Cisco
In computer communication, what is the purpose of message encoding?
To convert information to the appropriate form for transmission. Before a message is sent across a network it must first be encoded. Encoding is the process of converting the data message into another format suitable for transmission across the physical medium. Each bit of the message is encoded into a pattern of sounds, light waves, or electrical impulses depending on the network media over which the bits are transmitted. The destination host receives and decodes the signals in order to interpret the message.
Why would a technician enter the command copy startup-config running-config?
To copy an existing configuration into RAM Usually, changes are made to a running configuration in RAM and copied to NVRAM. However, in this case, the technician wants to copy a previously saved configuration from NVRAM into RAM in order to make changes to it.?
Which is a function of the Logical Link Control (LLC) sublayer?
To identify which network protocol is being used Defining the media access processes that are performed by the hardware and providing data link layer addressing are functions of the MAC sublayer. The data link layer accepts Layer 3 packets and packages them into data units that are called frames.
What was the reason for the creation and implementation of IPv6?
To relieve IPv4 address depletion. IPv4 addressing space is exhausted by the rapid growth of the Internet and the devices connected to the Internet. IPv6 expands the IP addressing space by increasing the address length from the 32 bits to 128 bits, which should provide sufficient addresses for future Internet growth needs for many years to come.
What is the purpose of the OSI physical layer?
Transmitting bits across the local media The physical layer is responsible for transmitting the actual signals across the physical media as bits. Exchanging frames, controlling media access, and performing error detection are all functions of the data link layer.
Which layer of the OSI model defines services to segment and reassemble data for individual communications between end devices?
Transport The OSI model consists of seven layers: application, presentation, session, transport, network, data link, and physical. The transport layer defines services to segment, transfer, and reassemble the data for individual communications between the end devices.
Which procedure is used to reduce the effect of crosstalk in copper cables?
Twisting opposing circuit wire pairs together. In copper cables, crosstalk is a disturbance caused by the electric or magnetic fields of a signal on one wire interfering with the signal in an adjacent wire. Twisting opposing circuit wire pairs together can effectively cancel the crosstalk. The other options are effective measures to counter the negative effects of EMI and RFI, but not crosstalk.
When a connectionless protocol is in use at a lower layer of the OSI model, how is missing data detected and retransmitted if necessary?
Upper-layer connection-oriented protocols keep track of the data received and can request retransmision from the upper-level protocols on the sending host. When connectionless protocols are in use at a lower layer of the OSI model, upper-level protocols may need to work together on the sending and receiving hosts to account for and retransmit lost data. In some cases, this is not necessary, because for some applications a certain amount of data loss is tolerable.
What is the default SVI on a Cisco switch?
VLAN1 Layer 2 switches use switch virtual interfaces (SVIs) to provide a means for remote access over IP. The default SVI on a Cisco switch is VLAN1
An employee wants to access the network of the organization remotely, in the safest possible way. What network feature would allow an employee to gain secure remote access to a company network?
VPN Virtual private networks (VPN) are used to provide secure access to remote workers.
Which command can be used on a Windows host to display the routing ta
netstat -r On a Windows host, either the route print or netstat -r commands can be used to display the host routing table. The show ip route command is used on a router to display its routing table. The netstat -s command is used to display per-protocol statistics. The tracert command is used to display the path that a packet travels to its destination.
What type of cable is used to connect a workstation serial port to a Cisco router console port?
rollover UTP cable wire pairs can be terminated in different configurations for use in different applications. To use a UTP cable for consoling into a Cisco router from a PC serial port, it must be terminated as a rollover or console cable.
Which network device has the primary function to send data to a specific destination based on the information found in the MAC address table?
switch If a MAC address is found in the MAC address table, then data is sent to the associated switch port. If the MAC address is not found in the MAC address table, the data is sent to all switch ports that have devices attached to the same network.
Which network device makes forwarding decisions based on the destination MAC address that is contained in the frame?
switch Switches are the central connection point for a LAN and they maintain a MAC address table. The MAC address table has a port number associated with a MAC address for each particular device. The switch inspects a frame to look at the destination MAC address. The switch then looks in its MAC address table and if that MAC address is found, the switch forwards the data to the port that is associated with that particular MAC address.
A router with a valid operating system contains a configuration file stored in NVRAM. The configuration file has an enable secret password but no console password. When the router boots up, which mode will display?
user EXEC mode If a Cisco IOS device has a valid IOS and a valid configuration file, it will boot into user EXEC mode. A password will be required to enter privileged EXEC mode
What is the special value assigned to the first 24 bits of a multicast MAC address transporting an IPv4 packet?
01-00-5E Just as with multicast IP addresses, there is a special assigned value for multicast MAC addresses. The first 24 bits are set in hex to: 01-00-5E. The remaining 6 hex digits are derived from the lower 23 bits of the IP multicast.
To what subnet does the IP address 10.1.100.50 belong if a subnet mask of 255.255.0.0 is used?
10.1.0.0 The purpose of a subnet mask is to separate the network portion of the address from the host portion of the IP address. The network portion of the IP address is identified by all binary 1s in the subnet mask. Using a subnet mask of 255.255.0.0 identifies the first two octets of the IP address as the network portion.
Which IPv4 address can a host use to ping the loopback interface?
127.0.0.1 A host can ping the loopback interface by sending a packet to a special IPv4 address within the network 127.0.0.0/8.
What are the two sizes (minimum and expected maximum) of an Ethernet frame? (Choose two.)
1518 bytes 64 bytes The minimum Ethernet frame is 64 bytes. The maximum expected Ethernet frame is 1518 bytes. A network technician must know the minimum and expected maximum frame size in order to recognize runt and jumbo frames.
In which scenario would the use of a WISP be recommended?
A farm in a tutal area without wired broadband access. Wireless Internet Service Providers (WISPs) are typically found in rural areas where DSL or cable access is not available. A dish or antenna on the property of the subscriber connects wirelessly to a WISP transmitter, eliminating the need for physical cabling outside the building.
What is auto-MDIX?
A feature that detects Ethernet cable type Auto-MDIX is a feature that is enabled on the latest Cisco switches and that allows the switch to detect and use whatever type of cable is attached to a specific port.
Which device performs the function of determining the path that messages should take through internetworks?
A router A router is used to determine the path that the messages should take through the network. A firewall is used to filter incoming and outgoing traffic. A DSL modem is used to provide Internet connection for a home or an organization.
What type of address is 01-00-5E-0A-00-02?
An address that reaches a specific group of hosts. The multicast MAC address is a special value that begins with 01-00-5E in hexadecimal. It allows a source device to send a packet to a group of devices.
Which functionality is provided by DHCP?
Automatic assignmetn of an IP address to each host. DHCP provides dynamic and automatic IP address assignment to hosts.
How does BYOD change the way in which businesses implement networks?
BYOD provides flexibility in where and how users can access network resources. A BYOD environment requires an organization to accommodate a variety of devices and access methods. Personal devices, which are not under company control, may be involved, so security is critical. Onsite hardware costs will be reduced, allowing a business to focus on delivering collaboration tools and other software to BYOD users
A large corporation has modified its network to allow users to access network resources from their personal laptops and smart phones. Which networking trend does this describe?
Bring your own device BYOD allows end users to use personal tools to access the corporate network. Allowing this trend can have major impacts on a network, such as security and compatibility with corporate software and devices
What type of communication will send a message to all devices on a local area network?
Broadcast Broadcast communication is a one-to-all communication. A unicast communication is a one-to-one communication. Multicast is a one-to-many communication where the message is delivered to a specific group of hosts. Allcast is not a standard term to describe message delivery.
Which message delivery option is used when all devices need to receive the same message simultaneously?
Broadcast When all devices need to receive the same message simultaneously, the message would be delivered as a broadcast. Unicast delivery occurs when one source host sends a message to one destination host. The sending of the same message from a host to a group of destination hosts is multicast delivery. Duplex communications refers to the ability of the medium to carry messages in both directions
Which data link layer media access control method does Ethernet use with legacy Ethernet hubs?
CSMA/CD CSMA/CD is used by Ethernet networks using legacy Ethernet hubs. CSMA/CA is used by 802.11-based wireless networks.
What is a characteristic of UTP cabling?
Cancellation. Cladding and immunization from electrical hazards are characteristics for fiber-optic cabling. A woven copper braid or metallic foil is used as a shield for the inner coaxial cable conductor. Cancellation is a property of UTP cabling where two wires are located adjacent to one another so each magnetic field cancels out the adjacent magnetic field.
Which layer of the OSI model is responsible for specifying the encapsulation method used for specific types of media?
Data link Encapsulation is a function of the data link layer. Different media types require different data link layer encapsulation.
Which statement describes the half-duplex mode of data transmission?
Data that is transmitted over the network flows in one direction at a time. The data that is transmitted over the network can flow using one of three modes: Simplex - Data can only flow in one direction. Half-duplex - Data flows in one direction at a time. Full-duplex - Data flows in both directions at the same time.
What process is used to receive transmitted data and convert it into a readable message?
Decoding. Decoding is the process of receiving transmitted data and reversing the encoding process to interpret the information. An example is a person that listens to a voicemail and decodes the sounds to understand the received message.
Which logical address is used for delivery of data to a remote network?
Destination IP address The destination IP address is used for end-to-end delivery of data to a remote network. The destination MAC address is used for delivery on a local network. The destination port number identifies the application that should process the data at the destination. Source addresses identify the sender of the data.
When a router receives a packet, what information must be examined in order for the packet to be forwarded to a remote destination?
Destination IP address. 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 information is used by routers to forward a data packet toward its destination?
Destination address The value in the Destination Address field in an IPv4 header will stay the same during its transmission. The other options might change during its transmission.
Which two functions are provided to users by the context-sensitive help feature of the Cisco IOS CLI? (Choose two.)
Displaying a list of all available commands within the current mode. Determining which option, keyword, or argument is available for the entered command. Context-sensitive help provides the user with a list of commands and the arguments associated with those commands within the current mode of a networking device. A syntax checker provides error checks on submitted commands and the TAB key can be used for command completion if a partial command is entered.
What process is used to place one message inside another message for transfer from the source to the destination?
Encapsultaion Encapsulation is the process of placing one message format into another message format. An example is how a packet is placed in its entirety into the data field as it is encapsulated into a frame.
Which term refers to a network that provides secure access to the corporate offices by suppliers, customers and collaborators?
Extranet The term Internet refers to the worldwide collection of connected networks. Intranet refers to a private connection of LANs and WANS that belong to an organization and is designed to be accessible to the members of the organization, employees, or others with authorization. Extranets provide secure and safe access to suppliers, customers, and collaborators. Extendednet is not a type of network.
A college is building a new dormitory on its campus. Workers are digging in the ground to install a new water pipe for the dormitory. A worker accidentally damages a fiber optic cable that connects two of the existing dormitories to the campus data center. Although the cable has been cut, students in the dormitories only experience a very short interruption of network services. What characteristic of the network is shown here?
Faulst tolerance Fault tolerance is the characteristic of a network which allows it to quickly respond to failures of network devices, media, or services. Quality of service refers to the measures taken to ensure that network traffic requiring higher throughput receives the required network resources. Scalability refers to the ability of the network to grow to accommodate new requirements. Security refers to protecting networks and data from theft, alteration, or destruction. Integrity refers to the completeness of something and is generally not used as a characteristic of networks in the same way as the other terms.
A web client is sending a request for a webpage to a web server. From the perspective of the client, what is the correct order of the protocol stack that is used to prepare the request for transmission?
HTTP, TCP, IP, Ethernet 1. HTTP governs the way that a web server and client interact. 2. TCP manages individual conversations between web servers and clients. 3. IP is responsible for delivery across the best path to the destination. 4. Ethernet takes the packet from IP and formats it for transmission.
Which field in an IPv6 packet is used by the router to determine if a packet has expired and should be dropped?
Hop limit ICMPv6, like IPv4, sends a Time Exceeded message if the router cannot forward an IPv6 packet because the packet has expired. However, the IPv6 packet does not have a TTL field. Instead, it uses the Hop Limit field to determine if the packet has expired.
Which two protocols function at the internet layer? (Choose two.)
ICMP IP ICMP and IP both function at the internet layer, whereas PPP is a network access layer protocol, and POP and BOOTP are application layer protocols.
Which standards organization oversees development of wireless LAN standards?
IEEE IANA oversees the management of IP address allocation and domain names. ISO is the largest developer of international networking standards and is famous for the Open Systems Interconnection (OSI) model. TIA focuses on communication standards. The IEEE 802 standards are many, but the ones that affect an entry-level network professional are Ethernet (802.3), wireless LANs (802.11), and wireless PANs (802.15).
Which two engineering organizations define open standards and protocols that apply to the data link layer? (Choose two.)
IEEE ITU The IANA is responsible for overseeing and managing IP address allocation, domain name management, and protocol identifiers. The EIA is an international standards and trade alliance for electronics organizations, and is best known for its standards related to electrical wiring, connectors, and the 19-inch racks used to mount networking equipment. IEEE defines open standards and protocols that apply to the network access layer.
Which three acronyms/initialisms represent standards organizations? (Choose three.)
IETF IEEE IANA TCP/IP is a protocol stack that contains a lot of other protocols such as HTTP, FTP, and DNS. The TCP/IP protocol stack is required to be used when communicating on the Internet. A MAC address is an address that is burned into an Ethernet network card. OSI is the 7 layer model that is used to explain how networking works.
What type of information is contained in an ARP table?
IPv4 address to MAC address mappings ARP tables are used to store mappings of IPv4 addresses to MAC addresses. When a network device needs to forward a packet, the device knows only the IPv4 address. To deliver the packet on an Ethernet network, a MAC address is needed. ARP resolves the MAC address and stores it in an ARP table.
Which statement accurately describes a characteristic of IPv4?
IPv4 has a 32-bit address space. IPv4 has a 32-bit address space, providing 4,294,967,296 unique addresses, but only 3.7 billion are assignable, a limit due to address reservation for multicasting and testing. IPv4 does not provide native support for IPsec. IPv6 has a simplified header with fewer fields than IPv4 has.
Which statement is true about the running configuration file in a Cisco IOS device?
It affects the opration of the divice immediately when modified. As soon as configuration commands are entered into a router, they modify the device immediately. Running configuration files can not be deleted nor are they saved automatically.
Which function or operation is performed by the LLC sublayer?
It communicates with upper protocol layers. The Ethernet LLC sublayer has the responsibility to handle communication between the upper layers and the lower layers of the protocol stack. The LLC is implemented in software and communicates with the upper layers of the application to transition the packet to the lower layers for delivery.
Which statement correctly describes frame encoding?
It converts bits into a predefined code in order to provide a predictable pattern to help ditinguish data bits from control bits. Frame encoding converts a stream of data bits into a predefined code that is recognized by both the sender and receiver. These codes are used for a variety of purposes, such as distinguishing data bits from control bits, and identifying the beginning and end of a frame
What is the function of the shell in an OS?
It interfaces between the users and the kernel. Most operating systems contain a shell and a kernel. The kernel interacts with the hardware and the shell interfaces between the kernel and the users.
What is one advantage of using fiber optic cabling rather than copper cabling?
It is able to carry signals much farther than copper cabling. 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.
What is an ISP?
It is an organization that enables individuals and businesses to connect to the Internet. An ISP, or Internet Service Provider, is an organization that provides access to the Internet for businesses and individuals.
What is done to an IP packet before it is transmitted over the physical medium?
It is encapsulated in Layer 2 frame. When messages are sent on a network, the encapsulation process works from the top of the OSI or TCP/IP model to the bottom. At each layer of the model, the upper layer information is encapsulated into the data field of the next protocol. For example, before an IP packet can be sent, it is encapsulated in a data link frame at Layer 2 so that it can be sent over the physical medium
Which two functions or operations are performed by the MAC sublayer? (Choose two.
It is responsible for Media Access Control It adds a ehader and trailer to for an OSI Layer 2 PDU The MAC sublayer is the lower of the two data link sublayers and is closest to the physical layer. The two primary functions of the MAC sublayer are to encapsulate the data from the upper layer protocols and to control access to the media.
Which two characteristics describe Ethernet technology? (Choose two.)
It is supported by IEEE 802.3 standards. It uses anique MAC addresses to ensure that data is sent to the appropriate destination. The 802.3 Ethernet standard specifies that a network implement the CSMA/CD access control method. Each node on the network has a unique MAC address for communication purposes
What are two benefits of using a layered network model? (Choose two.)
It prevents technology in one layer from affecting other layers. It assists in protocol design. Some vendors have developed their own reference models and protocols. Today, if a device is to communicate on the Internet, the device must use the TCP/IP model. The benefits of using a layered model are as follows: -assists in protocol design -fosters competition between vendors -prevents a technology that functions at one layer from affecting any other layer -provides a common language for describing network functionality -helps in visualizing the interaction between each layer and protocols between each layer
What is the Internet?
It provides connections through interconnected global networks. The Internet provides global connections that enable networked devices (workstations and mobile devices) with different network technologies, such as Ethernet, DSL/cable, and serial connections, to communicate. A private network for an organization with LAN and WAN connections is an intranet.
What are two services performed by the data link layer of the OSI model? (Choose two.)
It provides media access control and performs error detection. It accepts Layer 3 packets and encapsulates the into frames. The data link layer is responsible for the exchange of frames between nodes over a physical network media. Specifically the data link layer performs two basic services: It accepts Layer 3 packets and encapsulates them into frames. It provides media access control and performs error detection. Path determination is a service provided at Layer 3. A Layer 2 switch builds a MAC address table as part of its operation, but path determination is not the service that is provided by the data link layer.
What will a host on an Ethernet network do if it receives a frame with a unicast destination MAC address that does not match its own MAC address?
It will discard the frame In an Ethernet network, each NIC in the network checks every arriving frame to see if the destination MAC address in the frame matches its own MAC address. If there is no match, the device discards the frame. If there is a match, the NIC passes the frame up to the next OSI layer.
What are the two sublayers of the OSI model data link layer? (Choose two.)
LLC MAC The data link layer of the OSI model is divided into two sublayers: the Media Access Control (MAC) sublayer and the Logical Link Control (LLC) sublayer.
What is true concerning physical and logical topologies?
Logical topologies refer to how a network transfers data between devices. Physical topologies show the physical interconnection of devices. Logical topologies show the way the network will transfer data between connected nodes.
What identifier is used at the data link layer to uniquely identify an Ethernet device?
MAC address Ethernet frames are identified at the data link layer by their MAC addresses, which are unique to each NIC. IP addresses are used at the network layer, and TCP and UDP port numbers are used at the transport layer. Sequence numbers are fields in TCP headers.
What attribute of a NIC would place it at the data link layer of the OSI model?
MAC address The data link layer describes media access and physical addressing. The encoding of a MAC address on a NIC places it at that layer. Ports and cables are placed at the physical layer of the OSI model. IP addresses are placed at the network layer. The TCP/IP protocol stack describes a different model.
A technician has been asked to develop a physical topology for a network that provides a high level of redundancy. Which physical topology requires that every node is attached to every other node on the network?
Mesh The mesh topology provides high availability because every node is connected to all other nodes. Mesh topologies can be found in WANs. A partial mesh topology can also be used where some, but not all, end points connect to one another.
Which type of communication will send a message to a group of host destinations simultaneously?
Multicast Multicast is a one-to-many communication where the message is delivered to a specific group of hosts. Broadcast communication is a one-to-all communication. A unicast communication is a one-to-one communication. Anycast is an IPv6 term and is the sending of data in a one-to-nearest communication.
Which memory location on a Cisco router or switch stores the startup configuration file?
NRAM Which memory location on a Cisco router or switch stores the startup configuration file?
An administrator has just changed the IP address of an interface on an IOS device. What else must be done in order to apply those changes to the device?
Nothing must be done. Changes to teh configuration on an IOS device take effect as soon as teh command is typed correctly and the ENter key has been pressed. Changes to router and switch configurations take effect as soon as the command is entered. For this reason, it is very important that changes to live production devices are always carefully planned before being implemented. If commands are entered that render the device unstable or inaccessible, the device may have to be reloaded, resulting in network downtime
Which two statements are true regarding the user EXEC mode? (Choose two.)
Only some aspects of the router configuration can be viewed. The device prompt for this mode ends with the ">" symbol. User EXEC mode limits access to some show and debug commands. It is the first level of user interface encountered when configuring a router and is intended for investigation of certain functions of the device. The User EXEC prompt is identified with the ">" symbol
A network administrator is troubleshooting connectivity issues on a server. Using a tester, the administrator notices that the signals generated by the server NIC are distorted and not usable. In which layer of the OSI model is the error categorized?
Physical layer The NIC has responsibilities in both Layer 1 and Layer 2. The NIC encodes the frame as a series of signals that are transmitted onto the local media. This is the responsibility of the physical layer of the OSI model. The signal could be in the form of electrical, optical, or radio waves
Which type of access is secured on a Cisco router or switch with the enable secret command?
Privileged EXEC The enable secret command secures access to the privileged EXEC mode of a Cisco router or switch
What is the general term that is used to describe a piece of data at any layer of a networking model?
Protocol data unit The term protocol data unit (PDU) is used to describe a piece of data at any layer of a networking model. A packet is the PDU at the network layer. A frame is the data link layer PDU. A segment is the PDU at the transport layer.
What is the purpose of protocols in data communications?
Providing the rules equired for a specific type of communictaion to occur. Protocols provide rules that define how a message is transmitted across a network. Implementation requirements such as electronic and bandwidth details for data communication are specified by standards. Operating systems are not specified by protocols, but will implement protocols. Protocols determine how and when to send a message but they do not control the contents of a message.
Which memory location on a Cisco router or switch will lose all content when the device is restarted?
RAM RAM is volatile memory and will lose all contents if the router or switch is restarted or shutdown.
Which router component holds the routing table, ARP cache, and running configuration file?
RAM The routing table, ARP cache, and running configuration file are stored in volatile RAM.
Which two Internet connection options do not require that physical cables be run to the building?
Satellite Cellular Cellular connectivity requires the use of the cell phone network. Satellite connectivity is often used where physical cabling is not available outside the home or business.
What characteristic of a network enables it to quickly grow to support new users and applications without impacting the performance of the service being delivered to existing users?
Scalability Networks must be able to quickly grow to support new users and services, without impacting existing users and services. This ability to grow is known as scalability.
What information is added during encapsulation at OSI Layer 3?
Source and destination IP address IP is a Layer 3 protocol. Layer 3 devices can open the Layer 3 header to inspect the Layer 3 header which contains IP-related information including the source and destination IP addresses
During a routine inspection, a technician discovered that software that was installed on a computer was secretly collecting data about websites that were visited by users of the computer. Which type of threat is affecting this computer?
Spyware Spyware is software that is installed on a network device and that collects information
What type of physical topology can be created by connecting all Ethernet cables to a central device?
Star Devices connected to the Ethernet star topology connect to either a hub or a switch.
Which type of UTP cable is used to connect a PC to a switch port?
Straight-through. A rollover cable is a Cisco proprietary cable used to connect to a router or switch console port. A straight-through (also called patch) cable is usually used to interconnect a host to a switch and a switch to a router. A crossover cable is used to interconnect similar devices together, for example, between two switches, two routers, and two hosts.
What are two characteristics of a scalable network?
Suitable for modulaer devices that allow for expansion Grows in size without impacting existing users Scalable networks are networks that can grow without requiring costly replacement of existing network devices. One way to make a network scalable is to buy networking devices that are modular.
Which characteristic describes an IPv6 enhancement over IPv4?
The IPv6 header is simpler than the IPv4 header is, which improves packet hadnling. IPv6 addresses are based on 128-bit hierarchical addressing, and the IPv6 header has been simplified with fewer fields, improving packet handling. IPv6 natively supports authentication and privacy capabilities as opposed to IPv4 that needs additional features to support those. The IPv6 address space is many times bigger than IPv4 address space.
What type of network must a home user access in order to do online shopping?
The Internet Home users will go online shopping over the Internet because online vendors are accessed through the Internet. An intranet is basically a local area network for internal use only. An extranet is a network for external partners to access certain resources inside an organization. A home user does not necessarily need a LAN to access the Internet. For example, a PC connects directly to the ISP through a modem.
How does the network layer use the MTU value?
The MTU is passed to the network layer by the data link layer. The data link layer indicates to the network layer the MTU for the medium that is being used. The network layer uses that information to determine how large the packet can be when it is forwarded. When packets are received on one medium and forwarded on a medium with a smaller MTU, the network layer device can fragment the packet to accommodate the smaller size.
What is the definition of bandwidth?
The amount of data that can flow from one place to another in a given amount of time. Bandwidth is the measure of the capacity of a network medium to carry data. It is the amount of data that can move between two points on the network over a specific period of time, typically one second
Which characteristic describes crosstalk?
The distortion of the transmitted messages from signals carried in adjacent wires. EMI and RFI can distort network signals because of interference from fluorescent lights or electric motors. Attenuation results in deterioration of the network signal as it travels along copper cabling. Wireless devices can experience loss of signals because of excessive distances from a access point, but this is not crosstalk. Crosstalk is the disturbance caused by the electric or magnetic fields of the signal carried on an adjacent wire within the same cable
A network administrator is designing a new network infrastructure that includes both wired and wireless connectivity. Under which situation would a wireless connection be recommended?
The end-user divce needs mobility when connecting to the network. When the end-user devices need mobility to connect to the network, wireless is recommended. If an end-user device only has an Ethernet NIC, the user will only be able to use Ethernet cabling. If RFI is an issue, wireless is not recommended. An end-user device that requires a dedicated connection for performance would perform better with a dedicated Ethernet cable.
Which statement is true about MAC addresses?
The first three bytes are used by the vendor assigned OUI. A MAC address is composed of 6 bytes. The first 3 bytes are used for vendor identification and the last 3 bytes must be assigned a unique value within the same OUI. MAC addresses are implemented in hardware. A NIC needs a MAC address to communicate over the LAN. The IEEE regulates the MAC addresses.
What happens to runt frames received by a Cisco Ethernet switch?
The frame is dropped. In an attempt to conserve bandwidth and not forward useless frames, Ethernet devices drop frames that are considered to be runt (less than 64 bytes) or jumbo (greater than 1500 bytes) frames.
When a hostname is configured through the Cisco CLI, which three naming conventions are part of the guidelines? (Choose three.)
The hostname should begin with a letter. The hostname should contain no spaces. The hostname should be fewer than 64 characters in legth. A hostname can be configured with upper or lower case characters and should end with a letter or digit, not a special character. A hostname should start with a letter and no space is allowed for a hostname
What is indicated by the term throughput?
The measure of the bits transferred across the media over a given period of time. Throughput is the measure of the transfer of bits across the media over a given period of time. Throughput is affected by a number of factors such as, EMI and latency, so it rarely matches the specified bandwidth for a network medium. The throughput measurement includes user data bits and other data bits, such as overhead, acknowledging, and encapsulation. The measure of the usable data transferred across the media is called goodput.
A wireless LAN is being deployed inside the new one room office that is occupied by the park ranger. The office is located at the highest part of the national park. After network testing is complete, the technicians report that the wireless LAN signal is occasionally affected by some type of interference. What is a possible cause of the signal distortion?
The microwave oven. Wireless LAN connectivity is not affected by trees or the elevation of the equipment. Because this is a one room office in an isolated area, there will not be a large number of wireless devices or source of interference operating in the immediate vicinity. The use of a microwave oven could result in signal interference.
A computer has to send a packet to a destination host in the same LAN. How will the packet be sent?
The packet will be sent directly to the destination host. If the destination host is in the same LAN as the source host, there is no need for a default gateway. A default gateway is needed if a packet needs to be sent outside the LAN.
What addressing information is recorded by a switch to build its MAC address table?
The source layer 2 address of incoming frames A switch builds a MAC address table by inspecting incoming Layer 2 frames and recording the source MAC address found in the frame header. The discovered and recorded MAC address is then associated with the port used to receive the frame.
Although CSMA/CD is still a feature of Ethernet, why is it no longer necessary?
The use of full-duplex capable Layer 2 switches. The use of Layer 2 switches operating in full-duplex mode eliminates collisions, thereby eliminating the need for CSMA/CD.
Why are two strands of fiber used for a single fiber optic connection?
They allow for full-duplex connectivity. Light can only travel in one direction down a single strand of fiber. In order to allow for full-duplex communication two strands of fiber must be connected between each device.
What are two functions of end devices on a network?
They are the interface between humans and the communication network. They orginiate the data that flows thourgh the network. End devices originate the data that flows through the network. Intermediary devices direct data over alternate paths in the event of link failures and filter the flow of data to enhance security. Network media provide the channel through which network messages travel
What statement describes a characteristic of MAC addresses?
They must be globally unique Any vendor selling Ethernet devices must register with the IEEE to ensure the vendor is assigned a unique 24-bit code, which becomes the first 24 bits of the MAC address. The last 24 bits of the MAC address are generated per hardware device. This helps to ensure globally unique addresses for each Ethernet device.
