Testout Midterm

A rack's height is measured in rack units (Us). How tall is a single rack unit? 1.5 inches tall 1.25 inches tall 1.75 inches tall 2 inches tall

1.75 inches tall EXPLANATION A single rack unit (1U) is 1.75 inches tall and represents one slot in the rack.

You're configuring a network firewall to allow SMTP outbound email traffic and POP3 inbound email traffic. Which of the following TCP/IP ports should you open on the firewall? (Select two.) 21 143 443 110 25

110 25 EXPLANATION Simple Mail Transfer Protocol (SMTP) uses TCP/IP port 25. Post Office Protocol version 3 (POP3) uses TCP/IP port 110. File Transfer Protocol (FTP) uses TCP/IP port 21. Internet Message Access Protocol version 4 (IMAP4) uses TCP/IP port 143. Secure Sockets Layer (SSL) uses TCP/IP port 443.

Which of the following uses metal clips placed over plastic slots to connect individual copper wires? 110 block 100 pair 25 pair 66 block

110 block EXPLANATION A 110 block is a punch down block that uses metal clips fitted over plastic pins. To connect wires using a 110 block, place the wires in the plastic slots, attach the metal clip, and then punch down the connecting cable on the top of the clip. A 66 block uses metal pins to connect wires. Wires are placed in the pins, and pins within a row are electrically connected. 25 pair and 100 pair are cable bundles that include multiple pairs of copper wires (either 25 pairs of wires or 100 pairs of wires).

You've recently installed a new Windows server. To ensure system time accuracy, you've loaded an application that synchronizes the hardware clock on the server with an external time source on the internet. Now you must configure your network firewall to allow time synchronization traffic through. Which of the following ports are you MOST LIKELY to open on the firewall? 119 80 123 110

123 EXPLANATION TCP/IP port 123 is assigned to Network Time Protocol (NTP). NTP is used to communicate time synchronization information between systems on a network. HyperText Transfer Protocol (HTTP) uses TCP/IP port 80. HTTP is the protocol used to send requests to a web server and retrieve web pages from the web server. TCP/IP port 119 is used by the Network News Transfer Protocol (NNTP). NNTP is used to access and retrieve messages from newsgroups. TCP/IP port 110 is used by Post Office Protocol version 3 (POP3). POP3 is used to download email from mail servers.

Which port number is used by SNMP? 25 110 119 161

161 EXPLANATION Simple Network Management Protocol (SNMP) uses port 161. The other listed ports are used by the following protocols: SMTP uses port 25. POP3 uses port 110. NNTP uses port 119.

Which port does Telnet use? 23 80 25 53

23 EXPLANATION Telnet uses port 23. HyperText Transfer Protocol (HTTP) uses port 80. Simple Mail Transfer Protocol (SMTP) uses port 25. Domain Name System (DNS) uses port 53.

Rack heights vary from a few rack units to many rack units. The most common rack heights are 24U and 42U. How tall is a 24U rack? 30 inches 36 inches 48 inches 42 inches

42 inches EXPLANATION A 24U rack is 42 inches tall. A single rack unit (1U) is 1.75 inches tall and represents one slot in the rack. Rack heights vary from a few rack units to many rack units. The most common rack heights are 24U and 42U.

Multi-mode fiber is designed to operate at which of the following wavelengths? 1310 nm and 1550 nm 1300 nm and 1550 nm 850 nm and 1310 nm 850 nm and 1300 nm

850 nm and 1300 nm EXPLANATION Multi-mode fiber is designed to operate at 850 nm and 1300 nm. Single-mode fiber is optimized for 1310 nm and 1550 nm.

While viewing the status of interfaces on a Cisco switch, you see an abnormally large number of CRC errors on one interface. This interface is connected to a user's workstation that is located in a cubicle on the second floor. What could cause this to happen? A strong EMI emitter near the cable connected to that interface. Two hosts on the network with the same MAC address. An incorrect subnet mask configured on the workstation. Collisions between two or more network hosts.

A strong EMI emitter near the cable connected to that interface. EXPLANATION The most likely cause is EMI or crosstalk on the UTP cabling, which can corrupt frames transmitted on the wire and cause a CRC error. On a hub-based Ethernet network, these errors are usually caused by collisions. However, because a switch is being used in this scenario, collisions can't occur. CRC errors are almost always Layer 1 errors. Duplicate MAC addresses would result in a Layer 2 error. Incorrect protocol or IP addressing configurations result in Layer 3 errors.

Which of the following is a valid MAC address? AB.07.CF.62.16.BD FABC.875E.9BG6 95ABC2F4.ABC5.569D.43BF 145.65.254.10

AB.07.CF.62.16.BD EXPLANATION MAC addresses are comprised of 12 hexadecimal digits (ranging from 0-9 and A-F). They're typically represented as three sets of four hexadecimal digits or six sets of two hexadecimal digits, separated with periods. Regardless of the grouping and separator values, you look for 12 hex digits to determine whether a MAC address is valid.

During network transmission, data is transferred to various routers, which forward the data to the appropriate network. If the source and destination network addresses reside on the same network, which protocol is used to determine the destination IP's MAC address? UDP HTTP GET TCP ARP

ARP EXPLANATION Address Resolution Protocol (ARP) is used to determine the host's MAC address using the destination IP address. An HTTP GET requests web page information from a web server. UDP and TCP are both Transport layer protocols.

A host wants to send a message to another host that has an IP address of 115.99.80.157, but it does not know the destination device's hardware address. Which protocol can be used to discover the MAC address? IGMP ICMP DNS ARP

ARP EXPLANATION Hosts use Address Resolution Protocol (ARP) to discover a host's hardware address. DNS is used to map hostnames to IP addresses. ICMP notifies routers of problems on the network and undeliverable packets. IGMP establishes multicast group memberships, which allows a computer to send a single network packet to multiple hosts on a network at the same time.

You need to replace a fiber optic cable that's connecting two switches together. You inspect the existing cable and determine that it uses LC connectors. You also notice that the cable's ferrule has a slight slant to it. Which polish grade should you use to replace the existing cable? Angled Physical Contact polish Ultra Physical Contact polish Physical Contact polish Flat Physical Contact polish

Angled Physical Contact polish EXPLANATION A slight slant to the fiber ferrule indicates an Angled Physical Contact (APC) polish. Using a non-angled connector will cause excessive insertion loss. A Physical Contact (PC) polish is polished with a slight curvature. An Ultra Physical Contact (UPC) polish uses a higher grade polish and is slightly more curved than a PC polish. A Flat Physical Contact connector has little to no curvature and suffers from the most insertion loss.

Match each networking function or device on the left with its associated OSI model layer on the right. Application layer Presentation layer Session layer Transport layer Network layer Data Link layer Physical layer

Application layer - HTTP Presentation layer - Encapsulation Session layer - Session ID number Transport layer - Port number Network layer - Router Data Link layer - Switch Physical layer - Modem EXPLANATION The following table describes how devices function at different layers of the OSI model: HTTP functions at the Application layer. Encapsulation happens at the Presentation layer. Session IDs are assigned at the Session layer. Port numbers are assigned at the Transport layer. Routers function at the Network layer. Switches function at the Data Link layer. Modems function at the Physical layer.

You're working with an older 10Base2 Ethernet network. Which of the following connector types will you MOST LIKELY encounter? ST BNC RJ11 F-type

BNC EXPLANATION A 10Base2 Ethernet network (also called a thinnet) is an older type of network that uses coaxial cables with BNC connectors for communication. F-type connectors are used for cable and satellite TV connections as well as broadband cable connections. RJ11 connectors are typically used for dial-up and DSL connections. ST connectors are used with fiber optic cables.

Match each TCP/IP layers with its function. Breaks the data into pieces. Prepares the data to be sent. Adds physical addesses. Adds logical addresses.

Breaks the data into pieces. - Transport Prepares the data to be sent. - Application Adds physical addesses. - Link Adds logical addresses. - Internet EXPLANATION The Application layer prepares data to be sent through the network. The Transport layer breaks data into pieces called segments, adding sequencing and control information. The Internet layer converts segments into packets, adding logical network and device addresses. The Link layer converts packets into frames, adding physical device addressing information and a frame check sequence footer for error detection. It also converts the frames into bits (0s and 1s) for transmission across the transmission media.

Which of the following topologies connects all devices to a trunk cable? Star Mesh Bus Ring

Bus EXPLANATION A bus topology connects all devices to a trunk cable. A ring topology connects neighboring nodes until they form a ring. A star topology uses a hub or switch to connect all network connections to a single physical location. A mesh topology exists when there are multiple paths between any two nodes on a network.

Which of the following is a valid MAC address? 73-99-12-61-15 C0-34-FF-15-01-8E 34-9A-86-1G-B3-24 83-5A-5B-0B-31-55-F1

C0-34-FF-15-01-8E EXPLANATION A MAC address is a unique identifier hard coded onto every network adapter card. A valid MAC address has a total of 12 hexadecimal numbers. Hexadecimal numbers contain the numbers 0 to 9 and the letters A to F. Valid values for each octet in a MAC address range anywhere from 00 to FF. Note that one of the answers would be a valid MAC address except it uses a G value, which is beyond the hexadecimal range.

You are making Ethernet drop cables using Cat5e cables and RJ45 connectors. You need to remove the plastic coating over the cable to expose the individual wires. Which tool should you use? Cable stripper Punch down tool Snips Crimping tool

Cable stripper EXPLANATION Use a cable stripper to remove a cable's plastic jacket or sheath. When you make drop cables or use punch down blocks, do not remove the plastic covering for individual wires. Use snips to cut cables. Use a punchdown tool to push wires into 66 or 110 blocks and cut the wires at the same time. A crimping tool is designed for RJ45 connectors to attach connectors to UTP cables.

Which of the following cable types often includes a solid plastic core that keeps the twisted pairs separated? Cat 5 Cat 3 Cat 5e Cat 6

Cat 6 EXPLANATION Cat 6 cables include a solid plastic core that keeps the twisted pairs separated and prevents the cable from being bent too tightly. Cat 3, Cat 5, and Cat 5e don't include a solid plastic core that keeps the twisted pairs separated.

What is the purpose of a frame check sequence (FCS) footer? Control information Hold segment data Checksum error detection Contain logical network addresses

Checksum error detection EXPLANATION The Link layer converts packets into frames, adding physical device addressing information and a frame check sequence footer for error detection. It also converts the frames into bits (0s and 1s) for transmission across the transmission media. Control information is added at the Transport layer. The Transport layer breaks the data into pieces called segments. The Internet layer converts the segments into packets, adding logical network and device addresses.

You've implemented a network where hosts are assigned specific roles, such as file sharing and printing roles. Other hosts access those resources, but they don't host services of their own. Which type of network do you have? Intranet Extranet Client-server Peer-to-peer

Client-server In a client-server network, hosts have specific roles. For example, some hosts are assigned server roles, which allow them to provide network resources to other hosts. Other hosts are assigned client roles, which allow them to consume network resources. In a peer-to-peer network, each host can provide network resources to other hosts or access resources located on other hosts, and each host is in charge of controlling access to those resources. An intranet is a private network that uses internet technologies. Services on an intranet are only available to hosts that are connected to the private network. An extranet is a private network that uses internet technologies, but whose resources are made available to external (but trusted) users. For example, you might create a website on a private network that only users from a partner company can access.

Which of the following tasks is associated with the Session layer? Connection establishment Data block breakdown IP address assignment Port number assignment

Connection establishment EXPLANATION Connection establishment is controlled through Session layer protocols. The Transport layer breaks down data into blocks called segments. It then appends a port number to identify which top-layer application needs to receive the data on the destination device. One very important thing that happens at the Network layer is IP address assignment.

What is the basic purpose of the OSI Physical layer? Define when devices have access to the LAN. Define how physical network devices are identified on a network. Coordinate rules for sending and receiving electrical signals. Maintain a list of known networks and neighboring routers.

Coordinate rules for sending and receiving electrical signals. EXPLANATION The OSI Physical layer sets standards for sending and receiving electrical signals between devices. The Data Link layer defines how physical network devices are identified on a network and when devices have access to the LAN. The Network layer maintains a list of known networks and neighboring routers.

You've decided to implement Gigabit Ethernet on your network; each switch port is connected to a single device. Following the installation, you find one device connected to a switch that's only running at 100 Mbps. Which of the following is MOST LIKELY the cause? Collisions Impedance A short Crosstalk

Crosstalk EXPLANATION Crosstalk is interference caused by signals within a twisted pairs of wires. Crosstalk and other miswiring problems typically mean that a cable doesn't operate at the desired standard. Use a cable certifier to verify that the cable is properly configured to support the rated speed. A short is when the signal is received on an incorrect wire. A short typically means the cable doesn't work at all or communications are very limited and extremely slow. Collisions are eliminated when you connect a single device to each switch port. Impedance is mostly a factor in coaxial cables used for networking. Be sure to choose cables with the correct rating (50 or 75 ohm) based on the network type. Never mix cables that have different ratings.

In the OSI model, which of the following functions are performed at the Presentation layer? (Select two.) Data format specifications Data frame transmission Data encryption and compression End-to-end flow control Network services

Data format specifications Data encryption and compression EXPLANATION The Presentation layer encrypts data, changes and converts character sets, and compresses data. File formats (such as .jpg, .wmv, and .wav) are part of the Presentation layer. The Application layer provides network services. End-to-end flow control is provided by the Transport layer. Frame transmission occurs at the Physical layer.

Which of the following describes the point where the service provider's responsibility to install and maintain wiring and equipment ends and the customer's begins? Punch down block Vertical cross connect IDF Demarc

Demarc EXPLANATION When you contract with a local exchange carrier (LEC) for data or telephone services, they install a physical cable and a termination jack on your premises. The demarcation point (demarc) is the line that marks the boundary between the Telco equipment and the private network or telephone system. Typically, the LEC is responsible for all the equipment on one side of the demarc, and the customer is responsible for all the equipment on the other side of the demarc. A punch down block is a block used to connect individual copper wires together. While the demarc might terminate in a punch down block, punchdown blocks are used within other locations at the customer site. An intermediate distribution frame (IDF) is a smaller wiring distribution point within a building. IDFs are typically located on each floor directly above the main distribution frame (MDF), although additional IDFs can be added on each floor as necessary. A vertical cross connect connects the IDF to the MDF on a different floor.

You have a cable internet connection at home. The installer had connected the router near the outside wall of your house with RG6 cable. You move the cable router a distance of 50 meters using RG8 cables and special connector adapters. Which condition are you MOST LIKELY to experience? FEXT Echo EMI NEXT

Echo EXPLANATION An impedance mismatch (manifested by echo) occurs when you connect cables and devices that have a different impedance (resistance) rating. RG6 cables have a rating of 75 ohms, while RG8 cables have a rating of 50 ohms. Near-end crosstalk (NEXT) is crosstalk measured on the same end as the transmitter. Far-end crosstalk (FEXT) is crosstalk measured on the opposite end from the transmitter. Electromagnetic interference (EMI) and radio frequency interference are external signals that interfere with normal network communications.

Which of the following is the process of breaking a message into packets, adding controls and other information, and then transmitting the message through the transmission medium? Encapsulation Sequencing Transformation Segmentation

Encapsulation EXPLANATION Encapsulation is the process of breaking a message into packets, adding controls and other information, and then transmitting the message through the transmission medium. The Transport layer adds sequencing and control information. The Internet layer converts the segments into packets. Data flows down through the layers of the OSI model on the sending system and is transformed at each layer.

Which of the following functions are performed by the OSI Transport layer? (Select three.) Media access control, logical topology, and device identification Consistent data formatting between dissimilar systems End-to-end flow control Path identification and selection Reliable message delivery Data segmentation and reassembly Packet formatting for delivery through the medium

End-to-end flow control Reliable message delivery Data segmentation and reassembly EXPLANATION The Transport layer is responsible for breaking upper-layer data into segments and allowing reliable communication through end-to-end flow control, error detection, and error correction. Message transmission through a medium is performed at the Physical layer. Media access, logical topology, and device identification occur at the Data Link layer. Path identification and selection is a function of the Network layer. Data formatting is performed at the Presentation layer.

You've just signed up for a broadband home internet service that uses coaxial cabling. Which connector type will you MOST LIKELY use? BNC RJ45 F-type RJ11

F-type EXPLANATION Use an F-type connector for broadband cable connections that use coaxial cabling. Use a BNC connector for 10Base2 Ethernet networks. Use an RJ11 connector for modem connections to a phone line. Use an RJ45 connector for an Ethernet network that uses twisted pair cabling.

You are the network administrator for a small organization. Recently, you contracted with an ISP to connect your organization's network to the internet. Since doing so, it has come to your attention that an intruder has invaded your network from the internet on three separate occasions. Which type of network hardware should you implement to prevent this from happening again? Firewall Switch Hub Router

Firewall EXPLANATION A firewall's role is to provide a barrier between an organization's network and a public network, such as the internet. The firewall's job is to prevent unauthorized access to the organization's private network. To do this, the firewall examines incoming packets and determines whether they should be allowed to enter based on a set of rules defined by the network administrator. Routers offer some packet-based access control, but it is not as extensive as what a full-fledged firewall provides. Hubs are not sufficient for managing the interface between a trusted and an untrusted network. Switches use the MAC address in a frame for forwarding decisions.

Which of the following creates a visual representation of physical components along with a clearly defined set of principles and procedures? Floor plan Logical network diagram Wiring diagram Rack diagram

Floor plan EXPLANATION A floor plan creates a visual representation of physical components along with a clearly defined set of principles and procedures. A logical network diagram isn't so much about the physical layout of devices, but more of how traffic flows across the network. A rack diagram, or rack elevation, is a map of the IT equipment layout within a server rack. A wiring diagram is a map of the physical connections and physical layout of the electrical and circuit systems in a building.

Which of the following are advantages of using fiber optic cabling for a network? (Select two.) Greater cable distances without a repeater Easy to work with Immunity to electromagnetic interference Lower installation cost No special training or equipment is required

Greater cable distances without a repeater Immunity to electromagnetic interference EXPLANATION Compared to other types of cabling, fiber optic cabling allows greater cable distances without a repeater and is immune to electromagnetic interference. However, it is more costly, difficult to work with, and specialized training and equipment is required for installation.

Which of the following hardware devices regenerate a signal out of all connected ports without examining the frame or packet contents? (Select two.) Switch Router Hub Bridge Repeater

Hub Repeater EXPLANATION A hub and a repeater send received signals out of all other ports. These devices do not examine the frame or packet contents. Switches and bridges use the MAC address in a frame for forwarding decisions. A router uses the IP address in a packet for forwarding decisions.

Which of the following protocols allows hosts to exchange messages to indicate problems with packet delivery? TFTP ICMP IGMP DHCP

ICMP EXPLANATION Internet Control Message Protocol (ICMP) allows hosts to exchange messages to indicate a packet's status as it travels through a network. IGMP (Internet Group Management Protocol) establishes multicast group memberships, which allows a computer to send a single network packet to multiple hosts on a network at the same time. DHCP is used to automatically assign addresses and other configuration parameters to network hosts. TFTP (Trivial File Transfer Protocol) is often used when files need to be transferred between systems quickly.

What role does ARP play in the routing process? If a router does not know a destination device's MAC address, it sends an ARP broadcast containing the destination device's IP address and requesting its MAC address. If a router knows a destination host's MAC and IP address, it sends an ARP request to update the other routers' routing tables. ARP does not play any role in the routing process. Switches use ARP to map IP addresses to MAC addresses in collision domains. If a router does not know a destination device's IP address, it sends an ARP broadcast containing the destination device's MAC address and requesting its IP address.

If a router does not know a destination device's MAC address, it sends an ARP broadcast containing the destination device's IP address and requesting its MAC address. EXPLANATION ARP (Address Resolution Protocol) resolves IP addresses into MAC addresses. Routers and other network devices use ARP when their routing tables don't contain the MAC addresses of devices on the local LAN that they need to forward frames to.

In the OSI model, which of the following functions are performed at the Application layer? (Select two.) Standard setting for sending and receiving signals. Integration of network functionality into the host operating system. Enabling of communication between network clients and services. Communication setup, maintenance, and teardown. Device control for data transmission rates.

Integration of network functionality into the host operating system. Enabling of communication between network clients and services. EXPLANATION The Application layer enables network services and integrates network functionality into the host operating system. Applications actually run above the OSI Application layer. The setup, maintenance, and teardown of communication happens at the Session layer. The Data Link layer controls the rate of data transmission between hosts (flow control). The Physical layer sets standards for sending and receiving electrical signals between devices.

Which of the following BEST describes how a switch functions? It connects multiple cable segments (or devices) and forwards frames to the appropriate segment. It connects multiple cable segments (or devices) and broadcasts frames to all of its ports. It connects multiple segments of different architectures. It translates frames and broadcasts them to all of its ports. It connects multiple segments of different architectures. It translates frames and forwards them to the appropriate segment.

It connects multiple cable segments (or devices) and forwards frames to the appropriate segment. EXPLANATION Switches have multiple ports and can connect multiple segments or devices. The switch forwards frames to the appropriate port. They function similarly to a hub, except instead of sending packets to all ports, switches send packets only to the destination computer's port. A bridge is a device that connects two (or more) media segments on the same subnet. It filters traffic between both segments based on the MAC address in the frame.

Which of the following statements accurately describe how a modem works? (Select two.) It modulates digital data from a telephone network into analog data that a PC can use. It demodulates analog data from a telephone network into digital PC data. It demodulates analog PC data into digital data that can be transmitted through a telephone network. It communicates over a telephone network using digital signals. It modulates digital data from a PC into analog data and transmits it on a telephone network.

It demodulates analog data from a telephone network into digital PC data. It modulates digital data from a PC into analog data and transmits it on a telephone network. EXPLANATION Modem is shorthand for modulator/demodulator. A modem's job is to convert (or modulate) digital data from a PC into analog telephone signals and transmit them through a telephone network. Modems also receive analog data from the telephone network and convert (or demodulate) it into digital PC data.

Which of the following are characteristics of a coaxial network cable? (Select two.) The conductors within the cable are twisted around each other to eliminate crosstalk. It has a conductor made from copper in its center. It is composed of four pairs of 22-gauge copper wire. It uses two concentric metallic conductors. It uses RJ45 connectors.

It has a conductor made from copper in its center. It uses two concentric metallic conductors. EXPLANATION Coaxial cable is composed of a central copper conductor surrounded by an insulator, which is then surrounded by a second metallic mesh conductor. The name coaxial is derived from the fact that both of these conductors share a common axis. Both ends of a coaxial cable must be terminated. Twisted pair is composed of four pairs of 22-gauge copper wire. The wires are twisted to reduce crosstalk, and they use RJ45 connectors.

Which of the following are true about a MAC address? (Select two.) It is a 48-bit address. It is a 64-bit address. It is typically represented by octets of decimal numbers between 0-255. It is typically represented by hexadecimal numbers. It is a 32-bit address.

It is a 48-bit address. It is typically represented by hexadecimal numbers. EXPLANATION A MAC address identifies a network adapter's physical address. It's a 12-digit (48-bit) hexadecimal number with each number ranging from 0-9 or A-F. The address is often written as 00-B0-D0-06-BC-AC or 00B0.D006.BCAC. However, dashes, periods, and colons can be used to divide it as well. An IPv4 address is 32 bits and uses octets of decimal numbers between 0-255. An IPv6 address is a 64-bit address that uses 32 hexadecimal numbers.

Which of the following is true about single-mode fiber optic network cabling? Its central core is smaller than the standard multi-mode fiber optic cabling core. It's optimized for 850 nm and 1300 nm light sources. It's less expensive than multi-mode fiber optic cabling. It has shorter segment lengths than multi-mode fiber optic cabling.

Its central core is smaller than the standard multi-mode fiber optic cabling core. EXPLANATION Single-mode fiber optic cabling provides one path (or mode) for light to travel. It supports longer transmission distances than multi-mode fiber optic cabling, and it's also more expensive. Single-mode cabling also has a central core that's much smaller than the standard multi-mode fiber optic cabling core. Single-mode fiber cabling is optimized for 1310 nanometer (nm) and 1550 nm light sources.

Which recommendation should you follow while using 110 blocks for connecting Cat5 and higher data cables? Connect wires using the T568B standard. Connect wires using the T568A standard. Use C-5 connectors. Keep wire pairs twisted up to within one half of an inch of the connector.

Keep wire pairs twisted up to within one half of an inch of the connector. EXPLANATION When you use Cat5 (or higher) wiring, preserve the twists in each wire pair to within one half of an inch of the connecting block. Use C-4 connectors to connect four pairs of wires. When connecting data wires on a 110 block, you typically connect wires in the following order: White wire with a blue stripe followed by the solid blue wire. White wire with an orange stripe followed by the solid orange wire. White wire with a green stripe followed by the solid green wire. White wire with a brown stripe followed by the solid brown wire. T568A and T568B are used to connect wires within an RJ45 connector when making drop cables.

At which OSI model layer does a media converter operate? Layer 1 Layer 2 Layer 3 Layer 4

Layer 1 EXPLANATION A media converter operates at Layer 1 of the OSI model, which is the Physical layer. The media converter translates frames into bits and transmits them on the transmission medium. At Layer 2, the MAC address is added to make the data into a frame. At Layer 3, the IP address is added to the packet. At Layer 4, the port and socket number are assigned.

Workstation3 has started communicating with Workstation2. It sends a frame to the default gateway. Identify the Layer 2 and Layer 3 addresses used by the Cisco 2600 router to forward the data to Workstation2 by dragging the corresponding address from the list on the left to its location on the right. Layer 2 source address Layer 3 source address Layer 2 destination address Layer 3 destination address

Layer 2 source address - 000b5f2a2222 Layer 3 source address - 192.168.11.11 Layer 2 destination address - 080046987654 Layer 3 destination address - 192.168.10.12 EXPLANATION The Cisco 2600 router is the default gateway. When it receives a frame from Workstation3, it examines the Layer 3 address in the packet to locate the destination device. Then it creates a new frame and modifies the source and destination Layer 2 addresses (MAC addresses) as follows: The source Layer 2 address is its own MAC address on the same segment as the destination device, which is 000b5f2a222. The destination Layer 2 address is the MAC address of the destination device, which is 080046987654. The source and destination Layer 3 addresses (IP addresses) do not change. The source IP address is the IP address of Workstation3, which is 192.168.11.11. The destination IP address is the IP address of Workstation2, which is 192.168.10.12.

Workstation2 needs to send data to Workstation3. Identify the Layer 2 and Layer 3 addresses Workstation2 will use to send the data by dragging the corresponding address from the list on the left to its location on the right. Layer 2 source address Layer 3 source address Layer 2 destination address Layer 3 destination address

Layer 2 source address - 080046987654 Layer 3 source address - 192.168.10.12 Layer 2 destination address - 000b5f2a2222 Layer 3 destination address - 192.168.11.11 EXPLANATION Workstation2 will use the following addresses to send the data: The source Layer 2 address is its own MAC address, which is 080046987654. The source Layer 3 address is its own IP address, which is 192.168.10.12. The destination Layer 2 address is the MAC address of the default gateway router, which is 000b5f2a2222. The MAC address is the address of the interface connected to the same subnet as Workstation2. The destination Layer 3 address is the IP address of the destination device (Workstation3), which is 192.168.11.11.

Which of the following features does UDP provide? (Select two.) Low overhead Connectionless datagram services Packet acknowledgement Data packet sequencing Lost packet retransmission

Low overhead Connectionless datagram services EXPLANATION UDP is a connectionless protocol used by applications that need low overhead and don't require guaranteed delivery. TCP provides data packet sequencing, packet acknowledgement, and lost packet retransmission.

Which of the following terms identifies the wiring closet in the basement or ground floor that typically includes the demarcation point? Horizontal cross connect 110 block IDF MDF

MDF EXPLANATION The main distribution frame (MDF) is the main wiring point for a building. The MDF is typically located on the bottom floor or basement. The LEC typically installs the demarc to the MDF. An intermediate distribution frame (IDF) is a smaller wiring distribution point within a building. IDFs are typically located on each floor directly above the MDF, but you can place additional IDFs on each floor as necessary. A horizontal cross connect joins wiring closets on the same floor. A smart jack is a special loopback plug installed at the demarcation point for a WAN service. Technicians at the central office can send diagnostic commands to the smart plug to test connectivity between the central office and the demarc. Use 66 and 110 blocks to connect individual wires within a wiring closet.

Which of the following connectors are used with fiber optic cables and include both cables in a single connector? (Select two.) MTRJ ST LC SC BNC

MTRJ LC EXPLANATION LC and MTRJ connectors have both fiber optic cables in a single connector. ST and SC connectors hold a single strand of fiber optic cabling. A cable using either one has two connectors on each end. A BNC connector is used with coaxial cable.

You have a server that has a 100BaseFX network interface card you need to connect to a switch. The switch only has 100BaseTX switch ports. Which device should you use? Hub Media converter Repeater Bridge

Media converter EXPLANATION Use a media converter to convert from one media type to another within the same architecture. Use a bridge to connect two devices that use different network architectures. For example, you can use a bridge to connect a wired network to wireless clients. A hub or repeater connects devices using the same media type.

Your manager has asked you to implement a network infrastructure that will accommodate failed connections. Which of the following network topologies provides redundancy for a failed link? Mesh Star Bus Ring

Mesh EXPLANATION In a mesh topology, each network device is interconnected with all other network nodes. This creates multiple data paths. If a link fails, the data has an alternate route to its destination. A star topology connects network devices to the network with a single patch cable. A patch cable failure makes the connected device unavailable. A bus topology has a single point of failure. If there's a break on the network medium, the network becomes unavailable. A single break on a physical ring topology disables the network.

You have a network that uses a logical bus topology. How do messages travel through the network? Messages are sent to a central device that forwards them to the destination devices. Messages are broadcast to all devices connected to the network. Messages are sent directly to the correct destination device. Messages travel from one device to the next until they reach the destination device.

Messages are broadcast to all devices connected to the network. Messages sent using a physical bus topology are broadcast to all devices on the network. The device in the middle of a star topology, which is typically a hub, receives the message and forwards it on to all other devices. In a ring topology, messages travel from one device to the next until they reach the destination device.

You have a network that uses a logical ring topology. How do messages travel through the network? Messages are sent to a central device that forwards them to the destination devices. Messages travel from one device to the next until they reach the destination device. Messages are sent directly to the destination device only. Messages are sent to all devices connected to the network.

Messages travel from one device to the next until they reach the destination device. EXPLANATION In a logical ring topology, messages travel to each device in turn. If the message isn't intended for that device, the message is forwarded to the next device on the network. Messages sent using a physical bus topology are broadcast to all devices on the network. The device in the middle of the star topology, which is typically a hub, receives the message and forwards it on to all other devices.

Which of the following geographic network types is typically managed by a city as a public utility? Personal area network (PAN) Wide area network (WAN) Metropolitan area network (MAN) Local area network (LAN)

Metropolitan area network (MAN) A metropolitan area network (MAN) is a network that can cover an entire city. A city typically owns and manages a MAN as a public utility. A PAN is a small network for communication between personal devices. A LAN is contained to an office and managed by a business. A WAN is a collection of LANs that are connected together to form a large internetwork. WAN connections are typically managed by an ISP.

You want to measure the voltage, amps, and ohms of various devices. Which tool should you use? Toner probe Certifier Multimeter Voltage event recorder

Multimeter EXPLANATION A multimeter is a device that tests various electrical properties. For example, most multimeters can measure: AC and DC voltage Current (amps) Resistance (ohms) Capacitance Frequency A voltage event recorder tracks voltage conditions on a power line. Basic recorders keep track of the occurrence of under- or over-voltage conditions, while more advanced devices track conditions over time and create a graph, saving data from a program running on a computer. A toner probe is two devices used to trace the end of a wire from a known endpoint onto the termination point in the wiring closet. A cable certifier is a multi-function tool that verifies or validates that a cable or an installation meets the requirements for a specific architectural implementation.

You have a large TCP/IP network and want to keep a host's real-time clock synchronized. Which protocol should you use? NTP SMTP SNMP FTP

NTP EXPLANATION Network Time Protocol (NTP) keeps computers' clocks synchronized. SMTP is used to send mail between email servers. SNMP lets network administrators set up alerts to monitor the state of a network. FTP (File Transfer Protocol) provides a generic method for transferring files.

At which OSI layer does a router operate to forward network messages? Data Link Transport Network Physical

Network EXPLANATION A router uses the logical network address specified at the Network layer to forward messages to the appropriate LAN segment. A bridge, on the other hand, uses the MAC address and works at the Data Link layer.

Which network component connects a device to transmission media and allows the device to send and receive messages? Client Network interface card Protocol Server

Network interface card EXPLANATION A network interface card (NIC) allows a device to send and receive messages over a transmission media. A client doesn't provide network services but instead consumes network services. Server operating systems are designed to do one thing, and that's to provide network resources. Protocols are rules or standards that describe how hosts communicate and exchange data.

You're installing network wiring for a new Ethernet network at your company's main office building. The project specifications call for Cat 5e UTP network cabling and RJ45 wall jacks. Near the end of the project, you run out of wire before the last few runs are complete. You have a spool of Cat 3 network cable in storage. Upon closer inspection, it appears very similar to the Cat 5e wiring. To finish the project, should you use the Cat 3 cabling as a substitute for the Cat 5e cabling? No. Cat 5e cabling uses a thicker copper wire than Cat 3 cabling, enabling higher data transmission rates. No. Cat 5e cabling has more twists per inch than Cat 3 cabling, reducing crosstalk and supporting higher data rates. No. The sheath surrounding Cat 5e cabling is much thicker than the Cat 3 sheath, creating an extra layer of shielding that reduces crosstalk and supports higher data rates. Yes. You can use Cat 3 cabling as a substitute for Cat 5e cabling since they're electrically identical.

No. Cat 5e cabling has more twists per inch than Cat 3 cabling, reducing crosstalk and supporting higher data rates. EXPLANATION While Cat 3 and Cat 5e cabling may appear physically similar, they're electrically different. Cat 5e cabling is twisted much more tightly than Cat 3 cabling. This reduces crosstalk and enables Cat 5e wiring to support much faster data transmission rates.

You're building a new network for a small financial services startup company. Security is paramount, so each organization within the company will have their own network segments separated by routers. Funds are limited, and you've been asked to keep costs to a minimum. You've acquired a used fiber optic switch, and you want to use it to create a fiber optic backbone that interconnects all of the routers. You've purchased several used multi-mode GBIC modules on eBay that you'll install on each router to allow them to connect to the switch. Both the switch and the GBIC modules use MTRJ connectors. You've purchased several used 1-meter, multi-mode patch cables from Amazon. But when they arrived, you noticed that they use LC connectors. Fortunately, with some force, you found that you're able to get the LC connectors on the cables to lock into the MTRJ connectors on the GBIC modules and on the switch. Will this implementation work? No. You should use a specialized backbone fiber optic switch to create a backbone network for routers. No. You should purchase patch cables that use MTRJ connectors. Yes. All of the requirements for implementing a fiber optic network have been met. No. You should use single-mode patch cables to connect a GBIC module to a switch.

No. You should purchase patch cables that use MTRJ connectors. EXPLANATION For light to pass through a fiber optic connector, the fiber within the jack must line up perfectly with the fiber in the connector. Using the wrong connector will result in misaligned fibers. This will disrupt the light signal, even if you're able to successfully lock the connector into the jack. In this scenario, you should purchase patch cables that use MT-RJ connectors.

You're building a new network for a small financial services startup company. Security is paramount, so each organization within the company will have its own network segment separated by a router. However, funds are limited, and you've been asked to keep costs to a minimum. You've acquired a used fiber optic switch, and you want to use it to create a fiber optic backbone that interconnects all of the routers. You've purchased several used single-mode GBIC modules on eBay that you'll install on each router to allow them to connect to the switch. Both the switch and the GBIC modules use MTRJ connectors. You connect each module to the switch with 1-meter multimode patch cables. Will this implementation work? No. You shouldn't use multi-mode patch cables with single-mode GBIC modules. No. You should purchase fiber optic equipment that use FC connectors. No. You shouldn't use standard fiber optic switches to create a backbone network for routers. Yes. All of the requirements for implementing a fiber optic network have been met.

No. You shouldn't use multi-mode patch cables with single-mode GBIC modules. EXPLANATION Some GBIC/SFP modules use multi-mode fiber, while others use single-mode. You must use the correct type of fiber optic cable and connector required by the specific adapter. You can't mix and match different types of cable. In this scenario, connecting a single-mode GBIC to multi-mode fiber will introduce a catastrophic signal loss of up to 99%.

You're working with an existing fiber optic installation in your building. You want to know the length of each cable that runs through the walls. Which tool should you use? Toner probe Smartjack OTDR Multimeter

OTDR EXPLANATION An optical time domain reflector (OTDR) sends light pulses on a cable to discover information about the cable. The results of this test can be used to: Estimate a wire's length. Measure a cable's impedance. Identify locations of splices and connectors on a wire. Identify shorts, open circuits, and fault locations. Use a toner probe to locate the end of a wire from a wall jack to the punchdown block. Use a multimeter to measure a device's electrical properties, such as voltage, amps, and resistance. A smartjack is a special loopback plug installed at a WAN service's demarcation point.

Your manager has asked you to implement a wired network infrastructure that will accommodate failed connections. You don't have a large budget, so you decide to provide redundancy for only a handful of critical devices. Which of the following network topologies should you implement? Bus Star Full mesh Partial mesh

Partial mesh EXPLANATION In a partial mesh topology, only some redundant paths exist. A partial mesh topology is more practical and less expensive than a full mesh topology. In a full mesh topology, every device has a point-to-point connection with every other device. This provides full redundancy, but it's expensive and impractical. A star topology connects network devices to the network with a single patch cable. A patch cable failure makes the connected device unavailable. A bus topology has a single point of failure. If there's a break in the network media, the network becomes unavailable.

Which of the following terminates individual wires from a 25-pair or 100-pair cable using female RJ45 ports? 66 block 110 block Horizontal cross connect Patch panel

Patch panel EXPLANATION A patch panel is a device that typically connects individual stranded wires into female RJ45 connectors. For example, you might connect four pairs of wires from a punch down block to a port on the patch panel. On the patch panel, you then connect drop cables (cables with RJ45 connectors) to the patch panel on one end and a computer on the other end. Use 66 and 110 blocks to connect individual wires within a wiring closet. These punch down blocks connect the individual wires together, but they do not terminate in RJ45 connectors. A horizontal cross connect connects IDFs on the same floor.

You've implemented a network where each device provides all other devices on the network with access to shared files. Which type of network do you have? Client-server Multiple access Polling Peer-to-peer

Peer-to-peer In a peer-to-peer network, each host can provide network resources to other hosts or access resources located on other hosts, and each host is in charge of controlling access to those resources. In a client/server network, hosts have specific roles. For example, some hosts are assigned server roles, which allow them to provide network resources to other hosts. Other hosts are assigned client roles, which allow them to consume network resources. Polling is a media access method where a single device grants permission to other devices to access the network. Multiple access describes a media access method where each device determines when the medium is free.

At which layer of the OSI model do hubs operate? Physical Data Link Internet Layer 3

Physical EXPLANATION Hubs operate at Layer 1, or the Physical layer of the OSI model.

Which of the following are included as part of the Data Link layer specifications? (Select two.) Digital data conversion Physical network device identification Physical topology Data transmission between hosts Cable and connector specifications

Physical network device identification Data transmission between hosts EXPLANATION The Data Link layer controls device identification on networks, as well as how messages travel through the network (the logical topology). The other functions listed here are performed by the Physical layer.

You need to terminate a Cat6 UTP cable with an RJ45 connector. Your organization's IT policy states that all cable connectors must be wired according to TIA568B standards. Drag the UTP wire on the left to the correct pin on the RJ45 connector on the right. Pin 1 Pin 2 Pin 3 Pin 4 Pin 5 Pin 6 Pin 7 Pin 8

Pin 1 - White with orange stripe Pin 2 - Solid orange Pin 3 - White with green stripe Pin 4 - Solid blue Pin 5 - White with blue stripe Pin 6 - Solid green Pin 7 - White with brown stripe Pin 8 - Solid brown EXPLANATION The T568B wiring standard specifies the following pinout for RJ45 connectors: Pin 1: White with orange stripe Pin 2: Solid orange Pin 3: White with green stripe Pin 4: Solid blue Pin 5: White with blue stripe Pin 6: Solid green Pin 7: White with brown stripe Pin 8: Solid brown

You're adding new wires in your building for some new offices. The building has a false ceiling that holds the lights and provides an air path for heating and air conditioning. You'd like to run your Ethernet cables in this area. Which type of cable must you use? Plenum-rated cable Cat 5e or Cat 6a cables Fiber optic cables STP cables

Plenum-rated cable EXPLANATION Plenum-rated cable is fire resistant and non-toxic. You must use plenum-rated cable to wire in air spaces used by heating and air conditioning systems. Cat 5e cables provide better EMI protection than Cat 5 cables, and Cat 6a cables are an improvement over Cat 6 specifications. However, neither of these qualities are a requirement for use in a ceiling area. If an area has a lot of EMI, you might consider using STP or fiber optic cables, but this isn't a requirement in a ceiling area. Typically, you can avoid EMI sources by re-routing cables.

You are preparing to attach wires in a 110 block. You want to connect the wires and trim off the excess at the same time. Which of the following should you do? (Select two.) Use a punch down tool with a straight blade. Point the cut side of the tool towards the wire end. Point the cut side of the tool toward the connected end of the wire. Use a punch down tool with a notched blade. Use the end without a cutting blade.

Point the cut side of the tool towards the wire end. Use a punch down tool with a notched blade. EXPLANATION Use a punch down tool to connect wires to a 110 or 66 block. When using a punch down tool, choose the right blade for the job: Use a notched blade for a 110 block. Use a straight blade for a 66 block. For both blade types, you can use the end without a cutting blade if you want to punch down without cutting the wire. When using the cutting blade, point the cut side of the punch down tool toward the wire's end that you want to trim.

Match each layer of the TCP/IP model on the left with the corresponding layer of the OSI model on the right. Each option on the left can be used more than once. Presentation layer Data Link layer Application layer Session layer Network layer Transport layer

Presentation layer - Application Data Link layer - Network Application layer - Application Session layer - Application Network layer - Internetwork Transport layer - Transport EXPLANATION The TCP/IP model maps to the OSI model as follows: The Application layer corresponds to the OSI model's Session, Presentation, and Application layers. The Transport layer matches the OSI model's Transport layer. The Internetwork layer is comparable to the OSI model's Network layer. The Network layer (sometimes called the Link layer) corresponds to the OSI model's Physical and Data Link layers.

Which term does the OSI model use that's different from the TCP/IP model in reference to the terms frame, packet, and segment? HTTP Session Presentation Protocol data unit (PDU)

Protocol data unit (PDU) EXPLANATION The OSI model uses the term protocol data unit (PDU) instead of the terms frame, packet, and segment. The Presentation and Session layers are Layers 5 and 6 of the OSI model, respectively, and do not correspond to the use of frame, packet, and segment in the TCP/IP model. HyperText Transfer Protocol (HTTP) is the protocol in the Application layer that supports web requests.

Which tool should you use to extend network services beyond the demarc? Punch down tool Crimper Patch panel Tone generator

Punch down tool EXPLANATION A demarc is the location where the local network ends and the telephone company's network begins. This location is usually at a punchdown block in a wiring closet. You use a punch down tool to attach wires to the punchdown block. A tone generator sends a signal on the wire. A crimping tool is used to attach connectors to wires. Patch panels permit circuits to be arranged and rearranged by plugging and unplugging respective patch cords on a mounted hardware assembly.

You have a small home network connected to the internet using an RG-6 cable. You need to move the router, but you can't find anymore RG-6 cabling. Which cable type could you use instead? Cat 3 RG-58 RG-59 Cat 5e

RG-59 EXPLANATION RG-6 has an impedance rating of 75 ohms. It's important to use coaxial cables with the same impedance rating, and only RG-59 is rated for 75 ohms. Connecting coaxial cables with Cat 3 and Cat 5e cables requires a media converter.

Which of the following connectors is used with Ethernet 100BaseTX networks? ST GG45 BNC RJ45

RJ45 EXPLANATION RJ45 connectors are used with Ethernet 100BaseTX networks. RJ11 connectors are used with phone, dial-up internet, and DSL modem connections. BNC connectors are used with coaxial cable. GG45 connectors are used with Cat 7 cables and support 10-Gbps Ethernet (10GBASE-T).

Which of the following connector types would you most likely use to connect to a T1 WAN service? RJ11 RJ45 RJ48c GG45

RJ48c EXPLANATION An RJ48c connector is similar to an RJ45 connector, but it has different pin-outs. RJ48c connectors are commonly used for T1 WAN connections. RJ45 connectors are used for Ethernet. RJ11 connectors are used for dial-up (modem) connections and some DSL connections. GG45 are used with Cat 7 cabling.

Which of the following topologies connects each device to a neighboring device? Bus Mesh Star Ring

Ring EXPLANATION In ring topologies, each device connects to a neighboring device so that a ring is formed. The bus topology connects all devices to a trunk cable. A star topology uses a hub or switch to connect all network connections to a single physical location. A mesh topology exists when there are multiple paths between any two nodes on a network.

In the OSI model, what is the primary function of the Network layer? Ensure that packets are delivered with no loss or duplication. Transmit data frames. Route messages between networks. Enable communication between network clients and services.

Route messages between networks. EXPLANATION The Network layer is responsible for routing messages between networks. The Transport layer provides a transition between the upper and lower layers of the OSI model. The Data Link layer defines how to verify that data received from the Physical layer is error free (using parity and cyclic redundancy check [CRC]).

Which of the following hardware devices links multiple networks and directs traffic between networks? Repeater Router Bridge Hub

Router EXPLANATION A router is a device that links multiple networks and directs traffic between networks. Each network linked by routers has its own unique identifier called the network number or network address. A hub and a repeater send received signals out all other ports. These devices do not examine the frame or the packet contents. Bridges learn addresses by copying the MAC address of the source device and placing it into the MAC address table.

Routing data between computers on a network requires several mappings between different addresses. Which of the following statements is true? Routers use ARP to resolve known IP addresses into MAC addresses. ICMP lets routers bypass the general network broadcast by providing a dynamic table of IP-to-MAC address mappings. Diskless workstations use ARP to ask a server for an IP address. Routers use DNS to resolve MAC addresses of diskless workstations into IP addresses based on the information contained in other routers' routing tables.

Routers use ARP to resolve known IP addresses into MAC addresses. EXPLANATION ARP lets routers resolve known IP addresses into MAC addresses by broadcasting requests to the network. DNS is used to map hostnames to IP addresses. ARP is used to map IP addresses to MAC addresses. Diskless workstations use BOOTP to discover their IP address, the server's IP address, and the boot files they should use. ICMP notifies routers of problems on the network and undeliverable packets.

You want a switch to have the ability to modify the media type the switch port supports. Which type of module might you use to make this possible? MAC SFP QSFP ARP GBIC

SFP GBIC EXPLANATION Older network adapters used an external transceiver that matched the media type. While nearly all current network adapters come with a built-in transceiver type, new devices, such as switches and routers, use transceiver modules that allow you to modify a port's media type by changing the transceiver. There are several types of transceiver modules. A GBIC (gigabit interface converter) is a large transceiver that fits in a port slot. GBICs are used for Gigabit media, including copper and fiber optic. An SFP (small form-factor pluggable) is similar to a GBIC but is smaller in size. An SFP is sometimes called a mini-GBIC. An XFP transceiver is similar in size to an SFP, but it's used for 10-gigabit networking. QSFP (a quad, or 4-channel, small form-factor pluggable) is a compact hot-pluggable transceiver that's also used for data communication applications. A Media Access Control (MAC) address is a unique identifier burned into the ROM of every Ethernet NIC. A host uses ARP to discover a device's MAC address from its IP address.

Your company has just acquired another company in the same city. You need to integrate the two email systems so that messages can be exchanged between email servers. Currently, each network uses an email package from a different vendor. Which TCP/IP protocol enables message exchange between systems? SMTP IMAP4 ICMP POP3

SMTP EXPLANATION Simple Mail Transfer Protocol (SMTP) specifies how messages are exchanged between email servers. Email clients use POP3 and IMAP4 to download email messages from email servers. ICMP (Internet Control Message Protocol) is used with ping and traceroute to communicate network information.

Which of the following connectors is used with fiber optic cables and requires that you use a twisting motion to connect it? BNC SC ST F-type

ST EXPLANATION An ST connector is used with fiber optic cables and uses a twist-type connector. Use the mnemonic Set and Twist. An SC connector is used with fiber optic cables, but you plug it in instead of twist it in. F-type and BNC connectors employ a twist to connect, but they're used with coaxial cables.

Which of the following connectors usually require polishing as part of the assembly process? (Select two.) BNC F-type RJ45 ST SC

ST SC EXPLANATION The fiber optic cable assembly process is more complex than other assemblies. It's necessary to polish the exposed fiber tip to ensure that light is passed from one cable to the next with minimal dispersion.

TCP is a connection-oriented protocol that uses a three-way handshake to establish a connection to a system port. Computer 1 sends a SYN packet to Computer 2. Which packet does Computer 2 send back? RST SYN/RST ACK SYN/ACK

SYN/ACK EXPLANATION If Computer 1 sends a SYN packet to Computer 2, Computer 2 receives the packet and sends a SYN/ACK packet to Computer 1. Computer 1 receives the SYN/ACK packet and replies back with an ACK packet, and the connection is complete. A SYN flag is used to start a connection between hosts. An ACK acknowledges the receipt of a packet. An RST resets a connection.

Which type of optical fiber is normally used to connect two buildings that are several kilometers apart? Shielded twisted pair Multi-mode fiber Coaxial cable Single-mode fiber

Single-mode fiber EXPLANATION In this scenario, you would use single-mode fiber optic cables. Fiber optic is graded as single-mode or multi-mode. Single-mode consists of a very thin singular core, which produces fewer reflections. This provides greater effective bandwidth over greater distances. Multi-mode is less costly than single-mode fiber. Multi-mode is used to transmit over shorter distances, as the rays tend to disperse as the transmission distance increases. Coaxial and shielded twisted pair are not suitable for long distances between buildings.

Which of the following cables offers the best protection against EMI? RG-6 Single-mode fiber optic Cat 5 Cat 5e

Single-mode fiber optic EXPLANATION Fiber optic cables offer the best protection against electromagnetic interference (EMI).

Users report that the internet is no longer accessible. You suspect that the line connecting your building to the internet isn't working properly. Which of the following allows the service provider to remotely test the local loop? Horizontal cross connect Smartjack Demarc extension Demarc

Smartjack EXPLANATION A smartjack is a special loopback plug installed at a WAN service's demarcation point. Technicians at the central office can send diagnostic commands to the plug to test connectivity between the central office and the demarc. The demarcation point (demarc) is the line that marks the boundary between telco equipment and the private network or telephone system. A demarc extension extends the demarcation point from its original location to another location within the building. A horizontal cross connect connects wiring closets on the same floor.

You have a small network that uses a switch to connect multiple devices. Which physical topology are you using? Star Ring Mesh Bus

Star EXPLANATION A switch creates a network with a physical star topology. The physical star topology uses a logical bus topology and sends messages to all the devices connected to the hub. A mesh topology is a series of point-to-point links between devices. A ring topology uses a central device called an MSAU. A bus topology connects all devices to a trunk cable.

You're an application developer, and you're writing a program for exchanging video files through a TCP/IP network. You need to select a transport protocol that will guarantee delivery. Which TCP/IP protocol provides this capability? TCP FTP SIP UDP

TCP EXPLANATION In this scenario, you should write the application to use Transmission Control Protocol (TCP). TCP guarantees delivery through error checking and acknowledgments. FTP provides a generic method for transferring files. It can protect access to files by requiring usernames and passwords. UDP is a host-to-host protocol like TCP, but it doesn't acknowledge that each packet was transmitted. SIP is an open-source VoIP protocol.

Which of the following network services or protocols uses TCP/IP port 69? NNTP TFTP POP3 SMTP

TFTP EXPLANATION Trivial File Transfer Protocol (TFTP) uses TCP/IP port 69. TFTP is a connectionless service for downloading files from a remote system. It's often used for downloading firmware to networking devices. Network News Transfer Protocol (NNTP) is used to access and download messages from newsgroup servers. NNTP uses TCP/IP port 119. Simple Mail Transfer Protocol (SMTP) is used to send and receive email. SMTP uses TCP/IP port 25. Post Office Protocol version 3 (POP3) is used to download email from a remote system. POP3 uses TCP/IP port 110.

Which of the following are characteristics of an LC fiber optic connector? (Select two.) They are half the size of standard connectors. They use a housing and latch system similar to an RJ45 UTP connector. They use a one-piece bayonet connecting system. They are threaded. They can be used with either fiber optic or copper cabling.

They are half the size of standard connectors. They use a housing and latch system similar to an RJ45 UTP connector. EXPLANATION LC fiber optic connectors are small, at about half the size of other fiber optic connectors. Their appearance is similar to a typical RJ45 connector used with UTP wiring. Like an RJ45 connector, an LC fiber optic connector uses a small latch to lock the connector in a jack. ST uses a one-piece bayonet connecting system.

Which of the following are characteristics of an MTRJ fiber optic connector? (Select two.) They must never be used with single-mode fiber optic cables. They use metal guide pins to ensure accurate alignment. They're called push-in-and-twist connectors. They use a keyed bayonet. They can be used with multi-mode fiber optic cables.

They use metal guide pins to ensure accurate alignment. They can be used with multi-mode fiber optic cables. EXPLANATION MTRJ connectors can be used with either multi-mode or single-mode fiber optic cabling. The connector is made from plastic and uses metal guide pins to ensure that it's properly aligned in the jack. ST has a keyed bayonet connector and is called a push-in-and-twist connector.

You've connected a cable certifier to an RJ45 wall jack, and the output shown below is displayed on the device. What does this output indicate? (Select two.) There are multiple shorts on this cable. This is a crossover cable. This is a straight-through cable. The cable is functioning correctly. There are multiple open pins on this cable.

This is a crossover cable. The cable is functioning correctly. EXPLANATION In this display, the cable being tested is a correctly wired crossover cable. Output with (x) characters between pins indicates that they're shorted. Straight-through connections are displayed using (-) characters in the cable certifier's output. Open connections are displayed with no characters or lines between pin numbers.

Which device sends signals from a computer onto a network? Gateway Cable Transceiver Router

Transceiver EXPLANATION A transceiver (short for transmitter/receiver) sends signals to and receives signals from a network. It translates a computer's parallel data stream to the network's serial data stream, and vice versa. Most transceivers are now built into network interface cards (NICs). A cable transfers the data signals on a network. A router uses its routing table to determine the best route for packets to be sent. A gateway converts data from one protocol or format to another on the network.

During TCP/IP communication between two network hosts, information is encapsulated on the sending host and decapsulated on the receiving host using the OSI model. Match the information format on the left with the appropriate layer of the OSI model on the right. Transport layer Network layer Data Link layer Physical layer

Transport layer - Segments Network layer - Packets Data Link layer - Frames Physical layer - Bits EXPLANATION Encapsulation is the process of breaking a message into packets, adding controls and other information, and transmitting the message through the transmission media. The following is the five-step data encapsulation/decapsulation process used by the OSI model: Upper layers prepare the data to be sent through the network. The Transport layer breaks the data into pieces called segments, adding sequencing and control information. The Network layer converts the segments into packets, adding logical network and device addresses. The Data Link layer converts packets into frames, adding physical device addressing information. The Physical layer converts the frames into bits for transmission across the transmission media.

You have a network that occupies all three floors of a building. The WAN service provider has installed the line in a wiring closet on the main floor. You have a wiring closet on the two remaining floors directly above the wiring closet on the main floor. What would you use to connect the wiring closets together? Vertical cross connect Smart jack Demarc extension Horizontal cross connect

Vertical cross connect EXPLANATION A vertical cross connect joins the main distribution frame (MDF) on the main floor to intermediate distribution frames (IDFs) on upper floors. Cabling runs vertically (up and down) between the MDF and the IDFs. A horizontal cross connect joins IDFs on the same floor. Cabling runs horizontally (sideways) between the IDFs. A smart jack is a special loopback plug installed at the demarcation point for a WAN service. Technicians at the central office can send diagnostic commands to the smart plug to test connectivity between the central office and the demarc. A demarc extension extends the demarcation point from its original location to another location within the building. The demarc extension typically consists of a single wire bundle that attaches to the existing demarc and supplies a termination point to a different location. You might need a demarc extension if your network occupies an upper floor of a building. The LEC typically installs the demarc on the MDF on the bottom floor, and you'll need to install an extension to place the demarc on the IDF on your floor.

How do switches and bridges learn where devices are located on a network? When a frame enters a port, the source IP address is copied from the frame header. When a frame enters a port, the destination IP address is copied from the frame header. When a frame enters a port, the destination MAC address is copied from frame header. When a frame enters a port, the source MAC address is copied from the frame header.

When a frame enters a port, the source MAC address is copied from the frame header. EXPLANATION Bridges and switches learn addresses by copying the MAC address of the source device and placing it into the MAC address table. The port number that the frame entered is also recorded in the table and associated with the source MAC address. The switch or the bridge cannot record the destination MAC address because it does not know the port that is used to reach the destination device.

Why might you use an RJ11 connector? You want to connect a 10GBaseT network to a switch card using a Cat 6 cable. You want to connect your computer to the internet with a DSL modem. You want to upgrade your 10BaseT network to 100BaseTX. You want to connect your computer to a network using a Cat 7 cable.

You want to connect your computer to the internet with a DSL modem. EXPLANATION RJ11 connectors are typically used for telephones and modems. RJ45 connectors are used for 100BaseTX. RJ45 connectors are used for 10GBaseT using Cat 6 cables. GG45 or TERA connectors are used with Cat 7 cables.