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77 terms

ISDS Chapter 7

STUDY
PLAY
computer network
two or more computers connected together via software and hardware so they can communicate
nodes
devices connected to a network
router
enables you to share broadband internet connections
peer-to-peer network
the most common example of a locally administered network
client/server network
the most common type of centrally administered network
peer-to-peer
in this type of network, each node connected to the network can communicate directly with every other node on the network, rather than having a separate device exercise central control over the entire network
client/server network
most networks that have 10 or more nodes
client
in a client/server network, the computer on which users accomplish specific tasks and make specific requests
server
in a client/server network, the computer that provides information or resources to the client computers on the network
server
on a client/server network, provides central control for functions on the network
local area network
networks in which the nodes are located within a small geographic area
wide area network
made up of LANs connected over long distances
transmission media
connect network nodes to each other and to the network
transmission medium
establishes a communications channel between the nodes on a network and can take several forms
data transfer rate
the maximum speed at which data can be transmitted between two nodes on a network
bandwidth
another name for data transfer rate
throughput
the actual speed of data transfer that is achieved; this is usually less than the data transfer rate
network adapters
devices connected to or installed in network nodes that enable the nodes to communicate with each other and to access the network
network interface cards
network adapters that are installed inside computers and peripherals as expansion cards
packets
bunndles in which data is sent over through transmission media
routers and switches
two most common specialized navigation devices
router
transfer packets of data between two or more networks
router
required to send data between the two networks
switches
receive data packets and send them to the node for which they are intended on the same network
networking operating system
client/server networks are controlled by a central server that handles requests for information, Internet access, and the use of peripherals for the rest of the network nodes
ethernet networks
use the Ethernet protocol as the means by which the nodes on the network communicate
ethernet network
requires that you install or attach network adapters to each computer or peripheral you want to connect to the network
unshielded twisted pair cable
most popular transmission medium for wired Ethernet networks
unshielded twisted pair cable
composed of four pairs of wires that are twisted around each other to reduce electrical interference
switch
in an Ethernet network, acts like a traffic signal by enforcing the rules of the data road on the transmission media
switch
in an Ethernet network, acts like a traffic signal by enforcing the rules of the data road on the transmission media
routers
devices that transfer packets of data between two or more networks
wireless network
uses radio waves instead of wires or cables as its transmission media
Wi-Fi
current wireless networks in the United States based on the 802.11 standard
transceiver
a device that translates the electronic data that needs to be sent along the network into radio waves and then broadcasts these radio waves to other network nodes
transceiver
receive signals from other network nodes
wireless access point
a device added to a network to extend the range of the wireless network. It must connect directly to either a switch, a router, or a node on the network
power-line networks
use the existing electrical wiring in your home to connect the nodes in the network
cybercrime
formally defined as any criminal action perpetrated primarily through the use of a computer
cybercriminals
individuals who use computers, networks, and the Internet to perpetrate crime
hacker
as anyone who breaks into a computer system (whether an individual computer or a network) unlawfully
white-hat hackers
hackers who break into systems just for the challenge of it (and who don't wish to steal or wreak havoc on the systems)
white-hat hackers
tout themselves as experts who are performing a needed service for society by helping companies realize the vulnerabilities that exist in their systems
black-hat hackers
hackers who use their knowledge to destroy information or for illegal gain
script kiddies
amateur hackers who use tools created by skilled hackers
packet sniffer
a program that looks at each packet as it travels on the Internet
identity theft
a thief steals your name, address, social security number, and/or bank account and credit card information
trojan horse
a program that appears to be something useful or desirable (like a game or a screen saver) but at the same time does something malicious in the background without your knowledge
backdoor programs
allow hackers to take almost complete control of your computer without your knowledge; hackers can access and delete all files on your computer, send e-mail, run programs, and do just about anything else you can do with your computer
zombies
refers to computers that hackers have control over
denial of service attack
legitimate users are denied access to a computer system because a hacker is repeatedly making requests of that computer system through a computer he or she has taken over as a zombie
distributed denial of service attacks
coordinated attacks launched by hackers from hundreds or thousands of zombies at once
internet connection
the most likely method hackers use to access a computer indirectly
logical ports
virtual communications gateways that allow a computer to organize requests for information from other networks or computers
firewalls
software programs or hardware devices designed to keep computers safe from hackers
virus
a computer program that attaches itself to another computer program (known as the host program) and attempts to spread itself to other computers when files are exchanged
virus
the main purpose is to replicate itself and copy its code into as many other files as possible
boot-sector viruses
viruses that replicate themselves into the hard drive's Master Boot Record
Master Boot Record
a program that executes whenever a computer boots up, ensuring that the virus is loaded immediately
boot-sector virus
viruses that are often transmitted by a floppy disk left in a floppy drive or a flash drive left in a USB port
logic bombs
viruses that are triggered when certain logical conditions are met (such as opening a file)
time bombs
viruses that are triggered by the passage of time or on a certain date
worms
viruses that attempt to travel between systems through networks to spread their infections
scripts
mini programs that are often used to perform legitimate functions on Web sites
macro viruses
viruses that are attached to documents (such as Word files) that use macros
macro
a short series of commands that usually automates repetitive tasks
e-mail viruses
viruses that use the address book in the victim's e-mail system to distribute a virus
encryption viruses
viruses that search for common data files and then compress them using a complex encryption key. The user then has to pay to get the files unlocked
polymorphic viruses
viruses that change their code (or periodically rewrite themselves) to avoid detection
multipartite viruses
viruses that are designed to infect multiple file types in an effort to fool the antivirus software that is looking for them
stealth viruses
viruses that temporarily erase their code from the files where they reside and hide in the active memory of the computer. This helps them avoid detection if only the hard drive is searched for viruses
antivirus software
best defense against viruses
antivirus software
specifically designed to detect viruses and protect your computer and files from harm
virus signatures
are portions of the virus code that are unique to that particular computer virus
antivirus software
scans files for signatures and thereby identifies infected files and the type of virus that is infecting them
quaranteening
the choice of deleting or repairing the infected file and places the virus in a secure area
inoculating
an antivirus program records key attributes about files and re-checks these statistics during a scan