Networking Basics 5-7

What is one function of a Layer 2 switch?

A switch builds a MAC address table of MAC addresses and associated port numbers by examining the source MAC address found in inbound frames. To forward a frame onward, the switch examines the destination MAC address, looks in the MAC address for a port number associated with that destination MAC address, and sends it to the specific port. If the destination MAC address is not in the table, the switch forwards the frame out all ports except the inbound port that originated the frame.

What is the purpose of using twisted pairs of wires in an Ethernet cable?

Ethernet technology generally uses twisted-pair cables to interconnect devices. In a twisted-pair cable, wires are grouped in pairs and twisted together to reduce interference.

Which statement is correct about Ethernet switch frame forwarding decisions?

Frame forwarding decisions are based on MAC address and port mappings in the MAC Address table.

Which three acronyms/initialisms represent standards organizations? (Choose three.)

IANA. IETF. 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 will a Layer 2 switch do when the destination MAC address of a received frame is not in the MAC table?

It forwards the frame out of all ports except for the port at which the frame was received.

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.

Data is transmitted across a network on media. Modern networks primarily use three types of media to interconnect devices:

Metal wires within cables (copper cable) - Data is encoded into electrical impulses. Glass or plastic fibers within cables (fiber-optic cable) - Data is encoded into pulses of light. Wireless transmission - Data is encoded via modulation of specific frequencies of electromagnetic waves.

Which term refers to the set of rules that define how a network operates?

Standards ensure that different devices connecting to the network are able to communicate with each other. In networking there are many standards that define how the network should operate and that all components implement the same protocols.

Which organization publishes and manages the Request for Comments (RFC) documents?

The Internet Engineering Task Force (IETF) organization publishes and manages the Request for Comments (RFC).

Which three fields are found in an 802.3 Ethernet frame? (Choose three.

The fields of an Ethernet frame are the preamble, destination and source address, length, data, and FCS.

Which statement is correct about network protocols?

They define how messages are exchanged between the source and the destination. Network protocols are implemented in hardware, or software, or both. They interact with each other within different layers of a protocol stack. Protocols have nothing to do with the installation of the network equipment. Network protocols are required to exchange information between source and destination devices in both local and remote networks

Which information does a switch use to keep the MAC address table information current?

To maintain the MAC address table, the switch uses the source MAC address of the incoming packets and the port that the packets enter. The destination address is used to select the outgoing port.

A network administrator in a small office is upgrading the local network within the building. New network cables are needed to connect office computers and networking devices. Which network media should the administrator use?

Twisted-pair Ethernet cables are most often used to physically connect local devices in a small office to the local network within a building.

Network cabling include different types of cables:

UTP cable consists of four pairs of color-coded wires that have been twisted together and then encased in a flexible plastic sheath. STP cable uses four pairs of wires, each wrapped in a foil shield, which are then wrapped in an overall metallic braid or foil. Coaxial cable uses a copper conductor and a layer of flexible plastic insulation surrounds the copper conductor. Fiber cable is a flexible, extremely thin, transparent strand of glass surrounded by plastic insulation.

Which type of network media carries data encoded into electrical impulses?

copper cable

What process is used to place one message inside another message for transfer from the source to the destination?

encapsulation

A network technician is extending the network from the main office building over several hundred meters to a new security station. The security station needs a high speed connection to support video surveillance of the main building. What type of cable is best suited to connect the security station to the rest of the main office network?

fiber optic

Which type of network media carries data encoded into impulses of light?

fiber-optic cable

What are two common media used in networks? (Choose two.)

fiber. copper

What makes fiber preferable to copper cabling for interconnecting buildings? (Choose three.)

greater bandwidth potential. limited susceptibility to EMI/RFI. greater distances per cable run.

Which two OSI model layers have the same functionality as a single layer of the TCP/IP model? (Choose two.)

physical. data link

What networking term describes a particular set of rules at one layer that govern communication at that layer?

protocol. A protocol dictates how a message is formatted and sets the rules for specific parts of the communication process.

What is the purpose of protocols in data communications?

providing the rules required for a specific type of communication to occur

Which three layers of the OSI model make up the application layer of the TCP/IP model? (Choose three.)

session presentation application

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

Which three factors should be considered when choosing the appropriate network media? (Choose three.)

the distance between hosts that the media will connect. the amount of data and the data transfer rate desired. the environment in which the media is installed

What addressing information is recorded by a switch to build its MAC address table?

the source Layer 2 address of incoming frames

What is the purpose of the FCS field in a frame?

to determine if errors occurred in the transmission and reception

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

Which type of network cable is commonly used to connect office computers to the local network?

twisted-pair cable

Which two types of network media carries data encoded into electrical impulses? (Choose two.)

twisted-pair cable. coaxial cable