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Cable is the medium through which information usually moves from one network device to another. There are several types of cable which are commonly used with LANs. In some cases, a network will utilize only one type of cable, other networks will use a variety of cable types. The type of cable chosen for a network is related to the network's topology, protocol, and size. Understanding the characteristics of different types of cable and how they relate to other aspects of a network is necessary for the development of a successful network.

The following sections discuss the types of cables used in networks and other related topics.

* Unshielded Twisted Pair (UTP) Cable
* Shielded Twisted Pair (STP) Cable
* Coaxial Cable
* Fiber Optic Cable
* Wireless LANs
* Cable Installation Guides



Unshielded Twisted Pair (UTP) Cable

Twisted pair cabling comes in two varieties: shielded and unshielded. Unshielded twisted pair (UTP) is the most popular and is generally the best option for school networks.



The quality of UTP may vary from telephone-grade wire to extremely high-speed cable. The cable has four pairs of wires inside the jacket. Each pair is twisted with a different number of twists per inch to help eliminate interference from adjacent pairs and other electrical devices. The tighter the twisting, the higher the supported transmission rate and the greater the cost per foot. The EIA/TIA (Electronic Industry Association/Telecommunication Industry Association) has established standards of UTP and rated five categories of wire.
Categories of Unshielded Twisted Pair
Type Use
Category 1 Voice Only (Telephone Wire)
Category 2 Data to 4 Mbps (LocalTalk)
Category 3 Data to 10 Mbps (Ethernet)
Category 4 Data to 20 Mbps (16 Mbps Token Ring)
Category 5 Data to 100 Mbps (Fast Ethernet)

Buy the best cable you can afford; most schools purchase Category 3 or Category 5. If you are designing a 10 Mbps Ethernet network and are considering the cost savings of buying Category 3 wire instead of Category 5, remember that the Category 5 cable will provide more "room to grow" as transmission technologies increase. Both Category 3 and Category 5 UTP have a maximum segment length of 100 meters. In Florida, Category 5 cable is required for retrofit grants. 10BaseT refers to the specifications for unshielded twisted pair cable (Category 3, 4, or 5) carrying Ethernet signals. Category 6 is relatively new and is used for gigabit connections.
Unshielded Twisted Pair Connector

The standard connector for unshielded twisted pair cabling is an RJ-45 connector. This is a plastic connector that looks like a large telephone-style connector. A slot allows the RJ-45 to be inserted only one way. RJ stands for Registered Jack, implying that the connector follows a standard borrowed from the telephone industry. This standard designates which wire goes with each pin inside the connector.



Shielded Twisted Pair (STP) Cable

A disadvantage of UTP is that it may be susceptible to radio and electrical frequency interference. Shielded twisted pair (STP) is suitable for environments with electrical interference; however, the extra shielding can make the cables quite bulky. Shielded twisted pair is often used on networks using Token Ring topology.
Coaxial Cable

Coaxial cabling has a single copper conductor at its center. A plastic layer provides insulation between the center conductor and a braided metal shield. The metal shield helps to block any outside interference from fluorescent lights, motors, and other computers.



Although coaxial cabling is difficult to install, it is highly resistant to signal interference. In addition, it can support greater cable lengths between network devices than twisted pair cable. The two types of coaxial cabling are thick coaxial and thin coaxial.

Thin coaxial cable is also referred to as thinnet. 10Base2 refers to the specifications for thin coaxial cable carrying Ethernet signals. The 2 refers to the approximate maximum segment length being 200 meters. In actual fact the maximum segment length is 185 meters. Thin coaxial cable is popular in school networks, especially linear bus networks.

Thick coaxial cable is also referred to as thicknet. 10Base5 refers to the specifications for thick coaxial cable carrying Ethernet signals. The 5 refers to the maximum segment length being 500 meters. Thick coaxial cable has an extra protective plastic cover that helps keep moisture away from the center conductor. This makes thick coaxial a great choice when running longer lengths in a linear bus network. One disadvantage of thick coaxial is that it does not bend easily and is difficult to install.
Coaxial Cable Connectors

The most common type of connector used with coaxial cables is the Bayone-Neill-Concelman (BNC) connector. Different types of adapters are available for BNC connectors, including a T-connector, barrel connector, and terminator. Connectors on the cable are the weakest points in any network. To help avoid problems with your network, always use the BNC connectors that crimp, rather than screw, onto the cable.



Fiber Optic Cable

Fiber optic cabling consists of a center glass core surrounded by several layers of protective materials. It transmits light rather than electronic signals eliminating the problem of electrical interference. This makes it ideal for certain environments that contain a large amount of electrical interference. It has also made it the standard for connecting networks between buildings, due to its immunity to the effects of moisture and lighting.

Fiber optic cable has the ability to transmit signals over much longer distances than coaxial and twisted pair. It also has the capability to carry information at vastly greater speeds. This capacity broadens communication possibilities to include services such as video conferencing and interactive services. The cost of fiber optic cabling is comparable to copper cabling; however, it is more difficult to install and modify. 10BaseF refers to the specifications for fiber optic cable carrying Ethernet signals.



Facts about fiber optic cables:

* Outer insulating jacket is made of Teflon or PVC.
* Kevlar fiber helps to strengthen the cable and prevent breakage.
* A plastic coating is used to cushion the fiber center.
* Center (core) is made of glass or plastic fibers.

Fiber Optic Connector

The most common connector used with fiber optic cable is an ST connector. It is barrel shaped, similar to a BNC connector. A newer connector, the SC, is becoming more popular. It has a squared face and is easier to connect in a confined space.
Ethernet Cable Summary
Specification Cable Type Maximum length
10BaseT Unshielded Twisted Pair 100 meters
10Base2 Thin Coaxial 185 meters
10Base5 Thick Coaxial 500 meters
10BaseF Fiber Optic 2000 meters
100BaseT Unshielded Twisted Pair 100 meters
100BaseTX Unshielded Twisted Pair 220 meters

Wireless LANs

Not all networks are connected with cabling; some networks are wireless. Wireless LANs use high frequency radio signals, infrared light beams, or lasers to communicate between the workstations and the file server or hubs. Each workstation and file server on a wireless network has some sort of transceiver/antenna to send and receive the data. Information is relayed between transceivers as if they were physically connected. For longer distance, wireless communications can also take place through cellular telephone technology, microwave transmission, or by satellite.

Wireless networks are great for allowing laptop computers or remote computers to connect to the LAN. Wireless networks are also beneficial in older buildings where it may be difficult or impossible to install cables.

The two most common types of infrared communications used in schools are line-of-sight and scattered broadcast. Line-of-sight communication means that there must be an unblocked direct line between the workstation and the transceiver. If a person walks within the line-of-sight while there is a transmission, the information would need to be sent again. This kind of obstruction can slow down the wireless network.

Scattered infrared communication is a broadcast of infrared transmissions sent out in multiple directions that bounces off walls and ceilings until it eventually hits the receiver. Networking communications with laser are virtually the same as line-of-sight infrared networks.

Wireless LANs have several disadvantages. They provide poor security, and are susceptible to interference from lights and electronic devices. They are also slower than LANs using cabling.
Installing Cable - Some Guidelines

When running cable, it is best to follow a few simple rules:

* Always use more cable than you need. Leave plenty of slack.
* Test every part of a network as you install it. Even if it is brand new, it may have problems that will be difficult to isolate later.
* Stay at least 3 feet away from fluorescent light boxes and other sources of electrical interference.
* If it is necessary to run cable across the floor, cover the cable with cable protectors.
* Label both ends of each cable.
* Use cable ties (not tape) to keep cables in the same location together.

How many times have you downloaded an app that could supposedly solve all of your computer problems absolutely free of cost? Now ask yourself how many times that app actually did what it was supposed to, or better yet how many times that app was actually free? More often than not your answer is going to be zero.

Unfortunately for all of us, most software providers use gimmicks to sucker consumers in to purchasing their enterprise security apps: Sure, they'll keep your computer virus free for 30 days, but after that you'll need a subscription. Otherwise they'll just scan your registry for bugs but won't fix them for you. Frankly, we're tired of that.

To keep your computer safe (and save some cash while doing it) we've assembled a list of 103 free security apps for Mac, Windows and Linux. By the end of the article you should have enough resources to secure even the most naïve system, for free!

Spyware
The biggest enemy of the internet user today is spyware. How many computers have you seen rendered useless because of 20 IE toolbars and 15 apps running in the background? To keep your computer running at full performance you need a spyware scanner.

1. Ad-Aware SE Personal [Windows] – Popular, comprehensive spyware removal tool. Maintains a large blacklisted spyware database and identifies malicious program code for the best possible detection.
2. Spyware Terminator [Windows] – Monitors all running processes in real time and determines their integrity. If spyware is found, moves the files to a quarantined section of the hard drive or deletes the files on system start-up.
3. Spybot - Search & Destory [Windows] – Uses deep scanning techniques to cleanse your system of the most obscure forms of spyware. Allows you to blacklist certain types of spyware in order to prevent it from showing up on your system again.
4. Winpooch [Windows] – Intercepts programs in real time via API hooking; determines the integrity of the program and shuts out spyware and Trojan horses from writing in a system directory, connecting to the internet, or doing anything harmful to the computer.
5. SpywareBlaster [Windows] – Prevents the installation of ActiveX based spyware, blocks tracking cookies and restricts the actions of malicious websites.
6. Bazooka Adware and Spyware Scanner [Windows] – Scans your computer for the more popular types of spyware usually found bundled with software packages and removes the malicious content.
7. Windows Defender [Windows] – Microsoft's solution for protecting your computer from spyware and popups.
8. MalWhere [Windows] – Displays detailed information about the processes running on your computer including those that run at start up. Investigates suspicious processes and let's you know when malicious code is being executed. Does not require a spyware definition updating.
9. Trend Micro Anti-Spyware for the Web [Web: Windows] – Online based spyware detection and removal tookit. Perfect solution for non tech savvy users.
10. Zebra scanner [Mac] – Scans files for hidden agendas (e.g. a trojan disguised as an MP3 or image.) Notifies the user of the scanned files integrity. Does not contain a method for disinfecting the computer.

Antivirus
Perhaps the ultimate definition of computer security is the effectiveness of your antivirus. Antivirus software keeps the most problematic forms of malware from corrupting your computer.

1. McAfee AVERT Stinger [Windows] – Tool used to remove specific current popular viruses and worms. Make sure to download the version of Stinger pertaining to the virus found on your machine.
2. PC Tools AntiVirus [Windows] – Comprehensive virus scanning suite offering protection from malicious internet software, email attachments and boot sector viruses. Includes real time virus scanning.
3. Clam AntiVirus [Linux] – Extremely popular antivirus solution for UNIX based machines. Includes real time virus scanning and a virus definition database updated multiple times per day.
4. AVScan [Linux] – A front-end for Clam AntiVirus.
5. ClamXav [Mac] – Uses ClamAV engine to scan files for viruses.
6. AVG Anti-Virus [Windows, Linux] – Effective virus scanning suite. Requires regular virus definition updates.
7. Avast Home Edition [Windows, Linux] – Complete antivirus suite including real time scanning, email protection, internet traffic filtering, a firewall and more.
8. Housecall [Web: Windows, Linux, Mac] – Web based scanner that detects and removes viruses, worms, trojans and spyware. Also points out system vulnerabilities and offers advice on obtaining security patches.
9. Symantec Security Check [Web] – Simple antivirus solution that searches your computer for various forms of malware and deletes them. Offers a secondary scan to measure the vulnerability of your computer.

Rootkit
Rootkits are about the nastiest forms of malware around. To keep your computer (and your privacy) safe, you'll need an app to scan for rootkits.

1. Sophos Anti-Rootkit [Windows] – Removes complex rootkits and various types of malware running in a hidden state from personal and network computers.
2. Rootkit Hunter [Mac] – Searches for popular UNIX and Mac rootkits and removes them.
3. chkrootkit [Linux] – The definitive solution for finding and removing rootkits from Linux machines.

Firewall
A well regarded firewall with a strict rule set is the first line of defense against intruders. Keep hackers from sneaking malware onto your system in the first place with these freebie firewall solutions.

1. ZoneAlarm [Windows] – Popular, comprehensive firewall suite including a highly customizable rule set and a very effective warning system letting you know when your computer is at risk. Be sure to select "I only want basic ZoneAlarm protection" from the download screen (otherwise you'll end up with a trial version.)
2. VisualZone [Windows] – Analyzes ZoneAlarm information including intrusion types and methods of entry. Allows you to gain a clear view of your system's vulnerabilities.
3. PC Tools Firewall Plus [Windows] – User friendly firewall that monitors the applications connecting to the network. Uses a simple rule set to prevent malware from infecting your computer.
4. Firestarter [Linux] – Real time firewall that monitors all of the open ports and active network connections on your computer. Allows you to specify a very strict rule set.
5. Firewall Builder [Linux] – Useful tool for assembling a firewall rule set or policy for popular UNIX based firewalls including iptables, ipfilter, etc.
6. TuxGuardian [Linux] – Verifies the integrity of applications trying to gain access to the network. Useful for preventing viruses, trojans, spyware, etc. from spreading throughout the network.
7. HardWall Firewall [Linux] – Iptables based script that performs detailed packet inspection and filtering to keep your computer free from malicious traffic.
8. BullDog [Linux] – Complex firewall for advanced users.
9. PeerGuardian [Windows, Linux, Mac] – Blocks IPs from accessing your network. Especially useful for protecting your privacy when using peer to peer software.

Network
With an insecure network not only will you be vulnerable to the perils of the internet, everyone connected to your network will too. Meaning instead of having one computer down due to a nasty virus, you could have hundreds. These freebie apps will help you manage the challenge of keeping your network safe.

1. SoftPerfect Network Scanner [Windows] – Displays information about the configuration of your network.
2. SecureRDP [Windows] – Allows you to monitor and reject the incoming RDP connections to your server.
3. Colasoft Packet Player [Windows] – Capture packets and trace their route through your network. Extremely useful for finding bottlenecks and vulnerable points.
4. DomainScan Light [Windows] – Monitor open ports, connected devices, changes made to your network.
5. SmoothWall [Linux] – Firewall, IDS and VPN system for home users and networks.
6. Nagios [Linux] – Comprehensive web based tool equipped with virtually every imaginable feature for knowing exactly what's going on in your network.
7. nLive Core [Linux] – Monitors the traffic that traverses your network via packet inspection and filtering.
8. Network Mapper [Windows, Linux, Mac] – Uses packets passing through the network to find out what hosts are available, what services they're offering, what operating system they're running and what type of packet filtration/firewall they're using.
9. Wireshark [Windows, Linux, Mac] – Powerful tool for capturing network protocol data for analysis. Contains more than 25 methods for reading packets making it useful for a wide array of networks.
10. Nessus [Windows, Linux, Mac] – Industry leading open source network vulnerability scanner. Highly scalable and very thorough.
11. dSniff Control [Mac] – Tool used to test the security of your network. Tries various sniffing and spoofing exploits to gain information about your network.
12. Flame [Mac] – Simple tool used to breakdown the status and events taking place in your network.
13. Server Admin Tools [Mac] – Apple's solution for securing and monitoring a network.

Temporary Files
What websites have you been visiting? What's that, too embarrassed to say? Don't worry, we've got you covered. Simply use one of these apps to delete all of your temporary files and clean up the trail you left behind.

1. HijackThis [Windows] – Scans your computers browser, registry and operating system settings to generate a report of the state of your computer. Allows you to select which software and settings to delete.
2. Zappit System Cleaner [Windows] – Cleans up the footprints you leave when using the computer including: temporary files, recent documents, search and run commands, auto complete internet forms and history and more.
3. CCleaner [Windows] – A system optimization and privacy tool that cleans up the registry, temporary files, cookies, web history and cache and more.
4. WinXPatch [Windows] – A tool used to perform several security upgrades to the default installation and registry.
5. Advanced WindowsCare v2 Personal [Windows] – Cleans up temporary files and the registry to maximize your privacy. Also doubles as a spyware remover.
6. EasyCleaner [Windows] – A comprehensive tool for cleaning up the registry and deleting your footprints on the computer. Includes software to manage programs at start up and free up disk space.
7. CleanCache [Windows] – Deletes the temporary files you leave behind when you surf the internet.
8. xpy [Windows] – Improves the general security of your system by reconfiguring some of the default computer settings.
9. Cookie Eraser [Windows] – A tool to help you identify and erase the unnecessary cookies on your computer.
10. Yet Another System Utility [Mac] – Clears the cache, browser history and other areas where you might have left a footprint while using the computer.

Wireless
Securing your WiFi network is easier than it sounds. By taking a few extra minutes to install a few of the following apps, you'll have your WiFi network on lockdown in no time.

1. Kismet [Linux, Mac] – Very popular wireless network detector, sniffer, and IDS.
2. AirSnare [Windows] – Wireless IDS that alerts you when an unfriendly MAC address is trying to access your network.
3. myWIFIzone [Windows] – Acts as a gateway to block people from accessing your WiFi connection without receiving permission from you first.
4. iOpus Private Internet Gateway [Windows] – Creates a secure tunnel that encrypts your inbound and outbound WiFi communications. Protects your privacy on public networks.
5. LucidLink WiFi Client [Windows] – Simplifies the process of securely connecting to a WiFi network, and warns you when you're connecting to an insecure network.
6. AirTrafficControl [Mac] – Monitors your WiFi connection for quality and security.

Encryption
Encryption is a must for the most sensitive types of data. After all, we all know what happens when a password or credit card number winds up in the wrong persons hands. That's why we recommend you check out a few of the following encryption apps.

1. Pastor [Mac] – Simple tool used to securely store all of your usernames and passwords.
2. Access Manager [Windows] – Stores all of your sensitive passwords and personal information into one secure file.
3. RememberMe [Windows] – Stores your usernames and passwords in an 128-bit AES encrypted file.
4. Kruptos 2 [Windows] – Integrates into windows right click menus to encrypt and archives files easily.
5. Crypt4Free [Windows] – Uses Blowfish and DESX encryption to protect your files and create encrypted messages for instant messaging and email clients.
6. PicSecret [Web, Mac] – Neat feature that allows you to send encrypted messages disguised as ordinary pictures.
7. GNU Privacy Guard [Windows, Linux, Mac] – A command line based encryption tool using multiple encryption algorithms including OpenPGP, AES, SHA-1, and more.
8. TrueCrypt [Windows, Linux] – Creates virtual encrypted drives.

Miscellaneous
Here are few apps that simply didn't fit into the categories above. Although they might be unclassified, they all offer a great deal of functionality when it comes to overall system security.

1. Active Security Monitor [Windows] – Uses a proven system to determine if a user's system is secure or not.
2. PreView 1.0 [Windows] – Rates your computer on how vulnerable it is.
3. PC Security Test [Windows] – Determines the vulnerability of your computer by subjecting it to simulated attacks and malware.
4. PCPal [Windows] – Detects security vulnerabilities in your system and advises you on how to reduce their risks.
5. Simple File Shredder [Windows] – Securely and permanently delete files on your computer.
6. BCWipe [Windows] – Permanently deletes files off of your computer.
7. Permanent Eraser [Mac] – Permanently delete files from your hard drive.
8. S3 Change Explorer [Windows] – Graphically keeps track of the changes made on your system. Useful for determining if a user or file is making unwanted changes to sensitive files.
9. Process Monitor [Windows] – Microsoft's solution for monitoring all of the processes running on your computer. Useful for identifying malware instances.
10. Check Failed Password Attempts [Mac] – Tool used to scan for failed attempts logging into the administrator account.
11. CheckMate [Mac] – Compares checksums of critical files to determine their integrity before you download them. By comparing checksums you'll know if you're getting the right files, or something infected with malware.
12. Checksum Validator [Mac] – A very simple checksums comparison tool.

source :itsecurity

Before we talk about wireless network security, we must first understand how a wireless network operates.

For most home and small business users, a wireless network is basically a set of devices that enable all of the personal computers in your location to use a broadband internet connection simultaneously.

Wireless networks don't use cables for connections, but instead use radio waves, like cordless phones. Also known as Wi-Fi, or Wireless Fidelity, wireless networks allow you to use your networked computers or laptops anywhere in an office or home.

Wireless networking is also available in public "hotspots," like coffee shops, hotel rooms and lobbies, and airports.

You may have heard the term "Internet Cafe". This refers to a place of business (most often, a coffee shop) which offers wireless network access for anyone who wants to bring in a laptop equipped with a wireless network card. The wireless network card picks up the wireless network signal and the two communicate over that signal. Here's a web page which talks about the wireless network security risks of using Internet Cafes, if you are interested.

But, just as with a cell phone, a wireless network (and any computer you have connected to it) can be hacked, especially if it isn't secured.

CAVEAT and Disclaimer: Wireless networks are inherently unsafe and cannot be completely secured, as there are hackers who will always be one step ahead of the commercial security vendors.

So I, Ellen Davis, do not guarantee that your wireless network security will be impenetrable after completing the steps offered on this site.

However, in my opinion, the majority of hackers are going after bigger fish, and don't have much interest in your wireless home network, except maybe to use it for free internet access.

So unless you are storing hundreds of credit card numbers on your computers for some reason, or you have some kind of important information that can be sold on the black market, or you make some hacker mad, applying the steps below will help ensure your wireless network security is at least better than it would be if you did nothing.

Let's take a closer look at setting up a wireless network and the best practices for building in wireless network security.

First, here’s a list of components needed to build a basic home or small office wireless network:

1. Windows based personal computers, and/or personal laptops with Windows XP SP2 installed. (Windows XP SP2 is compatible with WPA2 Personal encryption, which is what I recommend using).

2. WPA2 enabled wired or wireless network adapters, which should be (or may already be) installed in each of your computers.

If you aren't sure whether Windows XP and the network cards installed on your computer are enabled for WPA2, here's an excellent page that walks you through how to upgrade Windows XP, routers and network cards to WPA2.

3. Ethernet cables, also known as CAT5 cables. They come in 3, 6, 10, 25, and 50 foot lengths. Desktop and laptop computers won’t need a cable if a wireless network card in installed.

4. A wireless router that supports WPA and WPA2 encryption. There are many different brands, but I use Linksys wireless routers because they are reliable and easy to set up. They cost around $60 in the big office supply or computer stores.

5. A broadband internet connection.

6. The wireless network security steps below.

Second, you need steps on how to secure a wireless network. I've included the details on how to implement reliable wireless network security below: (I'm assuming that we are in your home or small business office, and that you have a desktop PC wired into your broadband box and that you will be using a new Linksys router):

1. First, you must have either a regular or wireless network card in all of the computers in your house. For most wireless networks, a desktop computer nearest to the broadband jack will be connected via a wired network card and cable. Laptops or any other computer not close to the router will be connected via wireless card (or long CAT 5 cable).

IMPORTANT Note: If you have older network cards, they may not be compatible with the new WPA2 security protocol. Upgrade the drivers or the cards if you have to, because relying on any other security protocol like WEP is just not as good when it comes to wireless security.

You may also need to upgrade Windows XP SP2 to be compatible with WPA2 security. Here's the Microsoft page to do this.

2. If you haven’t done so already, place an order for a broadband (aka high speed) internet service installation with your local internet service provider. (This can be a cable company, the telephone company or a wireless tower provider – shop around for the best deal).

3. Purchase a wireless router and install it. NOTE: Be careful about buying used routers; the previous owner could install malicious software on them that could hurt your computer. New is better if you don’t know how to clean them up.

4. Following the instructions that come with the router, set it up next to the computer that is plugged into the broadband connection box.

5. IMPORTANT!! SECURE your wireless router. Follow each of these steps to make sure your wireless network security is reliable and your network is safe from outside intrusion:

* Change the default wireless network name or SSID to something unique but not personal (no social security numbers or house addresses). The name you choose can be up to 32 characters long and you need to be able to remember it. Linksys sets the default name to Linksys on their routers and every hacker in the world knows that, so don’t leave it unchanged.

* Change the default password. Linksys sets a default password of admin, and every hacker knows that too. Change it to a password that includes both letters and numbers. Avoid using words that can be found in a dictionary. Also, make sure you either remember it or note it somewhere secure. You will need if you want to access your router later to make changes.

* Enable Encryption. Linksys routers offer several kinds of security protocols – WPA, WPA2 and WEP are the major types.

The newest and most secure kind of encryption is WPA2. Both WEP and WPA have already been cracked by hackers. WPA2 is the most secure, so I would implement it over the other choices.

When the router setup asks you to choose a wireless security encryption method, choose security mode "WPA2 Personal". Then choose algorithms "TKIP+AES". Choose a strong password for your encryption key, such as a combination of letters and numbers. It can be from 8 to 63 characters, I would use at least 14 characters. Leave the key renewal interval as it is, and save the setting. Make sure you can remember the key. I hate to tell you to write it down, but if you must, you must.

Later, when you try to connect your wireless clients to your network, the card utility should automatically ask you for the preshared key. Enter it twice and you should get connected. If not, please check that the wireless card in the computer is actually compatible with WPA/WPA2.

Note: If you have an older router that supports WEP only, and you don't want to upgrade it, please remember that WEP is very easy to crack, so your wireless network won't be as secure. You'll be at least safer if you use 128-bit WEP keys, but I would recommend that you check the router manufacturer's website for a firmware upgrade that will add WPA support.

* DON'T turn off SSID Broadcasting. A wireless router can broadcast its SSID name by sending out a continuous radio ping. This is convenient for people trying to connect to it, because they don’t have to remember the name of the network. It seems like it would be good to turn that off, but on Windows XP, it isn't a good idea.

Windows XP, by default, always tries to connect to the first broadcasted wireless network. If you turn off SSID broadcasting, Windows XP won't connect to your network first if it finds a broadcasting network in close enough range. That's not good wireless network security, for sure. So it's best to continue broadcasting while implementing WPA2 encryption instead.

Plus you won't have to choose to connect to "nonbroadcasting networks" on your computers, and then type in the name of the network to connect to it.

* You have now successfully implemented wireless network security on your router that should keep your data relatively safe (see caveat above for more info).

Let's keep going to finish setting up our network, and connecting to the internet.

6. Change the network card settings in each of your PCs to match the router settings. Pay particular attention to the SSID, the type of encryption, and the key you used when you set up the router.

You’ll need to know this info when are ready to connect any wireless PCs or laptops. Wired computers will get the information they need automatically, as long as the network card is set up to use DHCP, which basically means the network card goes out and gets what it needs from the network automatically.

7. If you have a laptop with a wireless card, check to make sure the wifi capabilities are on. NOTE: On some laptops, there is a switch or button on the laptop that turns the wireless network card on or off. If you are having trouble "seeing" the wireless network, you may have to "turn on" your wireless network card.

8. Once your computer network cards have the network information that matches the router, they will connect and you’ll be able to connect to the internet, with confidence that your wireless network security is set up correctly.

9. Note: Look for the wireless signal strength in the system tray located in the bottom right hand corner of your Windows desktop. It will look a bunch of colored bars.

Green means the signal is strong, yellow is weaker, and red means no signal at all.

Walk around your house with your laptop and see how good the signal is in each room.

Being able to work anywhere in your house depends on how big your house is, and where your wireless router is located. As you walk around, you’ll see the signal strength icon in the Windows system tray changed.

Very quickly, you’ll find out the best places to be for full network speed. It's makes working on your computer kind of fun, and now you have the peace of mind that your wireless network security is keeping your computers safe.

All done! You now know the best steps for setting up a wireless network and configuring strong wireless network security. I hope this information helps you keep your computers and your data safe.

One more note: If setting up wireless network security seems a little overwhelming, and you live in Cheyenne, Wyoming, I can help. Send me a note via my contact form, and I’d be happy to come out and set it up for you. My rates are reasonable.

http://www.sensible-computer-help.com

What is Networking Hardware?

Networking hardware includes all computers, peripherals, interface cards and other equipment needed to perform data-processing and communications within the network. CLICK on the terms below to learn more about those pieces of networking hardware.


This section provides information on the following components:

* File Servers
* Workstations
* Network Interface Cards
* Switches
* Repeaters
* Bridges
* Routers

File Servers

A file server stands at the heart of most networks. It is a very fast computer with a large amount of RAM and storage space, along with a fast network interface card. The network operating system software resides on this computer, along with any software applications and data files that need to be shared.

The file server controls the communication of information between the nodes on a network. For example, it may be asked to send a word processor program to one workstation, receive a database file from another workstation, and store an e-mail message during the same time period. This requires a computer that can store a lot of information and share it very quickly. File servers should have at least the following characteristics:

* 800 megahertz or faster microprocessor (Pentium 3 or 4, G4 or G5)
* A fast hard drive with at least 120 gigabytes of storage
* A RAID (Redundant Array of Inexpensive Disks) to preserve data after a disk casualty
* A tape back-up unit (i.e. DAT, JAZ, Zip, or CD-RW drive)
* Numerous expansion slots
* Fast network interface card
* At least of 512 MB of RAM

Workstations

All of the user computers connected to a network are called workstations. A typical workstation is a computer that is configured with a network interface card, networking software, and the appropriate cables. Workstations do not necessarily need floppy disk drives because files can be saved on the file server. Almost any computer can serve as a network workstation.
Network Interface Cards

The network interface card (NIC) provides the physical connection between the network and the computer workstation. Most NICs are internal, with the card fitting into an expansion slot inside the computer. Some computers, such as Mac Classics, use external boxes which are attached to a serial port or a SCSI port. Laptop computers can now be purchased with a network interface card built-in or with network cards that slip into a PCMCIA slot.

Network interface cards are a major factor in determining the speed and performance of a network. It is a good idea to use the fastest network card available for the type of workstation you are using.

The three most common network interface connections are Ethernet cards, LocalTalk connectors, and Token Ring cards. According to a International Data Corporation study, Ethernet is the most popular, followed by Token Ring and LocalTalk (Sant'Angelo, R. (1995). NetWare Unleashed, Indianapolis, IN: Sams Publishing).
Ethernet Cards

Ethernet cards are usually purchased separately from a computer, although many computers (such as the Macintosh) now include an option for a pre-installed Ethernet card. Ethernet cards contain connections for either coaxial or twisted pair cables (or both) (See fig. 1). If it is designed for coaxial cable, the connection will be BNC. If it is designed for twisted pair, it will have a RJ-45 connection. Some Ethernet cards also contain an AUI connector. This can be used to attach coaxial, twisted pair, or fiber optics cable to an Ethernet card. When this method is used there is always an external transceiver attached to the workstation. (See the Cabling section for more information on connectors.)


Fig. 1. Ethernet card.
From top to bottom:
RJ-45, AUI, and BNC connectors
LocalTalk Connectors

LocalTalk is Apple's built-in solution for networking Macintosh computers. It utilizes a special adapter box and a cable that plugs into the printer port of a Macintosh (See fig. 2). A major disadvantage of LocalTalk is that it is slow in comparison to Ethernet. Most Ethernet connections operate at 10 Mbps (Megabits per second). In contrast, LocalTalk operates at only 230 Kbps (or .23 Mbps).


Fig.2. LocalTalk connectors
Ethernet Cards vs. LocalTalk Connections
Ethernet LocalTalk
Fast data transfer (10 to 100 Mbps) Slow data transfer (.23 Mbps)
Expensive - purchased separately Built into Macintosh computers
Requires computer slot No computer slot necessary
Available for most computers Works only on Macintosh computers

Token Ring Cards

Token Ring network cards look similar to Ethernet cards. One visible difference is the type of connector on the back end of the card. Token Ring cards generally have a nine pin DIN type connector to attach the card to the network cable.
Switch

A concentrator is a device that provides a central connection point for cables from workstations, servers, and peripherals. In a star topology, twisted-pair wire is run from each workstation to a central switch/hub. Most switches are active, that is they electrically amplify the signal as it moves from one device to another. Switches no longer broadcast network packets as hubs did in the past, they memorize addressing of computers and send the information to the correct location directly. Switches are:

* Usually configured with 8, 12, or 24 RJ-45 ports
* Often used in a star or star-wired ring topology
* Sold with specialized software for port management
* Also called hubs
* Usually installed in a standardized metal rack that also may store netmodems, bridges, or routers

Repeaters

Since a signal loses strength as it passes along a cable, it is often necessary to boost the signal with a device called a repeater. The repeater electrically amplifies the signal it receives and rebroadcasts it. Repeaters can be separate devices or they can be incorporated into a concentrator. They are used when the total length of your network cable exceeds the standards set for the type of cable being used.

A good example of the use of repeaters would be in a local area network using a star topology with unshielded twisted-pair cabling. The length limit for unshielded twisted-pair cable is 100 meters. The most common configuration is for each workstation to be connected by twisted-pair cable to a multi-port active concentrator. The concentrator amplifies all the signals that pass through it allowing for the total length of cable on the network to exceed the 100 meter limit.
Bridges

A bridge is a device that allows you to segment a large network into two smaller, more efficient networks. If you are adding to an older wiring scheme and want the new network to be up-to-date, a bridge can connect the two.

A bridge monitors the information traffic on both sides of the network so that it can pass packets of information to the correct location. Most bridges can "listen" to the network and automatically figure out the address of each computer on both sides of the bridge. The bridge can inspect each message and, if necessary, broadcast it on the other side of the network.

The bridge manages the traffic to maintain optimum performance on both sides of the network. You might say that the bridge is like a traffic cop at a busy intersection during rush hour. It keeps information flowing on both sides of the network, but it does not allow unnecessary traffic through. Bridges can be used to connect different types of cabling, or physical topologies. They must, however, be used between networks with the same protocol.

Routers

A router translates information from one network to another; it is similar to a superintelligent bridge. Routers select the best path to route a message, based on the destination address and origin. The router can direct traffic to prevent head-on collisions, and is smart enough to know when to direct traffic along back roads and shortcuts.

While bridges know the addresses of all computers on each side of the network, routers know the addresses of computers, bridges, and other routers on the network. Routers can even "listen" to the entire network to determine which sections are busiest -- they can then redirect data around those sections until they clear up.

If you have a school LAN that you want to connect to the Internet, you will need to purchase a router. In this case, the router serves as the translator between the information on your LAN and the Internet. It also determines the best route to send the data over the Internet. Routers can:

* Direct signal traffic efficiently
* Route messages between any two protocols
* Route messages between linear bus, star, and star-wired ring topologies
* Route messages across fiber optic, coaxial, and twisted-pair cabling


Type rest of the post here

One way to categorize the different types of computer network designs is by their scope or scale. For historical reasons, the networking industry refers to nearly every type of design as some kind of area network. Common examples of area network types are:

• LAN - Local Area Network
• WLAN - Wireless Local Area Network
• WAN - Wide Area Network
• MAN - Metropolitan Area Network
• SAN - Storage Area Network, System Area Network, Server Area Network, or sometimes Small Area Network
• CAN - Campus Area Network, Controller Area Network, or sometimes Cluster Area Network
• PAN - Personal Area Network
• DAN - Desk Area Network

LAN and WAN were the original categories of area networks, while the others have gradually emerged over many years of technology evolution.

Note that these network types are a separate concept from network topologies such as bus, ring and star.

LAN - Local Area Network
A LAN connects network devices over a relatively short distance. A networked office building, school, or home usually contains a single LAN, though sometimes one building will contain a few small LANs (perhaps one per room), and occasionally a LAN will span a group of nearby buildings. In TCP/IP networking, a LAN is often but not always implemented as a single IP subnet.

In addition to operating in a limited space, LANs are also typically owned, controlled, and managed by a single person or organization. They also tend to use certain connectivity technologies, primarily Ethernet and Token Ring.

WAN - Wide Area Network
As the term implies, a WAN spans a large physical distance. The Internet is the largest WAN, spanning the Earth.

A WAN is a geographically-dispersed collection of LANs. A network device called a router connects LANs to a WAN. In IP networking, the router maintains both a LAN address and a WAN address.

A WAN differs from a LAN in several important ways. Most WANs (like the Internet) are not owned by any one organization but rather exist under collective or distributed ownership and management. WANs tend to use technology like ATM, Frame Relay and X.25 for connectivity over the longer distances.
LAN, WAN and Home Networking
Residences typically employ one LAN and connect to the Internet WAN via an Internet Service Provider (ISP) using a broadband modem. The ISP provides a WAN IP address to the modem, and all of the computers on the home network use LAN (so-called private) IP addresses. All computers on the home LAN can communicate directly with each other but must go through a central gateway, typically a broadband router, to reach the ISP.

Other Types of Area Networks
While LAN and WAN are by far the most popular network types mentioned, you may also commonly see references to these others:

• Wireless Local Area Network - a LAN based on WiFi wireless network technology
• Metropolitan Area Network - a network spanning a physical area larger than a LAN but smaller than a WAN, such as a city. A MAN is typically owned an operated by a single entity such as a government body or large corporation.
• Campus Area Network - a network spanning multiple LANs but smaller than a MAN, such as on a university or local business campus.
• Storage Area Network - connects servers to data storage devices through a technology like Fibre Channel.
• System Area Network - links high-performance computers with high-speed connections in a cluster configuration. Also known as Cluster Area Network.

In computer networking, topology refers to the layout of connected devices. This article introduces the standard topologies of networking.
Topology in Network Design
Think of a topology as a network's virtual shape or structure. This shape does not necessarily correspond to the actual physical layout of the devices on the network. For example, the computers on a home LAN may be arranged in a circle in a family room, but it would be highly unlikely to find a ring topology there.

Network topologies are categorized into the following basic types:

* bus
* ring
* star
* tree
* mesh

More complex networks can be built as hybrids of two or more of the above basic topologies.

Bus Topology
Bus networks (not to be confused with the system bus of a computer) use a common backbone to connect all devices. A single cable, the backbone functions as a shared communication medium that devices attach or tap into with an interface connector. A device wanting to communicate with another device on the network sends a broadcast message onto the wire that all other devices see, but only the intended recipient actually accepts and processes the message.



Ethernet bus topologies are relatively easy to install and don't require much cabling compared to the alternatives. 10Base-2 ("ThinNet") and 10Base-5 ("ThickNet") both were popular Ethernet cabling options many years ago for bus topologies. However, bus networks work best with a limited number of devices. If more than a few dozen computers are added to a network bus, performance problems will likely result. In addition, if the backbone cable fails, the entire network effectively becomes unusable.

Ring Topology
In a ring network, every device has exactly two neighbors for communication purposes. All messages travel through a ring in the same direction (either "clockwise" or "counterclockwise"). A failure in any cable or device breaks the loop and can take down the entire network.



To implement a ring network, one typically uses FDDI, SONET, or Token Ring technology. Ring topologies are found in some office buildings or school campuses.

Star Topology
Many home networks use the star topology. A star network features a central connection point called a "hub" that may be a hub, switch or router. Devices typically connect to the hub with Unshielded Twisted Pair (UTP) Ethernet.



Compared to the bus topology, a star network generally requires more cable, but a failure in any star network cable will only take down one computer's network access and not the entire LAN. (If the hub fails, however, the entire network also fails.)

Tree Topology
Tree topologies integrate multiple star topologies together onto a bus. In its simplest form, only hub devices connect directly to the tree bus, and each hub functions as the "root" of a tree of devices. This bus/star hybrid approach supports future expandability of the network much better than a bus (limited in the number of devices due to the broadcast traffic it generates) or a star (limited by the number of hub connection points) alone.



Mesh Topology
Mesh topologies involve the concept of routes. Unlike each of the previous topologies, messages sent on a mesh network can take any of several possible paths from source to destination. (Recall that even in a ring, although two cable paths exist, messages can only travel in one direction.) Some WANs, most notably the Internet, employ mesh routing.



A mesh network in which every device connects to every other is called a full mesh. As shown in the illustration below, partial mesh networks also exist in which some devices connect only indirectly to others.
Summary
Topologies remain an important part of network design theory. You can probably build a home or small business computer network without understanding the difference between a bus design and a star design, but becoming familiar with the standard topologies gives you a better understanding of important networking concepts like hubs, broadcasts, and routes.

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