

A

B. The Domain Name System (DNS) uses two types of records to resolve domain names
to IP addresses. Type A records resolve the domain name to IPv4 addresses. Type AAAA
records resolve domain names to IPv6 addresses. MAC and Physical addresses are two
names for the NIC address.

Answer 108

A

A. Multiple Mail Exchanger (MX) records can be set up for a domain that specify different
mail servers for load balancing. Direct Connect (DX) is an Amazon Web Services dedicated
connection between client and AWS. AAAA signifies an IPv6 address in a DNS record, and
TXT DNS records let an administrator specify text in their DNS record. These text records
can be used to prevent email spam.

Answer 109

A

B. Sender Policy Framework (SPF) is a technique to prevent email address spoofing. It is
done using a TXT entry in a domain’s DNS service. DomainKeys Identified Mail (DKIM)
performs a similar function, but it uses a digital signature. Domain-Based Message Authentication, Reporting, and Conformance (DMARC) uses SPF or DKIM and in addition
requires that the sender’s domain be the same as the DNS domain name. Domain administrators can specify to quarantine or reject emails that fail DMARC. To use DMARC, a
DMARC record must exist in the DNS.

Answer 110

A

C. This is an IPv6 address. It is 128 bits long, and the last 64 bits are the interface
ID, which identifies the individual computer. Since there are eight groups of hex numbers, that means the rightmost four groups are the interface ID. Any leading zeros in an
IPv6 address can be omitted, and the :: can be used once in an address to replace consecutive groups of all zeros, so the number in the question fully expanded would be
2001:0000:0000:0000:01a3:0f1a:0308:0833. The interface ID is therefore
1a3:f1a:308:833. The leftmost three sections identify the network, and the fourth identifies the subnet. In this example, 2001:0:0 is the site prefix and 0 is the subnet ID. IPv6
addresses do not need a subnet mask like IPv4 addresses do

Answer 111

A

A, D. For decades now, wireless Internet service providers (WISPs) have been established
by groups of individuals or small companies to provide Internet access to areas where it is
not profitable for large commercial Internet providers to run, such as very rural areas. They
are also called long-range fixed wireless providers. The first one was established in 1992 in
the Midwest of the United States. Now there are thousands of them all over the world. In
some areas of the world, where there is little or no wired infrastructure, WISPs are the only
way that people can get Internet connectivity. A WISP connects to the Internet using either
leased lines or microwaves, generally uses point-to-point microwaves between its towers,
and uses point-to-multipoint connections between the final tower and users. An ISP is an
Internet service provider, and a demarcation point is the place in a customer’s premises
where the responsibility for the network changes from the ISP to the customer.

Answer 112

A

A, B. Option A is true. Channels 1, 6, and 11 are the only ones that don’t overlap in a
2.4 GHz network. Option B is also true. Each channel in a 2.4 GHz network is only about
5 MHz wide, while in a 5 GHz network the minimum is 20 MHz, but it can be configured to use 40 MHz or 80 MHz by combining channels. Option C is false. The 2.4 GHz
frequency supports older devices; the 5 GHz frequency is newer. While 2.4 GHz channels
overlap with the exception of 1, 6, and 11, 5 GHz channels don’t overlap. Your friend
needs to choose a frequency and channel that are compatible with their devices, but the
router may automatically configure the channel if using the 5 GHz frequency.

Answer 113

A

C. The Institute of Electrical and Electronics Engineers (IEEE) 802.11ax standard is now
known as Wi-Fi 6, and is considered a replacement for 802.11ac (Wi-Fi 5). 802.11n is
designated as Wi-Fi 4. Prior IEEE standards (802.11b, 802.11a, and 802.11g) are not
designated with official Wi-Fi X nomenclature, but working backward in time, 802.11g
would be Wi-Fi 3, 802.11a would be Wi-Fi 2, and 802.11b would be Wi-Fi 1. The CompTIA A+ objectives only ask that you know what Wi-Fi 5 and Wi-Fi 6 are.

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