Download Networking and Security Handout

Networking and Security: Connecting Computers and
Keeping them Safe From Hackers and Viruses
1. What is a network, and what are the advantages of setting up one?
A computer network is simply two or more computers that are connected using software and hardware so that they
can communicate. Networks allow users to (1) share peripherals, (2) transfer files easily, and (3) share an Internet
connection.
2. What is the difference between a client/server network and a peer-topeer network?
In peer-to-peer networks, each node connected to the network can communicate directly with every other node
instead of having a separate device exercise central control over the network. P2P networks are the most common
type of network installed in homes. Most networks that have 10 or more nodes are client/server networks. A
client/server network contains two types of computers: a client computer on which users accomplish specific tasks,
and a server computer that provides resources to the clients and central control for the network.
3. What are the main hardware components of every network?
To function, any network contains four components: (1) transmission media (cables or radio waves) to connect and
establish communication between nodes; (2) network adapters that allow the nodes on the network to
communicate; (3) network navigation devices (such as routers and hubs) that move data around the network; and
(4) software that allows the network to run.
4. What are the most common home networks?
The two most common home networks are wired Ethernet and wireless Ethernet. Modern power-line networks,
boasting faster data throughput, are now a viable option in certain situations. The major difference in these
networks is the transmission media by which the nodes are connected.
5. What are wired Ethernet networks, and how are they created?
Ethernet networks use the Ethernet protocol as the means by which the nodes on the network communicate. This
protocol makes Ethernet networks efficient but also slightly complex. Because of this complexity, additional devices
(switches or routers) are required in Ethernet networks. To create a wired Ethernet network, you connect or install
network adapters or NICs to each network node. Network adapters connect via cables to a central network
navigation device such as a switch or a router. Data flows through the navigation device to the nodes on the
network.
6. What are wireless Ethernet networks, and how are they created?
A wireless network uses radio waves instead of wires or cable as its transmission media. Current wireless protocols
provide for networks with a maximum of 108 Mbps. To create a wireless network, you install or attach wireless
network adapters to the nodes that will make up the network. If the nodes are unable to communicate because of
distance, then you can add a wireless access point to the network to help relay data between nodes. Wireless
networks are susceptible to interference from other wireless devices such as phones.
7. How are power-line networks created, and are they a viable alternative to Ethernet networks?
Power-line networks use the electrical wiring in your home to connect the nodes in the network. To create a
power-line network, you connect special network adapters to each node on the network. These adapters are then
plugged into an electrical outlet, and data is transmitted through the electrical wires. Modern power-line networks
can often exceed the throughput achieved in wireless Ethernet networks, making them a viable option when
interference with wireless signals is present.
8. How do I configure my computer’s software to set up a network?
Windows Vista and XP both feature software wizards that facilitate the setup of both wired and wireless networks.
Plug in the modem, routers, and all cables and then switch on the modem, router, and computers (in that order).
Run the wizards, which should guide you through the process. Make sure each computer has a distinct name and
ensure that all computers are in the same workgroup.
9. How can hackers attack a network, and what harm can they cause?
A hacker is defined as anyone who breaks into a computer system unlawfully. Hackers can use software to break
into almost any computer connected to the Internet (unless proper precautions are taken). Once hackers gain access
to a computer, they can potentially (1) steal personal or other important information; (2) damage and destroy data;
or (3) use the computer to attack other computers.
10. What is a firewall, and how does it keep my computer safe from hackers?
Firewalls are software programs or hardware devices designed to keep computers safe from hackers. By using a
personal firewall, you can close open logical ports to invaders and potentially make your computer invisible to other
computers on the Internet.
11. Why are wireless networks more vulnerable than wired networks, and what special precautions are required to
ensure my wireless network is secure?
Wireless networks are even more susceptible to hacking than wired networks because the signals of most wireless
networks extend beyond the walls of your home. Neighbors may unintentionally (or intentionally) connect to the
Internet through your wireless connection, and hackers may try to access it. To prevent unwanted intrusions into
your network, you should change the default password on your router (to make it tougher for hackers to gain
access), use a hard-to-guess SSID (network name), turn off SSID broadcasting (to make it harder for outsiders to
detect your network), and enable security protocols such as WPA or WEP.
12. From which types of viruses do I need to protect my computer?
A computer virus is a program that attaches itself to another program and attempts to spread itself to other
computers when files are exchanged. Computer viruses can be grouped into six categories: (1) boot-sector viruses,
(2) logic bombs and time bombs, (3) worms, (4) scripts and macros, (5) encryption viruses, and (6) Trojan horses.
Once run, they perform their malicious duties in the background, often invisible to the user.
13. What can I do to protect my computer from viruses?
The best defense against viruses is to install antivirus software. You should update the software on a regular basis
and configure it to examine all e-mail attachments for viruses. You should periodically run a complete virus scan
on your computer to ensure that no viruses have made it onto your hard drive.