Network & Security
10Base2
10Mbps over coaxial cable up to 185 m
Frame check sequence
A 4-byte CRC value used for error detection. The CRC is performed on the bits from the destination MAC address through the Pad fields. If an error is detected, the frame is discarded.
Start frame delimiter
A binary 8-bit sequence of 1 0 1 0 1 0 1 1 that indicates the start of the frame.
ipconfig /all
A command that enables the MAC address information to be displayed from the command prompt
switch
A device that forwards a frame it receives directly out of the port associated with its destination address
range extender
A device that relays the wireless signals from an access point or wireless router into areas with a weak signal or no signal at all
wireless router
A device used to interconnect wireless networking devices and to give access to wired devices and establish the broadband Internet connection to the ISP
Pad
A field used to bring the total number of bytes up to the minimum of 46 if the data field is less than 46 bytes.
frame
A format that provides grouping of information for transmission
Token Ring hub
A hub that manages the passing of the token in a Token Ring network
hotspots
A limited geographic area that provides wireless access for the public
service set identifier (SSID)
A name that is used to identify your wireless network and is used by your access point or wireless router to establish an association
IP internetwork
A network that uses IP addressing for identifying devices connected to the network
wired network
A network that uses radio signals to establish the network connection
wireless network
A network that uses radio signals to establish the network connection
Token Ring topology
A network topology configured in a logical ring that complements the token passing protocol
overloading
A process in which NAT translates a home network's private IP addresses to a single public IP address
virtual private network (VPN)
A secure network connection that helps protect your LAN's data from being observed by outsiders
OSI model
A seven-layer model that describes network functions
bus topology
A system in which the computers share the media (coaxial cable) for data transmission
token passing
A technique in which an electrical token circulates around a network, and control of the token enables the user to gain access to the network
port address translation (PAT)
A technique that involves tracking a port number with the client computer's private address when translating to a public address
network address translation (NAT)
A technique that involves translating a private IP address to a public address for routing over the Internet
Mesh Topology
A topology in which all networking devices are directly connected to each other
stateful packet inspection (SPI)
A type of firewall that inspects incoming data packets to make sure they correspond to an outgoing request
deterministic
A type of network in which access to the network is provided at fixed time intervals
firewall protection
A type of protection used to prevent unauthorized access to your network
IP address
A unique 32-bit address that identifies on which network a computer is located and differentiates the computer from all other devices on the same network
MAC address
A unique 6-byte address assigned by the vendor of a network interface card
Access point
An access point is used to interconnect wireless devices and provide a connection to the wired LAN. The data transfer speeds for access points are dictated by the choice of wireless technology for the clients, but these devices can support up to Wireless-ac.
Preamble
An alternating pattern of 1s and 0s used for synchronization.
port forwarding
An application of NAT in which packets from one IP address/port number are redirected to another
Length/type
An indication of the number of bytes in the data field if this value is less than 1500. (If this number is greater than 1500, it indicates the type of data format—for example, IP and IPX.)
intranets
An internal network that provides file and resource sharing but is not accessed from the Internet
multiport repeater
Another name for a hub
FTP
Application
HTTP
Application
topology
Architecture of a network
CSMA/CD
Carrier sense multiple access with collision detection, the Ethernet LAN media access method
Mesh
Connects all networking devices directly to each other which provides full redundancy in the network paths
Router
Connects two or more networks using a single connection to the ISP (Internet service provider)
Which of the following issues should be considered when planning for a home network?
Data Speed Public Access Cost
hub
Device that broadcasts the data it receives to all devices connected to its ports
Switch
Establishes a direct connection from the sender to the destination without passing the data traffic to other networking devices
VPN
Establishes a secure network connection and helps protect the LAN's data from being observed by outsiders
A protocol defines the network architecture used to interconnect the networking equipment.
False
Class A
Governments, very large networks 0.0.0.0 to 127.255.255.255
private addresses
IP addresses set aside for use in private intranets
Bus
Includes coaxial cable which is looped through each networking device to facilitate data transfer
Star
Includes twisted-pair cables with modular plugs which are used to connect the computers and other networking devices
IEEE
Institute of Electrical and Electronics Engineers, one of the major standards-setting bodies for technological development
access point
Interconnects wireless devices and provides a connection to the wired LAN
IANA
Internet Assigned Numbers Authority, the agency that assigns IP addresses to computer networks
Wireless network
Involves simple installations Slower data transfer speed within the LAN Inexpensive to set up
The NIC operates at which layer of the OSI model?
Layer 1
Physical layer
Layer 1 of the OSI model, which provides the electrical and mechanical connection to the network
Data link layer
Layer 2 of the OSI model, which handles error recovery, flow control (synchronization), and sequencing
Network layer
Layer 3 of the OSI model, which accepts outgoing messages and combines messages or segments into packets, adding a header that includes routing information
TCP functions at which layer of the OSI model?
Layer 4
Transport layer
Layer 4 of the OSI model, which is concerned with message integrity between source and destination
Session layer
Layer 5 of the OSI model, which provides the control functions necessary to establish, manage, and terminate the connections
Presentation layer
Layer 6 of the OSI model, which accepts and structures the messages for the application
HTTP functions at which layer of the OSI model?
Layer 7
Application layer
Layer 7 of the OSI model, which interacts with application programs that incorporate a communication component such as your Internet browser and email
Which of the following network topology is the most expensive to implement?
Mesh
Class B
Midsize companies, universities, and so on 128.0.0.0 to 191.255.255.255
IP
Network
IPX
Network
IP is an example of a protocol that operates in which layer of the OSI model?
None of these.
Ethernet, Physical, Hardware, or Adapter
Other names for the MAC address
Gateway
Provides high-speed data access via a cable or a telephone company's DSL connection
Wired network
Requires the use of specialized tools Faster network data transfer speed
Class D
Reserved for multicast groups 224.0.0.0 to 239.255.255.255
protocol
Set of rules established for users to exchange information
Class C
Small networks 192.0.0.0 to 223.255.255.255
Which of the following network topology requires every host to be connected to the central switch/hub?
Star
How do the IP address and MAC address differ?
The MAC address provides the physical address of the network interface card while the IP address provides the network location.
MAC address
The associated MAC address, which is 6 bytes (12 hex characters) in length.
network interface card
The electronic hardware used to interface a computer to a network
organizationally unique identifier (OUI)
The first 3 bytes of the MAC address that identifies the manufacturer of the network hardware
star topology
The most common networking topology in today's LANs, where all networking devices connect to a central switch or hub
ports
The physical input/output interfaces to networking hardware
host number
The portion of an IP address that defines the location of a networking device connected to the network; also called the host address
network number
The portion of an IP address that defines which network an IP packet is originating from or being delivered to
Destination MAC address and source
The unique media access control address associated with each computer's Ethernet network interface card (NIC) or network adapter.
Data
The variable length of data being transferred from the source to the destination.
DSL modem
This device is used to make a broadband network connection from your home network to the ISP using the telephone line. Broadband access to the Internet is provided via the phone company or a separate ISP. The DSL connection requires the placement of filters on all telephone lines except the one going into the modem to prevent interference.
Cable modem
This device is used to make a broadband network connection from your home network to the ISP, using your cable connection. This setup requires a splitter to separate the cable TV from the home network. Access to the Internet is typically provided by the cable TV service provider.
802.11ac (Wireless-AC)
This is the latest wireless standard. It provides single-station data transfer rates of 1.3Gbps and operates in the 5GHz frequency band.
802.11n (Wireless-N)
This is the next generation of high-speed wireless connectivity promising data transfer rates over 200+ Mbps. It operates at 2.4 Ghz and also 5 GHz. (Modulation - DSSS or OFDM)
802.11b (Wireless-B)
This standard can provide data transfer rates up to 11Mbps, with ranges of 100-150 feet. It operates at 2.4GHz.
802.11a (Wireless-A)
This standard can provide data transfer rates up to 54Mbps and an operating range up to 75 feet. It operates at 5GHz.
802.11g (Wireless-G)
This standard can provide data transfer rates up to 54Mbps up to 150 feet. It operates at 2.4GHz.
Broadband modem/gateway
This type of device is used to provide high-speed data access via your cable connection or via a telephone company's DSL connection. A gateway combines a modem and a router into one network box.
TCP/IP
Transmission Control Protocol/Internet Protocol, the protocol suite used for internetworks such as the Internet
broadcast
Transmission of data by a hub to all devices connected to its ports
TCP
Transport
The MAC address on a Windows computer can be accessed by typing ipconfig /all at the command prompt.
True
Wi-Fi
Wi-Fi close Wi-Fi Alliance—an organization that tests and certifies wireless equipment for compliance with the 802.11x standards
local area network (LAN)
a network of users that share computer resources in a limited area.