Networking Flashcards

Question

Which TCP/IP configuration information must a computer on a network have before it can communicate with the Internet? (Choose three.) A)TCP/IP address B)FTP server address C)Subnet mask D)Public key E)Proxy server address F)MAC address of router G)Default gateway

Answer 1

A)TCP/IP address C)Subnet mask G)Default gateway Before any computer on a network can communicate with the Internet, it will need an IP address, a default gateway, and a subnet mask. You can supply this information manually (often referred to as a static IP address), or you can use a DCHP server to supply this information automatically (often referred to as a dynamic IP address). If a computer is configured to obtain an IP address automatically, it will contact a DHCP for all client-side DHCP information. The IP address is a 32-digit binary number that is needed to identify each device, or host, on the Internet. The IP address provides a logical address for each device. The subnet mask is used to block out a portion of the IP address. The purpose of the blocking is to distinguish the network ID from the host ID. It is also used to identify whether the IP address of the destination host is on a local network or on a remote network. Subnet mask addresses are 32-bit numbers. Every host on a TCP/IP network will need to be configured with a subnet mask. Use the default subnet mask if you are not dividing your network into subnets. You will need to create custom subnet addresses if your networks are to be divided into subnets. The default gateway is the address of the default router. While you can configure a static IP address, meaning that the IP address is manually entered in the computer's settings, it is considered a best practice to configure the computer to obtain an IP address automatically using Dynamic Host Configuration Protocol (DHCP). Another important part of the IP settings includes configuring the address of the Domain Name System (DNS) server.

Answer 2

A)Remote Assistance Port 3389 is used by the Remote Desktop Protocol (RDP). RDP is the protocol used by Remote Assistance and Remote Desktop in Windows. If this port is closed on your firewall, you will not be able to give remote assistance to remote users. File Transfer Protocol (FTP) uses ports 20 and 21. FTP is a tool that allows a user to transfer files over a network. These ports should only be left open if you specifically use FTP. Hypertext Transfer Protocol (HTTP) uses port 80. HTTP is the protocol used by web pages. Secure Hypertext Transfer Protocol (HTTPS) uses port 443. HTTPS is the protocol used by secure web pages. Post Office Protocol (POP) version 3 uses port 110. POP3 is a mail protocol that retrieves email from an email server. On most networks, this port is open. Telnet uses port 23. Telnet is a tool that allows a user to connect to other computers. Simple Mail Transfer Protocol (SMTP) uses port 25. SMTP is a mail protocol commonly used for outgoing email. On most networks, this port is open. Network News Transfer Protocol (NNTP) uses port 119. NNTP is a news protocol. Internet Message Access Protocol (IMAP) uses port 143. IMAP is a mail protocol.

Answer 3

C)DNS Domain Name System (DNS) is not an Internet appliance. It provides a mapping of IP addresses to domain names. It is analogous to an address book or a telephone directory. Internet appliances, according to the CompTIA A+ exam guide, include UTM, IDS, spam gateways, load balancers, proxy servers, and IPS devices. Unified Threat Management (UTM) devices are Internet appliances. They provide a single point on the network from which multiple security functions are managed. This single point of presence is in contrast to several independent software and devices, such as antivirus, antispam, firewall, IDS, and IPS. Spam gateways are installed behind a firewall and examine all incoming mail to filter out email that is likely to be fraudulent or a phishing email. These gateways can help minimize the risks that spam can pose to organizations. Load balancers are a used by organizations to ensure that servers do not become overburdened from their workload and go down, causing loss of availability. Multiple servers participate in a load-balanced solution, thereby distributing the load. A proxy server acts as an intermediary between an endpoint device, such as a computer, and another server from which a user or client is requesting a service. The proxy server may exist in a firewall server or on a separate server, which forwards requests through the firewall. A proxy server caches web data and images. An intrusion detection system (IDS) is an Internet appliance. It typically sits outside the network and watches packets coming through the network and sets off an alarm if a packet (or series of packets) contains something that violates a defined set of rules. An intrusion prevention system (IPS) is an Internet appliance that sits inline in the network. While it performs many of the same duties as an IDS, an IPS also prevents the offending traffic instead of just detecting it.

Answer 4

F)AD-4F-C1-A9-12-CB The address AD-4F-C1-A9-12-CB is a media access control (MAC) address. A MAC address is assigned to each network interface card (NIC). A MAC address is a 12-digit hexadecimal number. Each pair of hexadecimal numbers is referred to as an octet, and the octets are usually separated by dash (-) characters when a MAC address is represented in text. The first three octets in a MAC address identify the NIC manufacturer, and the last three octets act as a serial number to identify the individual NIC. The address 124.24.0.2 is an Internet Protocol version 4 (IPv4) address. An IPv4 address consists of four 8-digit binary numbers, or octets, separated by periods. A decimal number between 0 and 255 inclusive represents each octet in an IPv4 address. The address 00120193:06F1A345CA11 is an Internetwork Packet Exchange (IPX) address. The six digits before the colon (:) character represent the IPX network address, and the last 12 digits after the colon character represent the node address, which is derived from the MAC address of the NIC. The addresses 1234:EF14:45:ADD1:EA23:222:1290:A, 122A::ABCA:0:0:2100, and ACA1:1345:1::123.23.0.1 are IP version 6 (IPv6) addresses. An IPv6 address is a 128-bit number. The preferred representation of an IPv6 address contains eight sections of hexadecimal numbers. Each section is separated from the other sections by a colon, as in the address 1234:EF14:45:ADD1:EA23:222:1290:A. Each section contains up to four numbers, but leading zeros in each section do not need to be represented. For example, the last section of the IPv6 address 1234:EF14:45:ADD1:EA23:222:1290:A is actually :000A. The IPv6 address 122A::ABCA:0:0:2100 is a compressed format IPv6 address. In a compressed format address, the double colon (::) symbol represents complete sections of zeros. Only one double colon character can appear in a compressed IPv6 address. For example, the IPv6 compressed address 122A::ABCA:0:0:2100 is actually 122A:0:0:0:ABCA:0:0:2100 in uncompressed format. The IPv6 address ACA1:1345:1::123.23.0.1 is a mixed IPv6 address that is designed to support IPv4 addressing. The first six sections of a mixed IPv6 address are written in the hexadecimal notation common to IPv6 addresses. The last four sections of the mixed IPv6 address are a dotted-decimal representation of an IPv4 address. In this example, 123.23.0.1 is the dotted-decimal IPv4 portion of the IPv6 mixed address. Note that this address is also compressed.

Answer 5

C)Ensure the Connect even if the network is not broadcasting option on the Connections tab of the Wireless Network Properties page is cleared. You should ensure the Connect even if the network is not broadcasting option on the Connections tab of the Wireless Network Properties page is cleared. If this option is enabled, probe requests are sent to discover if a non-broadcast network is in range. You should not change the configuration of the Connect automatically when this network is in range option. This option ensures that the connection is reestablished when the wireless network is detected. When you disable automatic configuration of an SSID, the SSID is not automatically transmitted to all computers within the wireless network range. This provides a low level of security. The only way to connect to the wireless network is to enter the SSID manually.

Answer 6

B)The protocol will drop the packets. C)The application will automatically retransmit the packets. User Datagram Protocol (UDP) is a connectionless protocol; thus, it will drop the packets and will not automatically retransmit them. Because an application is not typically responsible for transmitting data packets across a network, the application in this scenario cannot drop the packets. Instead, an application that uses UDP will usually detect that UDP has dropped packets, and the application will retransmit any dropped packets. Other connectionless protocols, such as IP and Internetwork Packet Exchange (IPX), function similarly to UDP. For example, if the application in this scenario were using IPX to transmit data, then IPX would drop the lost packets and the application would retransmit the dropped packets. A connection-oriented protocol, such as TCP or Sequenced Packet Exchange (SPX), will automatically retransmit dropped packets without the intervention of a higher-level protocol or application.

Answer 7

A)To reduce device needs in a data center You would implement a KVM switch to reduce device needs in a data center. A KVM switch allows a user to connect a single keyboard, video display device, and mouse to multiple computers. KVM switches include multiple input connectors, including PS2, VGA, and USB connectors. A switch segments a network. A firewall protects an internal network. A proxy server caches web data and images.

Answer 8

C)CAN A controller area network (CAN) is used in industrial applications, originally in automotive systems. It replaces bulky wiring systems, reducing weight and cost. A CAN builds a network between controllers, allowing them to share information. A railway application, for example, might be a sensor that detects whether or not a door is closed, and locks the brakes until the sensor indicates the door is closed. A storage area network (SAN) creates a network among a pool of storage devices. It may be thought of as a RAID array that uses network connections as opposed to data cables. The SAN pool appears as a single drive letter to the client. A key feature of SAN is multipathing. In a SAN, the physical path between a server and a storage device can fail, and if there is only one pathway available, this failure can cause a network crash. However, SAN multipathing avoids this issue by establishing multiple routes between the hardware so it can route data through multiple paths in the case of a failure. A personal area network (PAN) is a network of devices that are in close proximity to a person, no more than a couple of meters away. Devices that can be part of PANs include wireless headphones, wearable technology, and printers. A metropolitan area network (MAN) connects several LANS together in an area roughly the size of a city. An example of a MAN might be a large hospital with several satellite offices in various neighborhoods around the city. CAN can also mean campus area network. This type of network encompasses a large campus that is usually located within a several-block radius. This type of CAN connects several LANs into a single CAN. Then multiple CANs can be connected using a MAN or WAN.

Answer 9

D)Thin client You should install thin clients in the examination rooms. The computers there will not store any data, but rather serve as a means to collect patient data. The data will be stored on the server at the central office. Because the exam-room computers do not need extensive functionality or an array of productivity applications, thin clients would be sufficient. Thin client computers typically have limited functionality, and they may not even have an operating system. Thick client computers can have an extensive set of applications, and would allow the user to perform operations that a thin client would not. In addition, thick clients perform the majority of their operations on the local client machine instead of on the server. If you installed thick clients in the examination rooms, data would be stored on those machines. If the machines were ever stolen, then the data could be compromised, which is a violation of HIPAA regulations. Servers would not be the best choice for the examination room. Servers should be installed at the central office, where all the records are stored electronically. Tablets may not be the most secure option. They can easily be left in the examination room and forgotten by the nurse, doctor, or medical assistant. It would be an easy matter for the patient to walk out with a tablet that was left behind.

Answer 10

B)It uses 128-bit addresses. C)It has 340 undecillion available addresses. IPv6 uses 128-bit IP addresses and allows for the use of 340 undecillion addresses. IPv4 uses 32-bit addresses and allows for the use of 4 billion addresses.

Answer 11

A)DHCP reservations Dynamic Host Configuration Protocol (DHCP) reservations allow you to assign a relatively permanent IP address to a specific device. When the reservation is created, the IP address is assigned to the device’s MAC address. When the device sends out a DHCP query, the reservation is assigned based on the information in its record. It is often advantageous to assign a permanent IP address to devices like wireless access points, printers, servers, and routers. You can also create a pool of reserved address, such as 192.168.1.200 through 192.168.1.250, to allow for future static assignments. **p 356 A+ Complete Study Guide****** A virtual LAN (VLAN) allows you to segregate network traffic based on the switch port connections. As an example, if computers in the Marketing department are connected to ports 3, 6, 12, and 14, those ports can be assigned to VLAN100. If computers in the Accounting department are connected to ports 4, 15, 17, and 20, those ports can be assigned to VLAN200. Computers on VLAN100 would not be able to communicate with VLAN200, and vice versa. VLAN assignments can span multiple switches, but each switch port can only belong to one VLAN. By default, all switch ports are assigned to VLAN1. Link local addresses in IPv6 begin with FE80::. In IPv6, link-local addressing functions much in the same way that Automatic Private IP Addressing (APIPA) does in IPv4, but link-local addresses are created whether or not DHCP is present. In IPv4, an IP address of 169.254.x.x will be assigned when DHCP server is not available. An APIPA address allows the computer to communicate with other devices on the network. Link-local and APIPA addresses are not routable addresses. Network Address Translation (NAT) allows for the use of a private, non-routable IP address in an internal network. Upon receiving the outbound traffic from the internal network, the router substitutes a routable public IP address and forwards the traffic. When the traffic comes back to the router, the router translates the public address back to the private address and forwards the traffic back to the device on the internal network. Private address are IP addresses that are solely used within a local area network to differentiate different network devices when sending and receiving data streams. Public addresses are Internet-facing addresses that allow devices to communicate with each other that are on separate networks through an internet connection. The most common type of NAT is Port Address Translation (PAT), where the private IP address is assigned an ephemeral port number, and that number is appended to the router’s public IP address.

Answer 12

C)172.16.0.0 Private IP addresses are not valid on the Internet whereas, public IP addresses are valid as nodes on the Internet. They can be resolved and routed across the Internet from one point to another unlike private IP. The following IPv4 address ranges are reserved for private networks: Class A network: 10.0.0.0 - 10.255.255.255 (10/8 prefix) range Used for large network that requires a bigger pool of 16 million private IP addresses Class B network: 172.16.0.0 - 172.31.255.255 (172.16/12 prefix) range Used for medium-sized network that requires 65000 private IP addresses Class C network: 192.168.0.0 - 192.168.255.255 The 172.16.0.0 address is used by Class B private networks. Private network IP addresses are those addresses that are reserved for use on private networks and cannot be used on the Internet. The valid IP address ranges for private networks are **10.0.0.0 to 10.255.255.255, 172.16.0.0 to 172.31.255.255, and 192.168.0.0 to 192.168.255.255.** If you plan to deploy a private IP address range on your network and need to provide Internet access as well, a Network Address Translation (NAT) server will be needed. The 10.0.0.0 address is a Class A IP address for private networks. The 192.168.0.0 address is a Class C IP address for private networks. The 127.0.0.1 address is the software loopback address. The following are the five valid IPv4 address classes: Class A – 1.0.0.0 to 126.0.0.0 Class B – 128.0.0.0 to 191.255.0.0 Class C – 192.0.1.0 to 223.255.255.0 Class D – 224.0.0.0 to 239.255.255.255 Class E – 240.0.0.0 to 255.255.255.255 Classes A, B, and C are valid addresses used on IP networks. Class D addresses are reserved for multicasting. Class E addresses are considered experimental or research addresses and should never be used. All of the ranges that are not part of the private reserved IP address are public addresses.

Answer 13

C)The Domain Name System (DNS) server is down.

Answer 14

A)LDAP Lightweight Directory Access Protocol (LDAP) is used by Active Directory. It is used by applications to access directories. By default, it uses port 389. Server Message Block (SMB) is the application that was responsible for the NetBIOS naming service. NetBIOS names were managed by the old Microsoft WINS servers. It uses ports 137-139 and 445. Secure File Transfer Protocol (SFTP) is a secure version of File Transfer Protocol (FTP) that uses an SSH tunnel. While FTP uses port 20 and 21, SFTP uses port 22. Secure Shell (SSH) is a secure remote terminal application that works over the Internet. SSH uses port 22.

Answer 15

The IPv6 address types should be matched with the given IPv6 addresses as follows: APIPA – fe80::/10 Private – fc00::/7 Loopback – ::1/128 An Internet Protocol Version 6 address (IPv6 address) is a numeric label that is used to identify and locate a network interface of a computer or a network node participating in a computer network using IPv6. IP addresses are included in the packet header to indicate the source and the destination of each packet. The IP address of the destination is used to make decisions about routing IP packets to other networks. IPv6 is the successor to the first addressing infrastructure of the Internet, Internet Protocol version 4 (IPv4). In contrast to IPv4, which defined an IP address as a 32-bit value, IPv6 addresses have a size of 128 bits. Therefore, in comparison, IPv6 has a vastly enlarged address space.

Answer 16

A)Router/switch functionality You will most likely need to assist the user with router/switch functionality. The user is most likely describing an 802.11ac router with a built-in switch. For most small office home office (SOHO) routers, router/switch functionality can be accomplished by running an Ethernet patch cable from a desktop or laptop computer to the router. The IP address (usually 192.168.1.1) is often printed on the bottom of the router, as well as the default username and password. Once you have the IP address, username, and password, open a browser and type in the address. In most circumstances, you will be asked for the username and password. If you entered the IP address, username, and password correctly, you will be able to see the interface used to configure the router/switch functionality you require. The user is not describing an issue with wired or wireless NIC configuration. In Windows 10, NICs can be configured by going to Control Panel > Network and Internet > Network and Sharing Center > View network status and tasks > Change adapter settings, and then selecting the adapter, typically labeled Ethernet. When you right-click the adapter, you will see a pop-up menu where you can adjust the most common settings. Configuring wireless encryption would provide enhanced security, but would not help with the initial configuration issue being described. Cable/DSL modem is not the most likely answer. Cable and DSL modems do not have multiple antennas for wireless. They typically serve as the default gateway for a SOHO network. Cable modems are a type of network bridge that allows for data communication via radio frequency channels to deliver broadband internent access in the form of cabling. DSL is a family of technologies that are used to transmit digital data over telephone lines.

Answer 17

B)Some header fields have been dropped or made optional. F)The IP header options allow more efficient forwarding and less rigid length limits. IPv6 (version 6) or IPng (next generation) offers the following improvements over IPv4: IP address size increases from 32 bits to 128 bits. Some of the header fields have been dropped. Version 6 has less rigid length limits and the ability to introduce new options. Packets will indicate particular traffic type. Support will be provided for data integrity and confidentiality. The IPv6 header is 40 fixed bytes and has eight fields of information.

Answer 18

A)802.11n C)802.11ac Specification Frequency Speed 802.11a 5 GHz up to 54 Mbps 802.11b 2.4 GHz up to 11 Mbps 802.11g 2.4 GHz up to 54 Mbps 802.11n (WiFi 4) 2.4 GHz or 5 GHz up to 600 Mbps 802.11ac (WiFi 5) 5 GHz up to 1,300 Mbps (1.3 Gbps) in 5 GHz with multiple access points 802.11ax (WiFi 6) 2.4 GHz, 5 GHz, or 6 GHz up to 9.6 Gbps, commonly 600 Mbps

Answer 19

D)172.16. through 172.31. The first two octets of a class B private address would range from 172.16 through 172.31. Class B private addresses range from 172.16.x.x through 172.31.x.x. The private address ranges are: * Class A – 10.0.0.0 through 10.255.255.255 * Class B – 172.16.0.0 through 172.31.255.255 * Class C – 192.168.0.0 through 192.168.255.255

Answer 20

A)MAN A metropolitan area network (MAN) would be used by the hospital to connect its various neighborhood offices to the main facility when all are located within the same city or region. MANs connect several LANS together in an area roughly the size of a city. A local area network (LAN) covers a small geographic area. Typically, a LAN is confined to a campus, a single building, a floor of a building, or an area with in a building. A wireless local area network (WLAN) is limited in size by the area(s) served by the access point(s). A wide area network (WAN) uses routers (or a collection of routers) to connect LANs that are dispersed over a large geographic area. An example would be a company with office locations in Boston, Miami, Chicago, Dallas, Denver, and San Francisco. Each office has its own LAN, and routers are used to provide connections between the offices. By building the WAN, the offices can share resources and data. Another type of network topology that you should be familiar with for the Network+ exam is a software-defined wide area network (SDWAN). A SDWAN was created to address modern IT challenges, and was designed to lower operational costs while also improving resource usage during multisite deployments. With a SDWAN, network administrators can use bandwidth more efficiently and can help ensure high levels of performance for critical applications without reducing security or privacy. SDWANs can exist in both cloud and on-premises infrastructures by using virtual WAN architecture.

Answer 21

A)SNMP Of the protocols presented, you should use Simple Network Management Protocol (SNMP) to enable the routers to notify you when they exceed specified performance thresholds. SNMP is a protocol in the Transmission Control Protocol/Internet Protocol (TCP/IP) suite that enables the collection of data about various devices connected to a TCP/IP network, including bridges, hubs, and routers. Each SNMP-compatible device has a Management Information Base (MIB) database that defines the type of information that can be collected about the device. You can also configure SNMP traps to analyze network performance and network problems. A trap is a message that an SNMP-compatible device sends when the device has exceeded a performance threshold. You can configure SNMP to send traps to the network management software you are using, to your email address, or to another destination. Address Resolution Protocol (ARP) is used on a TCP/IP network to resolve Internet Protocol (IP) addresses to media access control (MAC) addresses. TCP/IP uses IP addresses to identify hosts, whereas Ethernet uses MAC addresses to identify network nodes. For Ethernet and TCP/IP to interoperate, a host's IP address must be resolved to a MAC address. You cannot use ARP to notify you when network devices have exceeded performance thresholds. Simple Mail Transfer Protocol (SMTP) is used to transfer email messages from email clients to email servers. SMTP is also used to transfer email messages between email servers. SMTP will not send traps when network devices have exceeded performance thresholds. Telnet is a terminal emulation protocol. You can use Telnet to establish a remote session with a server from a local host through a terminal window to issue commands on the remote server. Telnet client software provides you with a text-based interface and a command line from which you can issue commands on a server that supports the Telnet protocol. Telnet will not send notices when network devices have exceeded established performance thresholds.

Answer 22

Internet of Things (IoT): Incorporates remote sensors Powers home automation and wearable technology Collects and analyzes data using Wi-Fi, Bluetooth, and cloud computing Gains on-board computing power from microcontrollers Supervisory Control and Data Acquisition (SCADA): Incorporates remote sensors Governs critical infrastructure like utilities, transportation, and water treatment Collects and analyzes data using field units, HMIs, and microprocessors Both SCADA and IoT devices use remote sensors to collect environmental data. SCADA is designed to collect field data, transmit it to a centralized location, and display it to an operator through a human-readable interface. A frequent use for IoT is to automate climate control and security systems, which means devices must detect temperature, light levels, and movement. SCADA is a system of software and hardware elements that allows organizations to control automated processes locally or at remote locations; to monitor, gather, and process data; to directly interact with devices like sensors or valves; and to record events into a log file. SCADA is part of the larger category of industrial control systems (ICS), which is a combination of electrical and mechanical components that act together to monitor, control, and safely execute an industrial process in an area like mining, utilities, manufacturing, or transportation. The main components of SCADA are field instrumentation (including sensors), field controllers, human-machine interfaces (HMIs), a network connection, and a means of aggregating the collected data, whether remotely or on-premises. Microprocessors in the field instruments convert the sensor input into usable data. A major weakness of both IoT devices and SCADA is that neither was designed to accommodate secure networking, easy firmware updates, or regular security patching. These are typically after-market considerations handled by third-party applications, not the device or component manufacturers. ICS began as highly specialized hardware and software that ran in physically secured locations without network connections. As IT evolved, legacy ICS systems had new IT capabilities layered on top to provide remote monitoring or "smart" automation. Because ICS components have extremely long lifecycles (decades instead of years), they did not anticipate modern cyber security concerns. For that reason, SCADA and IoT systems are targeted by unique cyber attacks. An Internet of Things (IoT) device is a “smart” device with an embedded microcontroller and connectivity features. The purpose of IoT is to add automation, data collection, and remote control capabilities to physical objects like doorbells, cameras, speakers, appliances, houses, and cars. IoT has rapidly expanded past the consumer market to find uses in industry, healthcare, and transportation as well. A networked IoT technology consists of four main components: Sensing Technology: Sensors integrated in the devices gather data from their environment, such as temperature, gases, location, the operation of some industrial machines, or human biometric data. IoT Gateways: Gateways bridge the gap between IoT devices (internal network) and end users (external network). The gateway sends the data acquired by the sensors in the IoT device to the connected user or the cloud. Cloud Server/Data Storage: The gathered data comes in the cloud after passing via the gateway, where it is stored and subjected to data analysis. The user receives the processed data through an application UI and has the option to take various actions based on the resulting data. Mobile App: The end user monitors, controls, retrieves data, and takes a particular action on IoT devices from a remote location using remote controls such as mobile phones, tablets, computers, and other devices that have a mobile app loaded. IoT devices use a number of different protocols to communicate, including: Bluetooth Low Energy (BLE) Light-Fidelity (Li-Fi) Near Field Communication (NFC) QR codes and barcodes Radio Frequency Identification (RFID) Thread Wi-Fi and Wi-Fi Direct Z-wave ZigBee ANT

Answer 23

A)VLAN A virtual LAN (VLAN) allows you to segregate network traffic based on the switch port connections. As an example, if computers in the Marketing department are connected to ports 3, 6, 12 and 14, those ports can be assigned to VLAN100. If computers in the Accounting department are connected to ports 4, 15, 17, and 20, they can be assigned to VLAN200. In this configuration, computers on VLAN100 would be segregated from computers on VLAN200. VLAN assignments can span multiple switches, but each switch port can only belong to one VLAN. By default, all switch ports are assigned to VLAN1. Link local addresses in IPv6 begin with FE80::. In IPv6, link-local addressing functions much in the same way that Automatic Private IP Addressing (APIPA) does in IPv4, but link-local addresses are created whether or not DHCP is present. In IPv4, an IP address of 169.254.x.x will be assigned when DHCP server is not available. An APIPA address allows the computer to communicate with other devices on the network. Link-local and APIPA addresses are not routable addresses. DHCP reservations allow you to assign a relatively permanent IP address to a specific device. When the reservation is created, the IP address is assigned to the device’s MAC address. When the device sends out a DHCP query, the reservation is assigned based on the information in its record. It is often advantageous to assign a static IP address to devices like wireless access points, printers, servers, and routers. You can also create a pool of reserved address, such as 192.168.1.200 through 192.168.1.250, to allow for future static assignments. Network Address Translation (NAT) allows for the use of a private, non-routable IP address in an internal network. Upon receiving the outbound traffic from the internal network, the router substitutes a routable public IP address and forwards the traffic. When the traffic comes back to the router, the router translates the public address back to the private address and forwards the traffic back to the device on the internal network. Private address are IP addresses that are solely used within a local area network to differentiate different network devices when sending and receiving data streams. Public addresses are Internet-facing addresses that allow devices to communicate with each other that are on separate networks through an internet connection. The most common type of NAT is Port Address Translation (PAT), where the private IP address is assigned an ephemeral port number, and that number is appended to the router’s public IP address.

Answer 24

A)It maps an IP address to a hostname. A pointer (PTR) record maps an IP address to a hostname. A host or address (A) record maps a hostname to an IPv4 address. An AAAA record maps a hostname to an IPv6 address. A mail exchange (MX) record maps a domain name to an e-mail server. A canonical name (CNAME) record contains an alias for an existing A record. A start of authority (SOA) record contains information regarding a particular DNS zone's start of authority. A Domain Name System (DNS) server is the authority for a DNS zone, which contains DNS records. DNS servers allow users to request access to devices using either the devices' hostname or IP address. A DNS server stores fully qualified domain name (FQDN) to IP address mappings. This server allows clients to use the easier-to-remember FQDNs to access remote devices. Dynamic DNS is an implementation of DNS that allows real-time updates to DNS records. With Dynamic DNS (DDNS), devices can automatically update their DNS records or allow a DHCP server to implement the updates on behalf of the DNS client. Text (TXT) records contain human-readable text and are designed to help with fraudulent phishing emails by filtering out emails that are spoofed. Within TXT records, there are three important components that help with spam management. The DomainKeys Identified Mail (DKIM) validates that an email sent from a domain was authorized by the owner of the domain. The Sender Policy Framework (SPF) looks at the addresses of the last SMTP server and verifies that the IP address and SMTP server match to detect spoofing attacks. Lastly, the Domain-based Message Authentication, Reporting, and Conformance (DMARC) system is used to give email domain owners the ability to protect their domain from unauthorized use to prevent spoofing attacks.

Answer 25

B)/24 The network prefix /24 is used to denote an unsubnetted Class C IP address. Class-based IP addresses were the first types of addresses assigned on the Internet. The first octet of a Class A IP address is from 1 through 126 in decimal notation, and the first octet of a Class A IP address is the network address. The first octet of a Class B IP address is from 128 through 191 in decimal notation, and the first two octets of a Class B IP address are the network address. The first octet of a Class C IP address is from 191 through 223, and the first three octets of a Class C IP address are the network address. Each class has a default subnet mask. The default subnet mask for a Class A subnet is 255.0.0.0. The default subnet mask for a Class B network is 255.255.0.0. The default subnet mask for a Class C network is 255.255.255.0. Subnetting was introduced to enable more efficient use of the IP address space. In subnetting, some host bits of a class-based IP address are used as network address bits to enable smaller groupings of IP addresses to be created than the groupings offered by class-based IP addresses. For example, you have an office with 200 computers that reside on four separate networks consisting of 50 computers each. If each network has been assigned its own Class C IP address range, then 204 IP addresses will not be used in each range, for a total of 816 wasted IP addresses. With subnetting, a single Class C IP address range can provide IP addresses for the hosts on all four networks. If you subnetted a single Class C IP address range, then only 48 IP addresses would be wasted. A subnet mask is a 32-bit binary number that can be compared to an IP address to determine which part of the IP address is the host address and which part of the IP address is the network address. Every 1 bit in a subnet mask indicates a bit in the network address, and every 0 bit in the subnet mask indicates a bit in the host address. For example, on a network that uses an unsubnetted Class C IP address range, the IP address 192.168.0.1 has a subnet mask of 255.255.255.0. In binary notation, 255 is represented as 11111111. In binary notation, the subnet mask 255.255.255.0 is represented as 11111111 11111111 11111111 00000000. The binary representation of the IP address 192.168.0.1 is: 11000000 10101000 00000000 00000001 The following is a comparison of the binary subnet mask and the binary IP address: 11111111 11111111 11111111 00000000 Subnet Mask 11000000 10101000 00000000 00000001 IP Address From this comparison, you can see that the first 24 bits of the IP address, or 192.168.0 in decimal notation, are the network address, and the last eight bits of the IP address, or 1 in decimal notation, are the host address. Another method, called a network prefix, is also used to determine which part of an IP address is the network address and which part of an IP address is the host address. The network prefix method appends a slash (/) character and a number after the IP address, as in the following example: 192.168.0.1/24 In this example, the network prefix indicates that the first 24 bits of the IP address, or 192.168.0 in decimal notation, are the network address, and the last eight bits of the IP address are the host address. A range of IP addresses can be expressed very simply with Classless Inter-Domain Routing (CIDR) notation. CIDR notation looks like an IP address followed by a slash with a number–for example, 192.168.0.0/24. The number after the slash is the bit mask for the network. Simply put, it tells you how many bits are the same for each IP on the subnet. This also tells you which parts of the IP addresses can vary, and that gives you the range. 192.168.0.0/24 indicates that the first 24 bits are all the same on this range of IP addresses. The CIDR notation for the range of IP addresses from 192.168.0.0 through 192.168.0.255 is 192.168.0.0/24. The CIDR notation for the 128.1.0.1 through 191.255.255.254 range is 128.1.0.1/2. The CIDR notation for the 69.4.128.0 through 69.4.159.255 is 69.4.128.0/19.

Answer 26

A)Antenna type B)Power considerations D)Regulatory requirements You should consider all of these factors except ethernet jack locations when implementing a long-range wireless network. The power requirements for long-range networks that span several kilometers is very intensive and can become expensive to implement. Understanding these requirements is critical as you must ensure that the wireless system has sufficient power to continuously operate without exceeding power draw regulations. Governmental regulations are unavoidable and must be taken into consideration when operating any form of wireless network. Depending on location, there may be a variety of federal, state, and local laws that you will need to comply with. These regulations can dictate which wireless frequencies can be used, how much power a wireless network can draw, and which types of antennas can/cannot be used. Antenna considerations are another important factor. Both antenna placement as well as the type of antennas used can drastically change the effectiveness of your wireless network. A standard wireless antenna only has a range of 30 meters indoors and 100 meters outdoors, whereas a directional antenna can improve the range of a network to many kilometers within line of sight. Different antennas provide different benefits and drawbacks when it comes to coverage, power consumptions, and cost. Ethernet jack locations would not be a factor, as this is a wireless network. Wireless devices use radio frequencies to transmit data and communicate over a network. For wireless frequencies, between 300 Megahertz (Mhz) and 6 Gigahertz (GHz) provides the optimal communications for modern data transmissions. The Federal Communications Commission (FCC) has licensed radio frequencies within this range to different users and organizations for a fee for the exclusive right to transmit on their assigned frequency within a geographic area in return for no interference. However, organizations can choose to still use airwaves without consulting the FCC and become unlicensed users. Currently there are very few bands that can be utilized by unlicensed groups, which often results in interference occurring from other unlicensed groups using the same frequencies. Whenever implementing a wireless network, it is important to understand what frequencies you will be using, as licensed ones cost more but provide the best performance, and unlicensed ones cost nothing but are often associated with slow performance.

Answer 27

D)Microwave ovens Microwave ovens can cause interference for 802.11b wireless local area networks (WLANs) that operate in the 2.4-GHz frequency band. Microwave ovens operate at the 2.45-GHz frequency band and can cause interference when used in areas where 802.11b WLANs are deployed. Most medical equipment that uses radio frequencies operates in the 2.4-GHz ISM frequency band. Therefore, when doing a site survey, you must consider the interference by microwave ovens, cordless phones, fluorescent lights, and other devices that operate in the 2.4-GHz ISM frequency band, and you should plan the positions of the access points to avoid interference. Pools of water, trees, and construction materials, such as steel and wood, may absorb the radio frequency signals from 802.11b 2.4-GHz WLANs. Objects with water content should be avoided to prevent signal absorption problems. Cellular phones and cable TV cabling do not cause interference with 802.11b WLANs. Keep in mind that wireless networks can be affected by other wireless devices, metal, and water. To overcome interference, you may need to increase the signal strength on the wireless access point. Intermittent wireless can also result from a faulty internal wireless card. Check the internal cable connections for the wireless card if none of the other troubleshooting techniques has solved the problem. A Wi-Fi analyzer (or wireless locator) is a tool that finds nearby wireless networks and displays information about their channels/frequencies, including physical locations, signal levels, SSIDs, and channels in use. A Wi-Fi analyzer can be an app installed on your laptop or phone, or a standalone device with a built-in antenna. Some may display a map of the wireless network showing connected devices.

Answer 28

A)DHCP server A Dynamic Host Configuration Protocol (DHCP) server is responsible for the assignment of IP addresses. IP addresses may be assigned at random (dynamically) or by permanent assignment (static) based on a pool of available addresses. A web server hosts web pages, web services, and web applications. A proxy server acts as an intermediary between an endpoint device, such as a computer, and another server from which a user or client is requesting a service. The proxy server may exist in a firewall server or on a separate server, which forwards requests through the firewall. A proxy server caches web data and images. The Domain Name System (DNS) server maintains the mapping of the relationship between the name of a domain (www.whatever.com) and the corresponding IP address where the domain is hosted. It is analogous to a telephone directory or an address book. For the A+ exam you must also understand the following server roles: * File server (also referred to as fileshare server) – makes documents, spreadsheets, and other files available over the network. * Print server – manages access to printers over the network. Print jobs are sent to the printer using the printer's IP Address. * Mail server – manages user e-mail accounts, serves as a central collection point for incoming emails, delivers e-mail to individual user accounts, and forwards outgoing emails. Examples of mail servers include Microsoft Exchange, Gmail, and Outlook. * Authentication server – validates the credentials of a user or device attempting to access the network. Authentication may come in one of many forms, including username/password, biometrics, and tokens. RADIUS is an example of an authentication server. These servers can provide Authentication, authorization, accounting (AAA) services to ensure that connecting users are valid users, have access only to the services they need, and can track their actions to ensure that their behavior is appropriate. * Syslog Server – Syslog, or System Logging Protocol is a standard protocol that is used to send system log or event messages to a designated server, creating a centralized location where administrators can monitor and respond to any notable events.

Answer 29

D)Wire crimper

Answer 30

The protocols given use these default ports: Port 20 – FTP Port 23 – Telnet Port 25 – SMTP Port 53 – DNS Port 80 – HTTP FTP also uses port 21, but it was not listed in this scenario.

Answer 31

D)Physical device address The physical device, or hardware, address is also referred to as the Media Access Control (MAC) address. A MAC address is a unique number that is assigned to a network interface card (NIC) when the card is manufactured. No two computers on a network can have the same MAC address. The Data Link layer of the OSI model uses these addresses to communicate between devices on local network segments. Although these addresses are considered permanently assigned, some protocols enable them to be changed. An example of a MAC address is 00-AA-00-62-A1-09.

Answer 32

D)Thermostat The user is trying to install a smart thermostat. Smart thermostats are IoT devices that work with low-voltage systems, characterized by several wires in multiple colors. Low-voltage systems typically use 50 volts of electricity or less. Older high-voltage systems use only two or four wires, often labeled as 110 volts AC (110 VAC), 115 volts AC (115 VAC), or 120 volts AC (120 VAC). Smart thermostats are not compatible with older high-voltage systems. Smart light switches are relatively easy to install. Usually, it is simply a matter of removing the old light switch and installing the new one. Light switches typically have a hot (black) wire, a neutral (white) wire, and a copper ground wire and use 110-120 volts in North America. One thing to keep in mind is that the smart light switch takes up more space in the junction box than a standard light switch. Another issue to consider is that a metal junction box may interfere with Zigbee and Z-wave signals. Smart security cameras do not normally require wires other than the power connection. All of their communication is wireless. Smart door locks typically attach to a controller panel mounted on the interior side of the door using one or two wires. An all-mechanical lock that is not a smart lock would not typically have wires coming from it. Other items to consider in IoT device configuration include voice-enabled smart speaker/digital assistants. At the time of this writing, such items include Google Home, Google Assistant, Apple HomePod, and Amazon Alexa.

Answer 33

B)VPN To securely connect to a corporate network from remote locations over the Internet, you should set up a virtual private network (VPN). To set up a VPN connection on an iPhone, go to Settings > General > VPN. Choose Add VPN Configuration, and enter the settings provided to you by the VPN administrator. To configure a VPN connection on an Android device, using the integrated VPN, you should select Wireless and Network Settings under Menu. Then select VPN. In the VPN Screen, select Add VPN Network. Provide the VPN Name and the IP address of the VPN Server, and then save the configuration. When you wish to connect to the VPN, supply the appropriate login credentials and select Connect.

Answer 34

C)fe80::200:f8ff:fe21:67cf An example of an IPv6 address is fe80::200:f8ff:fe21:67cf. An example of an IPv4 address is 127.0.0.1 and 192.1.0.1. An example of a MAC address, which is hard-coded into the network interface card (NIC) by the manufacturer, is 00-0C-F1-56-98-AD.

Answer 35

B)MAC filtering You should use MAC filtering. MAC filtering allows you to specifically configure which computers are allowed on the network, and to specify which computers are denied access to the network. You would include the MAC addresses of departmental computers on an Allow list (referred to as whitelisting). Likewise, you would include MAC addresses of computers that should not be given access on the Block list (referred to blacklisting). Some devices may only allow you to configure an allow or deny list, but not both. Whitelisting/blacklisting is a function of MAC filtering. A demilitarized zone (DMZ) places a firewall between your private network (LAN) and the public network (the Internet) or between two networks. Devices such as web servers and mail servers are often put inside a DMZ, which is also referred to as a screened subnet. Network Address Translation (NAT) allows traffic from a private network to reach the Internet and return. For example, assume a computer on the internal private LAN has an IP address of 192.168.1.140, and the default gateway has an IP address of 71.38.117.45. When traffic from 192.168.1.140 is sent, the gateway assigns it a port number in the ephemeral range, say 45798. The gateway router then uses its own IP address and the assigned port (71.38.117.45:45798) to route traffic to the Internet. Quality of Service (QoS) assigns priorities to different types of network traffic. This allows the network to allocate more bandwidth to traffic with higher priority, and less bandwidth to traffic that you have designated as having a lesser importance. QoS does not affect which device is allowed to access a network.

Answer 36

C. MAC addresses are 48-bit.

Answer 37

B. 1000BASE-T networks need Cat 5 or better UTP.

Answer 38

D. A star bus topology, like the one used with Ethernet networks, is a hybrid topology.

Answer 39

B. Cat 6 cables use an RJ45 connector.

Answer 40

C. Shielded twisted pair cabling handles interference from other electronics much better than unshielded twisted pair.

Answer 41

B. All NICs in a LAN will receive broadcast frames.

Answer 42

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.

Answer 43

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.

Answer 44

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.

Answer 45

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.

Answer 46

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.

Answer 47

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.

Answer 48

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.

Answer 49

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.

Answer 50

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.

Answer 51

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).

Answer 52

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.

Answer 53

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.

Answer 54

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.

Answer 55

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.

Answer 56

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.

Answer 57

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).

Answer 58

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.

Answer 59

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.

Answer 60

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.

Answer 61

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.

Answer 62

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.

Answer 63

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.

Answer 64

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

Answer 65

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.

Answer 66

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.

Answer 67

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.

Answer 68

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.

Answer 69

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.

Answer 70

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.

Answer 71

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.

Answer 72

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.

Answer 73

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.

Answer 74

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.

Answer 75

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.)

Answer 76

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.

Answer 77

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.

Answer 78

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.

Answer 79

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.

Answer 80

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.

Answer 81

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.)

Answer 82

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.

Answer 83

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

Answer 84

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.

Answer 85

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.

Answer 86

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.

Answer 87

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.

Answer 88

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.

Answer 89

C. A cable tester typically uses lights to indicate that the cable is working correctly, and if there is a short, then the indicators for two wires would light up at the same time. Cable testers can range from basic ones that are only a few dollars to very sophisticated ones that are hundreds of dollars. Some of the better ones can tell you how many feet from you that the problem in the cable occurs. A tone generator and probe are used to trace a wire or find a specific wire from a group, a loopback plug is used to test a network interface card (NIC), and a crimper attaches a network wire to its terminator, usually an RJ45 plug.

Answer 90

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.

Answer 91

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.

Answer 92

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.

Answer 93

D. Internet Mail Access Protocol (IMAP) is used to download mail via port 143. Port 80 is for unsecured web page traffic. Ports 25 and 110 are email ports, but they are associated with SMTP and POP3, respectively.

Answer 94

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.

Answer 95

C, D. Punchdown tools are used to connect unshielded twisted pair (UTP) and shielded twisted pair (STP) to a patch panel. A network tap is used to monitor network traffic. The crimper and cable stripper are both needed to add an RJ45 connector to the end of a twisted pair cable. Often both tools are included in one. The stripper removes the outer insulation from the group of wires so that they can be individually inserted into the RJ45 jack. Once the wires are properly inserted, the crimping tool is used to force metal teeth into each wire so that an electrical connection can be made.

Answer 96

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.

Answer 97

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.

Answer 98

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.

Answer 99

D. To encrypt traffic between a web server and client securely, Hypertext Transfer Protocol Secure (HTTPS) can be used. HTTPS connections are secured using either Secure Sockets Layer (SSL) or Transport Layer Security (TLS). HTTPS uses port 443. Port 21 is used by File Transfer Protocol (FTP), port 80 is used by Hypertext Transfer Protocol (HTTP), and port 143 is used by Internet Mail Access Protocol (IMAP).

Answer 100

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.

Answer 101

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).

Answer 102

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.

Answer 103

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.

Answer 104

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.

Answer 105

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.

Answer 106

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.

Answer 107

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).

Answer 108

D. Automatic Private IP Addressing (APIPA) is a TCP/IP standard used to automatically configure IP-based hosts that are unable to reach a Dynamic Host Configuration Protocol (DHCP) server. APIPA addresses are in the 169.254.0.0/16 range. If you see a computer that has an IP address beginning with 169.254, you know that it has configured itself.

Answer 109

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.

Answer 110

D. The Domain Name System (DNS) is responsible for resolving hostnames to IP addresses. This is used millions of times daily on the Internet; when someone types in a website name, such as www.sybex.com, DNS will resolve that to an IP address to enable communication. Address Resolution Protocol (ARP) maps Internet addresses to hardware addresses. Reverse ARP (RAPR) does the opposite, and Dynamic Host Configuration Protocol (DHCP) assigns IP addresses to hosts automatically.

Answer 111

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.

Answer 112

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 host-to-host protocols. Short for User Datagram Protocol and defined in RFC 768, UDP is a network communications protocol. Also called UDP/IP, it is an alternative to TCP/IP that sacrifices reliability for speed and simplicity. Like TCP, UDP transfers packets using IP (Internet Protocol). However, it differs in what data the packets contain, and how the packets are handled by the sender and receiver.

Answer 113

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 114

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 115

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 116

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 117

D. Migrating network configuration to the cloud would allow the network administrator to perform their duties without requiring travel.

Answer 118

A. DHCP uses ports 67/68. Ports 137/139 are for NetBIOS/NetBT. Port 80 is for HTTP, and port 445 is for SMB.

Answer 119

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 120

C. NetBT is NetBIOS over TCP/IP, an older protocol for applications that still rely on NetBIOS. It uses ports 137 and 139, and it's still on the CompTIA A+ certification objectives. DNS uses port 53, SMB uses port 445, and SSH uses port 22.

Answer 121

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 122

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 123

D. Unless an Internet of Things (IoT) device possesses an end-user accessible management interface, that device will likely connect at least initially using Dynamic Host Configuration Protocol (DHCP) to obtain an IP address. Domain Name System (DNS) resolves names like Wiley.com to an IP address. AD is Active Directory, which is a Microsoft client-server security solution, and Single Sign-On (SSO) allows a user to enter their credentials once to access several resources.

Answer 124

A. Radio frequency identification (RFID) can be implemented to detect and read a “passive” (no power) tag that is essentially an antenna as it passes within a few feet in range. RFID tags are often used in industry and retail for inventory tracking. The distance for RFID implementation depends on the size and polarization of the antenna, and the frequency and power used, among other features. NFC requires a distance of only a few centimeters. Wi-Fi is 802.11-based wireless networking. Radio frequency interference (RFI) is a nuisance that can disrupt network communications.

Answer 125

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 126

A. Internet of Things (IoT) devices allow a multitude of personal and industrial devices to connect and communicate over the Internet. Structured Query Language (SQL) is a method of retrieving information from a database. Denial of service (DoS) is a type of network attack, and Encrypting File System (EFS) allows the user to encrypt individual files, folders, or volumes.

Answer 127

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 128

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 129

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 130

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 131

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 132

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 133

C. Mail servers are used to send, receive, and sometimes store and manage emails. They operate on ports 25, 110, and 143. Often devices will need to be configured with the name or IP of the server and the proper protocol or port for sending and receiving email. Web servers provide web pages over the Internet. Authentication servers verify identify before allowing access to resources, and FTP servers are used to quickly locate, download, and upload files.

Answer 134

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 135

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 136

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 137

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 138

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 139

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 140

C. You need to add a wireless access point (WAP), which will have an RJ45 port to connect to the company server and Wi-Fi antennas to provide wireless connectivity. An Ethernet router is wired. A proxy server is a security device. NFC, although wireless and using radio waves, is for connecting devices within a few centimeters of each other.

Answer 141

A. With many new systems added and already booted, it is likely that the DHCP scope, which is a valid range of IP addresses that are available to client-based systems on a particular subnet, is now too small for the number of systems requesting IP addresses. Expand the DHCP scope to solve the problem.

Answer 142

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 143

A. A virtual private network (VPN) uses encryption to secure a transmission across a public network. SDN (software-defined networking) is a network architecture designed to make managing a network easier and more flexible. A VLAN separates a LAN into separate broadcast domains and is used for security purposes. SRAM, or static RAM, is often found in processor cache.

Answer 144

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 145

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 146

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 147

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 11000000. 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 148

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 149

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 150

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 151

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 152

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 153

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 154

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 155

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 156

B. A wireless access point (WAP) provides wireless LAN (WLAN) connectivity, but it may not help with the problems on this network. Your friend needs to determine what wireless channel has the least traffic and configure their Wi-Fi to use that channel. For that they need a Wi-Fi analyzer, which can be a separate device or as simple as an app on a smartphone. A toner probe is used to figure out which network cable is connected when they are not labeled, and a cable tester determines if the cable's wires are connected properly.

Answer 157

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 158

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 159

D. Authentication servers provide the AAA framework for security. Authentication requires that an entity prove who they are before gaining access. Authorization grants the authenticated user access to resources. Accounting tracks user activity.

Answer 160

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 161

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 162

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 163

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 164

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 165

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 166

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 167

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 168

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 169

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.

Answer 170

A)802.11g C)802.11a

Answer 171

C)Subnet mask D)Default gateway F)TCP/IP address

Answer 172

D)Router/switch functionality

Answer 173

A)DHCP is used to automate IP address assignment. DHCP is a protocol that automatically assigns a unique IP address to each device that connects to a network. Dynamic Host Configuration Protocol (DHCP) is a standards-based networking protocol that is used to automate the assignment of IP addresses to DHCP client devices. DHCP is a client/server protocol that uses two components, one on the server and one on the client. The server-side component stores a pool of available IP addresses. The client-side component requests a TCP/IP configuration from an available DHCP server. Several server operating systems support the DHCP server service, including Windows, UNIX, and Linux. Most desktop operating systems support the DHCP client service. Domain Name System (DNS) is a network service that is used to resolve host names to IP addresses. DNS is used extensively on the Internet; for example, DNS can be used to resolve the host name www.verigon.com to that web server's corresponding IP address.

Answer 174

C)Configure the General tab to use the DHCP server at the head office. Configure a static IP address from the branch office network range on the Alternate Configuration tab.

Answer 175

B)Physical device address The physical device, or hardware, address is also referred to as the Media Access Control (MAC) address. A MAC address is a unique number that is assigned to a network interface card (NIC) when the card is manufactured. No two computers on a network can have the same MAC address.

Answer 176

B)Private networks There are three blocks of IP addresses that have been reserved by the Internet Assigned Numbers Authority (IANA) for private networks. These addresses can be used for IP addressing on a private network that does not need to be connected to the Internet. The three blocks of addresses are listed as follows: 10.0.0.0 to 10.255.255.255 172.16.0.0 to 172.31.255.255 192.168.0.0 to 192.168.255.255

Answer 177

A)NFS, TFTP, SNMP User Datagram Protocol (UDP) provides two services that Internet Protocol (IP) does not: a port number to help distinguish different user requests and, optionally, a checksum capability to verify that the data arrived intact. UDP works at the Transport layer of the OSI model. Network applications that want to save processing time use UDP because they have very small data units to exchange, and therefore require a small amount of reassembly. The Trivial File Transfer Protocol (TFTP), Network File System (NFS), and Simple Network Management Protocol (SNMP) use UDP instead of Transmission Control Protocol (TCP). TFTP is a network application that is simpler than File Transfer Protocol (FTP), but less capable. It is used when user authentication and directory visibility are not required. TFTP, FTP, NFS, and SNMP all work at the Application layer of the OSI model.