"Which feature is characteristic of MAC filtering in wireless networks?"

"It restricts computer access to a wireless network."

"It is configured on the computer rather than on the router."

"It encrypts data that is transmitted on a wireless network."

"It allows only authorized users to detect the network."

"A"

"MAC address filtering uses the MAC address to identify which devices are allowed to connect to the wireless network."

"A user is setting up a home wireless network. Which type of device must the user have in order to establish the wireless network and provide access to the internet for multiple home devices?"

"wireless router"

"switch"

"hub"

"patch panel"

"A"

"A wireless router connects multiple wireless devices to the network. It will then aggregate the internet access requests from home devices to the internet."

"What is the order of bandwidth measurement from smallest to largest?"

"Tbps, Mbps, Kbps, Gbps"

"Kbps, Tbps, Mbps, Gbps"

"Gbps, Tbps, Mbps, Kbps"

"Kbps, Mbps, Gbps, Tbps"

"D"

"Command bandwidth measurements are as follows from smallest to largest:Thousands of bits per second (Kbps) or Kilobits per secondMillions of bits per second (Mbps) or Megabits per secondBillions of bits per second (Gbps) or Gigabits per secondTrillions of bits per second (Tbps) or Terabits per second"

"Which is a characteristic of the Internet?"

"It is not centrally governed."

"It is localized to specific geographic locations."

"It supports only wired network connections."

"It is operated by the US government."

"A"

"The Internet is a global system of interconnected computer networks that has no central governance. It is not limited to geographic boundaries and uses static public IP addresses for communication."

"What allows digital devices to interconnect and transmit data?"

"a global positioning sensor"

"a smart phone"

"a network"

"a sensor"

"C"

"A network connects people and devices through wired or wireless means."

"A consumer places a smartphone close to a pay terminal at a store and the shopping charge is successfully paid. Which type of wireless technology was used?"

"NFC"

"Bluetooth"

"3G"

"Wi-Fi"

"A"

"NFC is a wireless technology that allows data to be exchanged between devices that are in very close proximity to each other."

"Which security measure is best used to limit the success of a reconnaissance attack from within a campus area network?"

"Implement encryption for sensitive traffic."

"Implement access lists on the border router."

"Implement a firewall at the edge of the network."

"Implement restrictions on the use of ICMP echo-reply messages."

"A"

"The implementation of an access list may provide extra security by permitting denying a flow of traffic, but it will not provide a direct response to limit the success of the attack. The implementation of a firewall on the network edge may prevent reconnaissance attacks from the Internet, but attacks within the local network are not prevented. By implementing restrictions on the sending of ICMP echo-reply messages within a local network, devices may not respond to ping messages, but port scans are not prevented and clear-text data sent on the network are still vulnerable. The best security measure is to encrypt as much network traffic as possible, both user data and network management traffic."

"Which attack involves threat actors positioning themselves between a source and destination with the intent of transparently monitoring, capturing, and controlling the communication?"

"DoS attack"

"man-in-the-middle attack"

"ICMP attack"

"SYN flood attack"

"B"

"The man-in-the-middle attack is a common IP-related attack where threat actors position themselves between a source and destination to transparently monitor, capture, and control the communication."

"What is the motivation of a white hat attacker?"

"discovering weaknesses of networks and systems to improve the security level of these systems"

"taking advantage of any vulnerability for illegal personal gain"

"studying operating systems of various platforms to develop a new system"

"fine tuning network devices to improve their performance and efficiency"

"A"

"White hat attackers break into networks or computer systems in order to discover weaknesses for the purpose of improving the security of these systems. These break-ins are done with permission from the owner or the organization. Any results are reported back to the owner or the organization."

"What is the purpose of a reconnaissance attack on a computer network?"

"to redirect data traffic so that it can be monitored"

"to prevent users from accessing network resources"

"to steal data from the network servers"

"to gather information about the target network and system"

"D"

"Curriculum Reference: Module 1.1This item is based on information contained in the presentation.Preventing users from accessing network resources is a denial of service attack. Being able to steal data from the network servers may be the objective after a reconnaissance attack gathers information about the target network and system. Redirecting data traffic so it can be monitored is a man-in-the middle attack."

"An administrator is in the process of changing the configuration of a router. What command will allow the administrator to check the changes that have been made prior to saving the new configuration?"

"Router# show startup-config"

"Router# show current-config"

"Router# show running-config"

"Router# show memory"

null

"Which functionality does split horizon provide?"

"it Prevents routing loops in distance vector protocols"

"it Prevents switching loops in distance vector protocols"

"it Prevents switching loops in link-state protocols"

"it Prevents routing loops in link-state protocols"

null

"What can you change to select switch as root bridge?"

"make lower priority"

"make higher priority"

"make lower path cost"

"make higher path cost"

null

"Under which circumstance should a network administrator implement one-way NAT?"

"when traffic that originates outside the network must be routed to internal hosts"

"when the network has few public IP addresses and many private IP addresses require outside access"

"when traffic that originates inside the network must be routed to internal hosts"

"when the network must route UDP traffic"

null

"Which statement about a router on a stick is true?"

"Its data plane routes traffic for a single VLAN over two or more switches."

"It uses multiple subinterfaces of a single interface to encapsulate traffic for different VLANs on the same subnet"

"It requires the native VLAN to be disabled."

"It uses multiple subinterfaces of a single interface to encapsulate traffic for different VLANs."

null

"Two hosts are attached to a switch with the default configuration. Which statement about the configuration is true?"

"The two hosts are in the same broadcast domain."

"IP routing must be enabled to allow the two hosts to communicate"

"The switch must be configured with a VLAN to allow the two hosts to communicate."

"Port security prevents the hosts from connecting to the switch."

null

"Which NTP concept indicates the distance between a device and the reliable time source?"

"clock offset"

"stratum"

"reference"

"dispersion"

null

"Which NAT term is defined as a group of addresses available for NAT use?"

"NAT pool"

"dynamic NAT"

"static NAT"

"one-way NAT"

null

"What does administrative distance refer to?"

"the cost of a link between two neighboring routers"

"the advertised cost to reach a network"

"the cost to reach a network that is administratively set"

"a measure of the trustworthiness of a routing information source"

null

"Which MTU size can cause a baby giant error?"

"1500"

"9216"

"1600"

"1518"

null

"Which function enables an administrator to route multiple VLANs on a router?"

"IEEE 802.1X"

"HSRP"

"port channel"

"router on a stick"

null

"A workstation has just resolved a browser URL to the IP address of a server. Which protocol will the workstation now use to determine the destination MAC address to be placed into frames directed toward the sever?"

"ARP"

"RARP"

"DNS"

"DHCP"

null

"Which option is the default switch port port-security violation mode?"

"shutdown"

"protect"

"shutdown vlan"

"restrict"

null

"Why would a network administrator configure port security on a switch?"

"to limit the number of Layer 2 broadcasts on a particular switch port"

"to prevent unauthorized Telnet access to a switch port"

"to prevent unauthorized hosts from accessing the LAN"

"block unauthorized access to the switch management interfaces"

null

"Which port-security feature allows a switch to learn MAC addresses dynamically and add them to the running configuration?"

"security violation restrict mode"

"switch port protection"

"sticky learning"

"security violation protect mode"

null

"Which of the following command can be used to access all the files in a system?"

"syslog"

"IFS"

"ping"

"NTP"

"B"

null

"What is the default value of the Read-Write-All-SNMP community string?"

"Secret"

"Private"

"Public"

"Cisco"

"A"

null

"A user is looking for a wireless headphone for listening to songs stored on a smartphone. What wireless technology would the headphone use?"

"Bluetooth"

"infrared"

"Wi-Fi"

"3G/4G"

"A"

"Bluetooth is a wireless technology for data exchange over a short distance. It is suitable for connecting devices with simple tasks, such as headsets, keyboards, mice, and printers. Wi-Fi is suitable for variety of applications with high speed wireless connectivity required or preferred. Infrared requires a direct line of sight between the transmitter and the receiver. 3G/4G are cellular network technologies to manage voice calls and data transmission between clients and service providers."

"In the context of mobile devices, what does the term tethering involve?"

"connecting a mobile device to a hands-free headset"

"connecting a mobile device to a 4G cellular network"

"connecting a mobile device to a USB port on a computer in order to charge the mobile device"

"connecting a mobile device to another mobile device or computer to share a network connection"

"D"

"Tethering allows a laptop or PC to use the Internet connection of a mobile device such as a cell phone, usually through a cellular data connection. This allows devices to connect to the Internet in locations where there is no Wi-Fi or cabled connection, but where there is still a cellular data connection."

"Which technology is used to uniquely identify a WLAN network?"

"WPA"

"SSID"

"WEP"

"MAC address table"

"B"

"When a wireless AP or router is being set up, an SSID is configured to uniquely identify the WLAN that is managed by the device."

"Which wireless RF band do IEEE 802.11b/g devices use?"

"5 GHz"

"2.4 GHz"

"60 GHz"

"900 MHz"

"B"

"900 MHz is an FCC wireless technology that was used before development of the 802.11 standards. 900 MHz devices have a larger coverage range than the higher frequencies have and do not require line of sight between devices. 802.11b/g/n/ad devices all operate at 2.4 GHz. 802.11a/n/ac/ad devices operate at 5 GHz, and 802.11ad devices operate at 60 GHz."

"Which items are collectively referred to as network media?"

"firewalls and servers"

"PCs and laptops"

"wires and radio waves"

"routers and switches"

"C"

"Network media is a term used to describe the actual physical layer transport along the path over which an electrical signal travels as it moves from one component to another."

"What information may be requested when pairing devices over Bluetooth?"

"a PIN"

"an IP address"

"the SSID"

"a username"

"A"

"During the pairing process, a personal identification number (PIN) may be requested for authentication."

"Which statement defines a data communications protocol?"

"an exchange agreement of network devices among vendors"

"an alliance of network device manufacturers"

"a set of product standards for types of network devices"

"a set of rules that govern the communication process"

"D"

"A data communication protocol is a set of rules that govern the communication process."

"Which statement is true about the TCP/IP and OSI models?"

"The TCP/IP network access layer has similar functions to the OSI network layer."

"The first three OSI layers describe general services that are also provided by the TCP/IP internet layer."

"The TCP/IP transport layer and OSI Layer 4 provide similar services and functions."

"The OSI Layer 7 and the TCP/IP application layer provide identical functions."

"C"

"The TCP/IP internet layer provides the same function as the OSI network layer. The transport layer of both the TCP/IP and OSI models provides the same function. The TCP/IP application layer includes the same functions as OSI Layers 5, 6, and 7."

"Which data encoding technology is used in fiber-optic cables?"

"modulation of electrical voltage"

"pulses of light"

"electrical pulses"

"modulation of specific frequencies of electromagnetic waves"

"B"

"Data is transmitted across a network on media. Modern networks primarily use three types of media to interconnect devices:Metal wires within cables (copper cable, such as twisted-pair and coaxial cable) – Data is encoded into electrical impulses.Glass or plastic fibers within cables (fiber-optic cable) – Data is encoded into pulses of light.Wireless transmission – Data is encoded via modulation of specific frequencies of electromagnetic waves."

"What is one advantage of using fiber optic cabling rather than copper cabling?"

"It is able to carry signals much farther than copper cabling."

"It is usually cheaper than copper cabling."

"It is easier to terminate and install than copper cabling."

"It is able to be installed around sharp bends."

"A"

"Copper cabling is usually cheaper and easier to install than fiber optic cabling. However, fiber cables generally have a much greater signaling range than copper."

"Which type of network cable is commonly used in backbone networks and telephone companies?"

"shielded twisted-pair cable"

"fiber-optic cable"

"twisted-pair cable"

"coaxial cable"

"B"

"Fiber-optic cables can carry very large amounts of data and are used extensively by telephone companies and in backbone networks."

"Which criterion can be used to select the appropriate type of network media for a network?"

"the cost of the end devices that are used in the network"

"the number of intermediary devices that are installed in the network"

"the types of data that need to be prioritized"

"the environment where the selected medium is to be installed"

"D"

"Criteria for choosing a network medium are the distance across which the selected medium can successfully carry a signal, the environment in which the selected medium is to be installed, the amount of data and the speed at which the data must be transmitted, and the cost of the medium and its installation."

"Which type of address does a switch use to build the MAC address table?"

"destination IP address"

"source IP address"

"source MAC address"

"destination MAC address"

"C"

"When a switch receives a frame with a source MAC address that is not in the MAC address table, the switch will add that MAC address to the table and map that address to a specific port. Switches do not use IP addressing in the MAC address table."

"Which term refers to the process of placing one message format inside another message format?"

"segmenting"

"encoding"

"encapsulation"

"manipulation"

"C"

"Encapsulation is the process of placing one type of message format into another. On computer networks this process is known as encapsulation. Once a message is encapsulated, it is called a frame."

"How much data can be encapsulated into a normal sized Ethernet frame before it is sent over the network?"

"32 to 1500 bytes"

"64 to 1518 bytes"

"46 to 1500 bytes"

"0 to 1024 bytes"

"C"

"According to the Ethernet standards, each Ethernet frame can carry 46 to 1500 bytes of user data. During the encapsulation process, other fields are added, such as destination MAC address, source MAC address, and FCS. The size of Ethernet frames is normally limited to a maximum of 1518 bytes and a minimum of 64 bytes."

"How many bits make up an IPv4 address?"

"48"

"64"

"128"

"32"

"D"

"An IPv4 address is a 32-bit logical address."

"When IPv4 is configured for a computer on a network, what does the subnet mask identify?"

"the device that the computer uses to access another network"

"the part of the IP address that identifies the network"

"the dynamic subnetwork configuration"

"the pool of addresses assigned within the network"

"B"

"The IP addressing system is a hierarchical addressing system. An IP address is made up of two parts: the network address and the host address. For IPv4, the subnet mask is used to identify which portion of an IPv4 address is the network address and which portion is the host address."

"What is the purpose of the subnet mask in conjunction with an IP address?"

"to identify whether the address is public or private"

"to uniquely identify a host on a network"

"to mask the IP address to outsiders"

"to determine the subnet to which the host belongs"

"D"

"With the IPv4 address, a subnet mask is also necessary. A subnet mask is a special type of IPv4 address that coupled with the IP address determines the subnet of which the device is a member."

"A student is helping a friend with a home computer that can no longer access the Internet. Upon investigation, the student discovers that the computer has been assigned the IP address 169.254.100.88. What could cause a computer to get such an IP address?"

"reduced computer power supply output"

"interference from surrounding devices"

"unreachable DHCP server"

"static IP addressing with incomplete information"

"C"

"When a PC does not have a static IP address or cannot pick one up from a DHCP server, Windows will automatically assign the PC an IP address using APIPA, that uses the range of addresses 169.254.0.0 to 169.254.255.255."

"What is one factor increasing the adoption of IPv6 network addresses?"

"IPv4 addresses cannot coexist with IPv6 addresses on the internet."

"IoT adds millions of network-ready sensors that need IP addresses."

"Devices communicate faster using IPv6 addresses than when using IPv4."

"IPv4 will no longer be supported on mobile devices."

"B"

"Factors that are driving an increase in IPv6 adoption are an increasing internet population, a limited IPv4 address space, issues with NAT and the large number of internet-ready IoT devices."

"When the IETF began development of IPv6, what was the goal of implementing this technology?"

"to increase the limiting 128 bits available in IPv4 to facilitate the growing Internet"

"to make reading a 32-bit address easier"

"to relieve IPv4 address depletion"

"to provide more address space in the Internet Names Registry"

"C"

"IPv6 is designed to be the successor to IPv4. IPv6 has a larger 128 bit address space to provide many more addresses than IPv4."

"What is the valid most compressed format possible of the IPv6 address 2001:0DB8:0000:AB00:0000:0000:0000:1234?"

"2001:DB8:0:AB:0:1234"

"2001:DB8:0:AB00::1234"

"2001:DB8::AB00::1234"

"2001:DB8:0:AB::1234"

"B"

"There are two rules defining how an IPv6 address can be compressed. The first rule states that leading zeros in a hextet can be eliminated. The second rule states that a single :: can be used to represent one or more contiguous all zero hextets. There can be one and only one :: in an IPv6 address."

"Which shortened address is an accurate representation of the IPv6 address 2001:0db8:0000:0000:ab00:0000:0000:0000?"

"2001:db8:0:ab00:0"

"2001:db8::ab00::"

"2001:db8:0:0:ab::"

"2001:db8:0:0:ab00::"

"D"

"There are two rules to help reduce the notation of IPv6 addresses. The first one is to omit any leading 0s (zeros) in any hextet. The second one is that a double colon (::) can replace any single, contiguous string of one or more 16-bit hextets consisting of all zeros, but the double colon (::) can only be used once within an address. If an address has more than one contiguous string of all-0 hextets, the best practice is to use the double colon (::) on the longest string. So, applying the first rule in the IPv6 address we have 2001:db8:0:0:ab00:0:0:0, and applying the second rule results in 2001:db8:0:0:ab00::"

"Which DHCPv4 message will a client send to accept an IPv4 address that is offered by a DHCP server?"

"broadcast DHCPACK"

"unicast DHCPREQUEST"

"unicast DHCPACK"

"broadcast DHCPREQUEST"

"D"

"When a DHCP client receives DHCPOFFER messages, it will send a broadcast DHCPREQUEST message for two purposes. First, it indicates to the offering DHCP server that it would like to accept the offer and bind the IP address. Second, it notifies any other responding DHCP servers that their offers are declined."

"Which statement is true about DHCP operation?"

"If the client receives several DHCPOFFER messages from different servers, it sends a unicast DHCPREQUEST message to the server from which it chooses to obtain the IP information."

"When a device that is configured to use DHCP boots, the client broadcasts a DHCPDISCOVER message to identify any available DHCP servers on the network."

"The DHCPDISCOVER message contains the IP address and subnet mask to be assigned, the IP address of the DNS server, and the IP address of the default gateway."

"A client must wait for lease expiration before it sends another DHCPREQUEST message."

"B"

"The client broadcasts a DHCPDISCOVER message to identify any available DHCP servers on the network. A DHCP server replies with a DHCPOFFER message. This message offers to the client a lease that contains such information as the IP address and subnet mask to be assigned, the IP address of the DNS server, and the IP address of the default gateway. After the client receives the lease, the received information must be renewed through another DHCPREQUEST message prior to the lease expiration."

"What is the destination IP address when an IPv4 host sends a DHCPDISCOVER message?"

"224.0.0.1"

"255.255.255.255"

"0.0.0.0"

"192.168.1.1"

"B"

"Because a DHCP client does not have a valid IPv4 address, it must use a broadcast IP address of 255.255.255.255 as the destination address to communicate with the DHCP server. The DHCPDISCOVER message sent by the client is the first message sent in order to make initial contact with a DHCP server."

"What is the result if the default gateway address is misconfigured on a PC?"

"The PC can communicate with devices both in remote networks and in the same network."

"The PC can communicate with devices in remote networks but not with those in the same network."

"The PC cannot communicate with any devices."

"The PC can communicate with devices in the same network but not with those in remote networks."

"D"

"The default gateway for a PC is the closest networking device that can forward traffic to other networks. If a PC has an incorrect or nonexistent default gateway address, it will not be able to communicate with devices in remote networks. However, communication would occur between devices in the same network with or without a default gateway."

"Which type of address can be shared through NAT to enable home network devices to send and receive data over the internet?"

"private IPv6 address"

"registered MAC address"

"broadcast MAC address"

"registered public IP address"

"D"

"Network address translation (NAT) implemented on the home network router enables privately addressed devices to share a registered public IP address that can be routed over the internet."

"When a LAN is connected to the internet using a wireless router, how do devices on the LAN communicate on the internet using NAT?"

"Each LAN must select a single client device from the wireless router settings that can communicate to the internet via NAT."

"All devices must share the single public IPv4 address assigned to the wireless router in order to communicate to the internet via NAT."

"Only a small group of high priority client devices can be chosen by the wireless router to communicate to the internet using NAT."

"Each device must wait to receive a token from the wireless router in order to communicate to the internet via NAT."

"B"

"Network Address Translation (NAT) is a technology that operates on a wireless router and allows all LAN hosts to share the single internet routable address configured on the external interface of the wireless router. All LAN hosts can communicate at the same time using this single internet assigned IP address."

"A home network is using NAT on the router connecting it to the internet. The PCs on the home network receive private IP addresses through DHCP. When a PC sends a packet to a web server on the internet, what is the source IP address in the packet header when it arrives at the web server?"

"the broadcast IP address of the external network connecting to the ISP"

"a registered public IP address assigned to the external router interface"

"the private IP address assigned to the PC through DHCP"

"a registered public IP address statically configured on the PC"

"B"

"On a home router, NAT converts the source address in the IP packet from the internal private IP address to a registered public IP address assigned to the external interface on the router before sending it out over the internet."

"A network administrator investigates a user problem. The user can reach hosts on the same network, but is unable to communicate to remote networks.The network administrator tries to ping the gateway address configured on the host device and is unsuccessful. What is the most likely cause of the problem?"

"The address of the remote device is incorrect. "

"The default gateway address is incorrect. "

"The IP address of the user is incorrectly configured."

"TCP/IP is not installed on the host device. "

"B"

"The default gateway address is used to forward packets to remote networks. The IP address of the host must be correct because the user can reach other hosts on the same network. The TCP/IP protocol stack is correct because of verified communication to hosts on the same network. The end device could be incorrectly configured, but the most likely cause of the issue is a wrong address for the default gateway."

"A host needs to reach another host on a remote network, but the ARP cache has no mapping entries. To what destination address will the host send an ARP request?"

"the unicast IP address of the remote host"

"the broadcast MAC address"

"the subnet broadcast IP address"

"the unicast MAC address of the remote host"

"B"

"ARP requests are sent when a host does not have an IP to MAC mapping for a destination in the ARP cache. ARP requests are sent to the Ethernet broadcast of FF:FF:FF:FF:FF:FF. In this example because the address of the remote host is unknown, an ARP request is sent to the Ethernet broadcast to resolve the MAC address of the default gateway that is used to reach the remote host."

"What is the purpose of ARP in an IPv4 network?"

"to forward data onward based on the destination IP address"

"to build the MAC address table in a switch from the information that is gathered"

"to forward data onward based on the destination MAC address."

"to obtain a specific MAC address when an IP address is known"

"D"

"ARP performs two functions:– To obtain a specific MAC address when an IP address is known, by broadcasting an ARP request message to all devices on a particular Ethernet network– To use the gathered information to create a viewable table of IP address to MAC address mappings"

"The ARP table in a switch maps which two types of address together?"

"Layer 2 address to a Layer 4 address"

"Layer 4 address to a Layer 2 address"

"Layer 3 address to a Layer 4 address"

"Layer 3 address to a Layer 2 address"

"D"

"The switch ARP table keeps a mapping of Layer 2 MAC addresses to Layer 3 IP addresses. These mappings can be learned by the switch dynamically through ARP or statically through manual configuration."

"What action does the ARP process take when a host needs to build a frame, but the ARP cache does not contain an address mapping?"

"The ARP process sends out an ARP request to the IPv4 broadcast address to discover the IPv4 address of the destination device."

"The ARP process sends out an ARP request to the Ethernet broadcast address to discover the IPv4 address of the destination device."

"The ARP process sends out an ARP request to the Ethernet broadcast address to discover the MAC address of the destination device."

"The ARP process sends out an ARP request to the IPv4 broadcast address to discover the MAC address of the destination device."

"C"

"The address resolution protocol (ARP) maintains a cache of MAC to IPv4 address mappings on the local computer. If there is no mapping in the cache for a specific IPv4 address, then the ARP process sends an Ethernet broadcast on the local link in an attempt to resolve the destination IPv4 address to a MAC address."

"Which protocol is used by a computer to find the MAC address of the default gateway on an Ethernet network?"

"DHCP"

"ARP"

"UDP"

"TCP"

"B"

"TCP provides reliable delivery of data. UDP provides unreliable delivery of data. DHCP is used for the automatic assignment of IP addresses. ARP is used to discover the MAC address of a device on the Ethernet network."

"When a router receives a packet, what information must be examined in order for the packet to be forwarded to a remote destination?"

"source IP address"

"source MAC address"

"destination MAC address"

"destination IP address"

"D"

"When a router receives a packet, it examines the destination address of the packet and uses the routing table to search for the best path to that network."

"Which portion of the network layer address does a router use to forward packets?"

"broadcast address"

"host portion"

"network portion"

"gateway address"

"C"

"There are two parts to an a network layer address, the network and host portions. Routers are not concerned about delivering packets to hosts. Routers are concerned with delivering packets to the network that a destination host is a member of."

"Why is it important for the router to maintain an accurate routing table?"

"to prevent broadcasts from occurring on the LAN"

"to determine the best path to reach the destination network"

"to provide Layer 2 addressing information for the next hop"

"to identify all of the routers in a large network"

"B"

"Routers use routing tables to store information. Routing tables contain the addresses of networks and the best path to reach those networks."

"What information is used by TCP to reassemble and reorder received segments?"

"acknowledgment numbers"

"port numbers"

"fragment numbers"

"sequence numbers"

"D"

"At the transport layer, TCP uses the sequence numbers in the header of each TCP segment to reassemble the segments into the correct order."

"A PC user issues the netstat command without any options. What is displayed as the result of this command?"

"a historical list of successful pings that have been sent"

"a local routing table"

"a network connection and usage report"

"a list of all established active TCP connections"

"D"

"When used by itself (without any options), the netstat command will display all the active TCP connections that are available."

"Which action is performed by a client when establishing communication with a server via the use of UDP at the transport layer?"

"The client sets the window size for the session."

"The client sends a synchronization segment to begin the session."

"The client sends an ISN to the server to start the 3-way handshake."

"The client randomly selects a source port number."

"D"

"Because a session does not have to be established for UDP, the client selects a random source port to begin a connection. The random port number selected is inserted into the source port field of the UDP header."

"A destination PC receives an email message with the sequence numbers on packets out of order. Which layer of the TCP/IP model is responsible for reassembling the packets of the message in the correct order?"

"transport"

"network access"

"application"

"internet"

"A"

"The transport layer of the TCP/IP model is responsible for ensuring that all packets in a message are received, reassembling the message in the correct order after all packets are received, and identifying which applications are sending and receiving network data."

"A client device has initiated a secure HTTP request to a web browser. Which well-known port address number is associated with the destination address?"

"404"

"80"

"443"

"110"

"C"

"Port numbers are used in TCP and UDP communications to differentiate between the various services running on a device. The well-known port number used by HTTPs is port 443."

"What type of applications are best suited for using UDP?"

"applications that are sensitive to delay"

"applications that are sensitive to packet loss"

"applications that need reliable delivery"

"applications that require retransmission of lost segments"

"A"

"UDP is not a connection-oriented protocol and does not provide retransmission, sequencing, or flow control mechanisms. It provides basic transport layer functions with a much lower overhead than TCP. Lower overhead makes UDP suitable for applications which are sensitive to delay."

"Which number or set of numbers represents a socket?"

"01-23-45-67-89-AB"

"192.168.1.1:80"

"10.1.1.15"

"21"

"B"

"A socket is defined by the combination of an IP address and a port number, and uniquely identifies a particular communication."

"A new employee is attempting to configure a cell phone to connect to the email server of the company. Which port number should be selected when using the IMAP4 protocol to access email messages stored on the local server?"

"69"

"110"

"143"

"25"

"C"

"The IMAP4 protocol uses the TCP protocol with port 143 for accessing emails stored on a local server."

"What is a function of the tracert command that differs from the ping command when they are used on a workstation?"

"The tracert command sends one ICMP message to each hop in the path."

"The tracert command reaches the destination faster."

"The tracert command is used to test the connectivity between two devices."

"The tracert command shows the information of routers in the path."

"D"

"The tracert command sends three pings to each hop (router) in the path toward the destination and displays the domain name and IP address of hops from their responses. Because tracert uses the ping command, the travel time is the same as a standalone ping command. The primary function of a standalone ping command is to test the connectivity between two hosts."

"A technician is troubleshooting a network where it is suspected that a defective node in the network path is causing packets to be dropped. The technician only has the IP address of the end point device and does not have any details of the intermediate devices. What command can the technician use to identify the faulty node?"

"ping"

"ipconfig /displaydns"

"ipconfig /flushdns"

"tracert"

"D"

"The ping command is used to verify connectivity to a device,the commands ipconfig /flushdns will cause the adapter to flush the DNS cache, while ipconfig / displaydns will result in the display of the DNS information in the cache."

"Which statement describes the use of the ping command?"

"The ping command tests end-to-end connectivity between two devices."

"The ping command can be used to determine the exact location of the problem when troubleshooting reachability issues."

"The ping command shows current Layer 4 sessions."

"The ping command can be used to test reachability using the physical address of the device."

"A"

"The ping command is used to test end-to-end connectivity between the source and destination IP address. It measures the time it takes a test message to make a round trip between the two end points. However, if the message does not reach the destination, or in the case of delays, there is no way to determine where the problem is located."

"A computer has been assigned an IP address of 169.254.33.16. What command initiates the process of requesting a new IP address?"

"ipconfig /release"

"nslookup"

"tracert"

"net computer"

"A"

"Forcing a PC to release its DHCP binding allows a new DHCP request operation to occur. The net, tracert, and nslookup commands do not have any effect on DHCP configurations."

"Which statement describes the use of powerline networking technology?"

"New “smart” electrical cabling is used to extend an existing home LAN."

"A device connects to an existing home LAN using an adapter and an existing electrical outlet."

"A home LAN is installed without the use of physical cabling."

"Wireless access points use powerline adapters to distribute data through the home LAN."

"B"

"Powerline networking adds the ability to connect a device to the network using an adapter wherever there is an electrical outlet. The network uses existing electrical wiring to send data. It is not a replacement for physical cabling, but it can add functionality in places where wireless access points cannot be used or cannot reach devices."

"Which wireless RF band do IEEE 802.11b/g devices use?"

"5 GHz"

"60 GHz"

"2.4 GHz"

"900 MHz"

"C"

"900 MHz is an FCC wireless technology that was used before development of the 802.11 standards. 900 MHz devices have a larger coverage range than the higher frequencies have and do not require line of sight between devices. 802.11b/g/n/ad devices all operate at 2.4 GHz. 802.11a/n/ac/ad devices operate at 5 GHz, and 802.11ad devices operate at 60 GHz."

"What is a disadvantage of deploying a peer-to-peer network model?"

"difficulty of setup"

"high degree of complexity"

"high cost"

"lack of centralized administration"

"D"

"The simplest peer-to-peer network consists of two computers that are directly connected to each other through the use of a wired or wireless connection. The primary disadvantages of a peer-to-peer network are its lack of central administration, minimal security, and its lack of scalability."

"Which type of device provides an Internet connection through the use of a phone jack?"

"cable modem"

"Wi-Fi AP"

"satellite modem"

"DSL modem"

"D"

"SL technology uses the existing telephone network. For that reason, a DSL modem commonly has an RJ-11 phone"

"A traveling sales representative uses a cell phone to interact with the home office and customers, track samples, make sales calls, log mileage, and upload/download data while at a hotel. Which internet connectivity method would be a preferred method to use on the mobile device due to the low cost?"

"DSL"

"cellular"

"cable"

"Wi-Fi"

"D"

"Mobile devices typically use either the cellular network or a Wi-Fi network to connect to the internet. The Wi-Fi connection is preferred because it uses less battery power and is free in many places."

"A user is configuring a wireless access point and wants to prevent any neighbors from discovering the network. What action does the user need to take?"

"Configure DMZ settings."

"Configure a DNS server."

"Enable WPA encryption."

"Disable SSID broadcast."

"D"

"Disabling SSID broadcast prevents the access point from announcing the name of the network. Enabling WPA encryption, configuring DMZ settings, and configuring a DNS server will accomplish different tasks, but the name of the network will still be announced."

"A tourist is traveling through the countryside and needs to connect to the internet from a laptop. However, the laptop only has Wi-Fi and Ethernet connections. The tourist has a smartphone with 3G/4G connectivity. What can the tourist do to allow the laptop to connect to the internet?"

"Use an Ethernet cable to connect the smartphone to the laptop."

"Use the smartphone to access the internet through a satellite connection and then share that connection with the laptop."

"Enable tethering and create a hotspot."

"Use the smartphone to access web pages and then pass the web pages to the laptop."

"C"

"Many cell phones have the ability to connect to other devices through a feature called tethering. The connection can be made using Wi-Fi, Bluetooth, or a USB cable. Once a device is connected, it is able to use the cellular connection of the phone to access the internet. When a cellular phone allows Wi-Fi devices to connect and use the mobile data network, this is called a hotspot."

"What layer is responsible for routing messages through an internetwork in the TCP/IP model?"

"network access"

"internet"

"transport"

"session"

"B"

"The TCP/IP model consists of four layers: application, transport, internet, and network access. Of these four layers, it is the internet layer that is responsible for routing messages. The session layer is not part of the TCP/IP model but is rather part of the OSI model."

"What process involves placing one message format inside of another message format?"

"flow control"

"segmentation"

"encoding"

"encapsulation"

"D"

"When a message is placed inside of another message, this is known as encapsulation. On networks, encapsulation takes place when one protocol data unit is carried inside of the data field of the next lower protocol data unit."

"A cable installation company is trying to convince a customer to use fiber-optic cabling instead of copper cables for a particular job. What is one advantage of using fiber-optic cabling compared to copper cabling?"

"The installation skills required for fiber-optic cabling are lower."

"Fiber-optic cabling is completely immune to EMI and RFI."

"Fiber-optic cabling can transmit signals without attenuation."

"The cost of fiber-optic connectors is lower."

"B"

"When comparing UTP cabling with fiber-optic cabling, note the following: fiber-optic connectors have higher costs, technician installation skills required are higher, fiber bandwidth supported is higher, and fiber-optic cabling is immune to RFI and EMI, and can transmit signals with less attenuation."

"What data encoding technology is used in copper cables?"

"modulation of light rays"

"pulses of light"

"electrical pulses"

"modulation of specific frequencies of electromagnetic waves"

"C"

"Data is transmitted across a network on media. Modern networks primarily use three types of media to interconnect devices:Metal wires within cables (copper cable, such as twisted-pair and coaxial cable) – Data is encoded into electrical impulses.Glass or plastic fibers within cables (fiber-optic cable) – Data is encoded into pulses of light.Wireless transmission – Data is encoded via modulation of specific frequencies of electromagnetic waves."

"What information is added to the switch table from incoming frames?"

"source MAC address and incoming port number"

"destination IP address and incoming port number"

"destination MAC address and incoming port number"

"source IP address and incoming port number"

"A"

"A switch “learns” or builds the MAC address table based on the source MAC address as a frame comes into the switch. A switch forwards the frame onward based on the destination MAC address."

"At which layer of the OSI model would a logical address be added during encapsulation?"

"transport layer"

"physical layer"

"network layer"

"data link layer"

"C"

"Logical addresses, also known as IP addresses, are added at the network layer. Physical addresses are edded at the data link layer. Port addresses are added at the transport layer. No addresses are added at the physical layer."

"Which type of network model describes the functions that must be completed at a particular layer, but does not specify exactly how each protocol should work?"

"protocol model"

"reference model"

"TCP/IP model"

"hierarchical design model"

"B"

"There are two common types of network communication models:Protocol model – This model closely matches the structure of a particular protocol suite and describes the functions that occur at each layer of protocols within the suite. The TCP/IP model is an example of a protocol model.Reference model – The primary purpose is to aid in a clearer understanding of the functions and processes necessary for network communications.This type of model does not specify exactly how a function should be accomplished. The OSI model is an example of a reference model."

"Which scenario is suitable for deploying twisted-pair cables?"

"to connect PC workstations in an office"

"to connect network devices in backbone networks"

"to connect a TV set to the wall plug at home"

"to connect data centers with high bandwidth requirements over long distances"

"A"

"Ethernet technology generally uses twisted-pair cables to interconnect devices. Because Ethernet is the foundation for most local networks, twisted-pair is the most commonly used type of network cabling for connecting office computers."

"A company uses DHCP servers to dynamically assign IPv4 addresses to employee workstations. The address lease duration is set as 5 days. An employee returns to the office after an absence of one week. When the employee boots the workstation, it sends a message to obtain an IP address. Which Layer 2 and Layer 3 destination addresses will the message contain?"

"MAC address of the DHCP server and 255.255.255.255"

"FF-FF-FF-FF-FF-FF and 255.255.255.255"

"both MAC and IPv4 addresses of the DHCP server"

"FF-FF-FF-FF-FF-FF and IPv4 address of the DHCP server"

"B"

"When the lease of a dynamically assigned IPv4 address has expired, a workstation will send a DHCPDISCOVER message to start the process of obtaining a valid IP address. Because the workstation does not know the addresses of DHCP servers, it sends the message via broadcast, with destination addresses of FF-FF-FF-FF-FF-FF and 255.255.255.255."

"Which number grouping is a valid IPv6 address?"

"12aa::1298:1200::129b"

"1234:1230::1238::1299:1000::"

"2001:0db8:3c55:0015:1010:0000:abcd:ff13"

"1b10::1100::2001::2900::ab11::1102::0000::2900"

"C"

"An IPv6 address is made up of 128 bits represented in hexadecimal numbers.There are two rules that help reduce the number of digits needed to represent an IPv6 address.Rule 1 – Omit leading zeros in any 16-bit section.Rule 2 – Replace any single group of consecutive zeros with a double colon (::). This can only be used once within an IPv6 address."

"Open the PT activity. Perform the tasks in the activity instructions and then answer the question. Which IP address should be used as the default gateway address on PC0?"

"192.168.2.10"

"192.168.1.1"

"192.168.2.5"

"192.168.1.2"

"A"

"The default gateway address identifies a network device through which end user devices on the LAN can communicate with hosts on remote networks. The default gateway is usually the router interface attached to the LAN."

"A network administrator has a multi-floor LAN to monitor and maintain. Through careful monitoring, the administrator has noticed a large amount of broadcast traffic slowing the network. Which device would you use to best solve this problem?"

"server"

"router"

"switch"

"host"

"B"

"All hosts within a single LAN belong to one broadcast domain. As the number of hosts increase, it could cause more traffic on the segment and may slow network performance. To solve the performance issue, a router would be the device used to segment the single LAN into multiple LANs."

"An employee is having connectivity issues. Why might a network technician try to ping the default gateway from the employee laptop?"

"to verify that the SVI interface on the switch is configured correctly"

"to determine if the laptop address is included in the DNS server"

"to verify connectivity with the device that provides access to remote networks"

"to verify that an IP address was provided by the DHCP server"

"C"

"The default gateway address is usually the address of the router interface. The router provides access to remote networks, so a successful ping to the default gateway would mean that the laptop is able to communicate with the router."

"Which command would a technician use to display network connections on a host computer?"

"nslookup"

"tracert"

"ipconfig"

"netstat"

"D"

"The netstat command is a network utility that can be used to display active TCP connections that are open and running on a networked host."

"How are port numbers used in the TCP/IP encapsulation process?"

"Source port and destination port numbers are randomly generated."

"Destination port numbers are assigned automatically and cannot be changed."

"If multiple conversations occur that are using the same service, the source port number is used to track the separate conversations."

"Source port numbers and destination port numbers are not necessary when UDP is the transport layer protocol being used for the communication."

"C"

"Both UDP and TCP use port numbers to provide a unique identifier for each conversation. Source port numbers are randomly generated and are used to track different conversations. Destination port numbers identify specific services by using either a default port number for the service or a port number that is assigned manually by a system administrator."