How Routers Work ?

source : voipstuff.net

We're all used to seeing the various parts of the Internet that come into our homes and offices -- the Web pages, e-mail messages and downloaded files that make the Internet a dynamic and valuable medium. But none of these parts would ever make it to your computer without a piece of the Internet that you've probably never seen. In fact, most people have never stood "face to machine" with the technology most responsible for allowing the Internet to exist at all: the router.

When you send e-mail to a friend on the other side of the country, how does the message know to end up on your friend's computer, rather than on one of the millions of other computers in the world? Much of the work to get a message from one computer to another is done by routers, because they're the crucial devices that let messages flow between networks, rather than within networks.

Let's look at what a very simple router might do. Imagine a small company that makes animated 3-D graphics for local television stations. There are 10 employees of the company, each with a computer. Four of the employees are animators, while the rest are in sales, accounting and management. The animators will need to send lots of very large files back and forth to one another as they work on projects. To do this, they'll use a network.

When one animator sends a file to another, the very large file will use up most of the network's capacity, making the network run very slowly for other users. One of the reasons that a single intensive user can affect the entire network stems from the way that Ethernet works. Each information packet sent from a computer is seen by all the other computers on the local network. Each computer then examines the packet and decides whether it was meant for its address. This keeps the basic plan of the network simple, but has performance consequences as the size of the network or level of network activity increases. To keep the animators' work from interfering with that of the folks in the front office, the company sets up two separate networks, one for the animators and one for the rest of the company. A router links the two networks and connects both networks to the Internet.
Directing Traffic



One of the tools a router uses to decide where a packet should go is a configuration table. A configuration table is a collection of information, including:The router is the only device that sees every message sent by any computer on either of the company's networks. When the animator in our example sends a huge file to another animator, the router looks at the recipient's address and keeps the traffic on the animator's network. When an animator, on the other hand, sends a message to the bookkeeper asking about an expense-account check, then the router sees the recipient's address and forwards the message between the two networks.
Information on which connections lead to particular groups of addresses
Priorities for connections to be used
Rules for handling both routine and special cases of traffic

A configuration table can be as simple as a half-dozen lines in the smallest routers, but can grow to massive size and complexity in the very large routers that handle the bulk of Internet messages.

A router, then, has two separate but related jobs:
The router ensures that information doesn't go where it's not needed. This is crucial for keeping large volumes of data from clogging the connections of "innocent bystanders."
The router makes sure that information does make it to the intended destination.

In performing these two jobs, a router is extremely useful in dealing with two separate computer networks. It joins the two networks, passing information from one to the other and, in some cases, performing translations of various protocols between the two networks. It also protects the networks from one another, preventing the traffic on one from unnecessarily spilling over to the other. As the number of networks attached to one another grows, the configuration table for handling traffic among them grows, and the processing power of the router is increased. Regardless of how many networks are attached, though, the basic operation and function of the router remains the same. Since the Internet is one huge network made up of tens of thousands of smaller networks, its use of routers is an absolute necessity.

When you make a telephone call to someone on the other side of the country, the telephone system establishes a stable circuit between your telephone and the telephone you're calling. The circuit might involve a half dozen or more steps through copper cables, switches, fiber optics, microwaves andsatellites, but those steps are established and remain constant for the duration of the call. This circuit approach means that the quality of the line between you and the person you're calling is consistent throughout the call, but a problem with any portion of the circuit -- maybe a tree falls across one of the lines used, or there's a power problem with a switch -- brings your call to an early and abrupt end. When you send an e-mail message with an attachment to the other side of the country, a very different process is used.

Internet data, whether in the form of a Web page, a downloaded file or an e-mail message, travels over a system known as a packet-switching network. In this system, the data in a message or file is broken up into packages about 1,500 bytes long. Each of these packages gets a wrapper that includes information on the sender's address, the receiver's address, the package's place in the entire message, and how the receiving computer can be sure that the package arrived intact. Each data package, called a packet, is then sent off to its destination via the best available route -- a route that might be taken by all the other packets in the message or by none of the other packets in the message. This might seem very complicated compared to the circuit approach used by the telephone system, but in a network designed for data there are two huge advantages to the packet-switching plan.
The network can balance the load across various pieces of equipment on a millisecond-by-millisecond basis.
If there is a problem with one piece of equipment in the network while a message is being transferred, packets can be routed around the problem, ensuring the delivery of the entire message.



The Path of a Packet



If you have enabled Internet connection sharing between two Windows 98-based computers, you're using one of the computers (the computer with the Internet connection) as a simple router. In this instance, the router does so little -- simply looking at data to see whether it's intended for one computer or the other -- that it can operate in the background of the system without significantly affecting the other programs you might be running.The routers that make up the main part of the Internet can reconfigure the paths that packets take because they look at the information surrounding the data packet, and they tell each other about line conditions, such as delays in receiving and sending data and traffic on various pieces of the network. Not all routers do so many jobs, however. Routers come in different sizes. For example:
Slightly larger routers, the sort used to connect a small office network to the Internet, will do a bit more. These routers frequently enforce rules concerning security for the office network (trying to secure the network from certain attacks). They handle enough traffic that they're generally stand-alone devices rather than software running on a server.
The largest routers, those used to handle data at the major traffic points on the Internet, handle millions of data packets every second and work to configure the network most efficiently. These routers are large stand-alone systems that have far more in common with supercomputers than with your office server.



Routing Packets: An Example



In addition to routing packets from one point to another, the HowStuffWorks router has rules limiting how computers from outside the network can connect to computers inside the network, how the HowStuffWorks network appears to the outside world, and other security functions. While most companies also have a special piece of hardware or software called a firewall to enforce security, the rules in a router's configuration table are important to keeping a company's (or family's) network secure.Let's take a look at a medium-sized router -- the router we use in the HowStuffWorks office. In our case, the router only has two networks to worry about: The office network, with about 50 computers and devices, and the Internet. The office network connects to the router through an Ethernet connection, specifically a 100 base-T connection (100 base-T means that the connection is 100 megabits per second, and uses a twisted-pair cable like an 8-wire version of the cable that connects your telephone to the wall jack). There are two connections between the router and our ISP (Internet service provider). One is a T-1 connection that supports 1.5 megabits per second. The other is an ISDN line that supports 128 kilobits per second. The configuration table in the router tells it that all out-bound packets are to use the T-1 line, unless it's unavailable for some reason (perhaps a backhoe digs up the cable). If it can't be used, then outbound traffic goes on the ISDN line. This way, the ISDN line is held as "insurance" against a problem with the faster T-1 connection, and no action by a staff member is required to make the switch in case of trouble. The router's configuration table knows what to do.

One of the crucial tasks for any router is knowing when a packet of information stays on its local network. For this, it uses a mechanism called a subnet mask. The subnet mask looks like an IP address and usually reads "255.255.255.0." This tells the router that all messages with the sender and receiver having an address sharing the first three groups of numbers are on the same network, and shouldn't be sent out to another network. Here's an example: The computer at address 15.57.31.40 sends a request to the computer at 15.57.31.52. The router, which sees all the packets, matches the first three groups in the address of both sender and receiver (15.57.31), and keeps the packet on the local network. (You'll learn more about how the addresses work in the next section.)

Between the time these words left the Howstuffworks.com server and the time they showed up on yourmonitor, they passed through several routers (it's impossible to know ahead of time exactly how many "several" might be) that helped them along the way. It's very similar to the process that gets a postal letter from your mailbox to the mailbox of a friend, with routers taking the place of the mail sorters and handlers along the way.
Knowing Where to Send Data



When a friend mails a birthday card to be delivered to you at your house, he probably uses an address that looks something like this:Routers are one of several types of devices that make up the "plumbing" of a computer network. Hubs, switches and routers all take signals from computers or networks and pass them along to other computers and networks, but a router is the only one of these devices that examines each bundle of data as it passes and makes a decision about exactly where it should go. To make these decisions, routers must first know about two kinds of information: addresses and network structure.
Joe Smith 123 Maple Street Smalltown, FL 45678

The address has several pieces, each of which helps the people in the postal service move the letter along to your house. The ZIP code can speed the process up; but even without the ZIP code, the card will get to your house as long as your friend includes your state, city and street address. You can think of this address as a logical address because it describes a way someone can get a message to you. This logical address is connected to aphysical address that you generally only see when you're buying or selling a piece of property. The survey plot of the land and house, with latitude, longitude or section bearings, gives the legal description, or address, of the property.
Logical Addresses

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Every piece of equipment that connects to a network, whether an office network or the Internet, has a physical address. This is an address that's unique to the piece of equipment that's actually attached to the network cable. For example, if your desktop computer has a network interface card (NIC) in it, the NIC has a physical address permanently stored in a special memory location. This physical address, which is also called the MAC address (for Media Access Control) has two parts, each 3 bytes long. The first 3 bytes identify the company that made the NIC. The second 3 bytes are the serial number of the NIC itself.

The interesting thing is that your computer can have several logical addresses at the same time. Of course, you're used to having several "logical addresses" bring messages to one physical address. Your mailing address, telephone number (or numbers) and home e-mail address all work to bring messages to you when you're in your house. They are simply used for different types of messages -- different networks, so to speak.

Logical addresses for computer networks work in exactly the same way. You may be using the addressing schemes, or protocols, from several different types of networks simultaneously. If you're connected to the Internet (and if you're reading this, you probably are), then you have an address that's part of the TCP/IP network protocol. If you also have a small network set up to exchange files between several family computers, then you may also be using the Microsoft NetBEUI protocol. If you connect to your company's network from home, then your computer may have an address that follows Novell's IPX/SPX protocol. All of these can coexist on your computer. Since the driver software that allows your computer to communicate with each network uses resources like memory and CPU time, you don't want to load protocols you won't need, but there's no problem with having all the protocols your work requires running at the same time.

How WiFi Works ?

source : tonbridges.com

If you've been in an airport, coffee shop, library or hotel recently, chances are you've been right in the middle of a wireless network. Many people also use wireless networking, also called WiFi or 802.11 networking, to connect their computers at home, and some cities are trying to use the technology to provide free or low-cost Internet access to residents. In the near future, wireless networking may become so widespread that you can access the Internet just about anywhere at any time, without using wires.

WiFi has a lot of advantages. Wireless networks are easy to set up and inexpensive. They're also unobtrusive -- unless you're on the lookout for a place to watch streaming movies on your tablet, you may not even notice when you're in a hotspot. In this article, we'll look at the technology that allows information to travel over the air. We'll also review what it takes to create a wireless network in your home.

First, let's go over a few WiFi basics.



What Is WiFi?

A wireless network uses radio waves, just like cell phones, televisions and radios do. In fact, communication across a wireless network is a lot like two-way radio communication. Here's what happens:
A computer's wireless adapter translates data into a radio signal and transmits it using an antenna.
A wireless router receives the signal and decodes it. The router sends the information to the Internet using a physical, wired Ethernet connection.

The process also works in reverse, with the router receiving information from the Internet, translating it into a radio signal and sending it to the computer's wireless adapter.

The radios used for WiFi communication are very similar to the radios used for walkie-talkies, cell phones and other devices. They can transmit and receive radio waves, and they can convert 1s and 0sinto radio waves and convert the radio waves back into 1s and 0s. But WiFi radios have a few notable differences from other radios:
They transmit at frequencies of 2.4 GHz or 5 GHz. This frequency is considerably higher than the frequencies used for cell phones, walkie-talkies and televisions. The higher frequency allows the signal to carry more data.
They use 802.11 networking standards, which come in several flavors:
802.11a transmits at 5 GHz and can move up to 54 megabits of data per second. It also usesorthogonal frequency-division multiplexing (OFDM), a more efficient coding technique that splits that radio signal into several sub-signals before they reach a receiver. This greatly reduces interference.
802.11b is the slowest and least expensive standard. For a while, its cost made it popular, but now it's becoming less common as faster standards become less expensive. 802.11b transmits in the 2.4 GHz frequency band of the radio spectrum. It can handle up to 11 megabits of data per second, and it usescomplementary code keying (CCK) modulation to improve speeds.
802.11g transmits at 2.4 GHz like 802.11b, but it's a lot faster -- it can handle up to 54 megabits of data per second. 802.11g is faster because it uses the same OFDM coding as 802.11a.
802.11n is the most widely available of the standards and is backward compatible with a, b and g. It significantly improved speed and range over its predecessors. For instance, although 802.11g theoretically moves 54 megabits of data per second, it only achieves real-world speeds of about 24 megabits of data per second because of network congestion. 802.11n, however, reportedly can achieve speeds as high as 140 megabits per second. 802.11n can transmit up to four streams of data, each at a maximum of 150 megabits per second, but most routers only allow for two or three streams.
802.11ac is the newest standard as of early 2013. It has yet to be widely adopted, and is still in draft form at the Institute of Electrical and Electronics Engineers (IEEE), but devices that support it are already on the market. 802.11ac is backward compatible with 802.11n (and therefore the others, too), with n on the 2.4 GHz band and ac on the 5 GHz band. It is less prone to interference and far faster than its predecessors, pushing a maximum of 450 megabits per second on a single stream, although real-world speeds may be lower. Like 802.11n, it allows for transmission on multiple spatial streams -- up to eight, optionally. It is sometimes called 5G WiFi because of its frequency band, sometimes Gigabit WiFibecause of its potential to exceed a gigabit per second on multiple streams and sometimes Very High Throughput (VHT) for the same reason.
Other 802.11 standards focus on specific applications of wireless networks, like wide area networks (WANs) inside vehicles or technology that lets you move from one wireless network to another seamlessly.
WiFi radios can transmit on any of three frequency bands. Or, they can "frequency hop" rapidly between the different bands. Frequency hopping helps reduce interference and lets multiple devices use the same wireless connection simultaneously.

As long as they all have wireless adapters, several devices can use one router to connect to the Internet. This connection is convenient, virtually invisible and fairly reliable; however, if the router fails or if too many people try to use high-bandwidth applications at the same time, users can experience interference or lose their connections. Although newer, faster standards like 802.11ac could help with that.

Next, we'll look at how to connect to the Internet from a WiFi hotspot.



WiFi Hotspots

A WiFi hotspot is simply an area with an accessible wireless network. The term is most often used to refer to wireless networks in public areas like airports and coffee shops. Some are free and some require fees for use, but in either case they can be handy when you are on the go. You can even create your own mobile hotspot using a cell phone or an external device that can connect to a cellular network. And you can always set up a WiFi network at home.

If you want to take advantage of public WiFi hotspots or your own home-based network, the first thing you'll need to do is make sure your computer has the right gear. Most new laptops and many new desktop computers come with built-in wireless transmitters, and just about all mobile devices are WiFi enabled. If your computer isn't already equipped, you can buy a wireless adapter that plugs into the PC card slot or USB port. Desktop computers can use USB adapters, or you can buy an adapter that plugs into the PCI slot inside the computer's case. Many of these adapters can use more than one 802.11 standard.

Once you've installed a wireless adapter and the drivers that allow it to operate, your computer should be able to automatically discover existing networks. This means that when you turn your computer on in a WiFi hotspot, the computer will inform you that the network exists and ask whether you want to connect to it. If you have an older computer, you may need to use a software program to detect and connect to a wireless network.

Being able to connect to the Internet in public hotspots is extremely convenient. Wireless home networks are convenient as well. They allow you to easily connect multiple computers and to move them from place to place without disconnecting and reconnecting wires. In the next section, we'll look at how to create a wireless network in your home.



Building a Wireless Network

If you already have several computers networked in your home, you can create a wireless network with awireless access point. If you have several computers that are not networked, or if you want to replace your Ethernet network, you'll need a wireless router. This is a single unit that contains:
A port to connect to your cable or DSL modem
A router
An Ethernet hub
A firewall
A wireless access point

A wireless router allows you to use wireless signals or Ethernet cables to connect your computers and mobile devices to one another, to a printer and to the Internet. Most routers provide coverage for about 100 feet (30.5 meters) in all directions, although walls and doors can block the signal. If your home is very large, you can buy inexpensive range extenders or repeaters to increase your router's range.

As with wireless adapters, many routers can use more than one 802.11 standard. Normally, 802.11b routers are slightly less expensive than others, but because the standard is older, they're also slower than 802.11a, 802.11g, 802.11n and 802.11ac routers. 802.11n routers are the most common.

Once you plug in your router, it should start working at its default settings. Most routers let you use a Web interface to change your settings. You can select:
The name of the network, known as its service set identifier (SSID) -- The default setting is usually the manufacturer's name.
The channel that the router uses -- Most routers use channel 6 by default. If you live in an apartment and your neighbors are also using channel 6, you may experience interference. Switching to a different channel should eliminate the problem.
Your router's security options -- Many routers use a standard, publicly available sign-on, so it's a good idea to set your own username and password.

Security is an important part of a home wireless network, as well as public WiFi hotspots. If you set your router to create an open hotspot, anyone who has a wireless card will be able to use your signal. Most people would rather keep strangers out of their network, though. Doing so requires you to take a few security precautions.

It's also important to make sure your security precautions are current. The Wired Equivalency Privacy (WEP) security measure was once the standard for WAN security. The idea behind WEP was to create a wireless security platform that would make any wireless network as secure as a traditional wired network. But hackers discovered vulnerabilities in the WEP approach, and today it's easy to find applications and programs that can compromise a WAN running WEP security. It was succeeded by the first version of WiFi Protected Access (WPA), which uses Temporal Key Integrity Protocol (TKIP) encryption and is a step up from WEP, but is also no longer considered secure.

To keep your network private, you can use one or both of the following methods:
WiFi Protected Access version 2 (WPA2) is the successor to WEP and WPA, and is now the recommended security standard for WiFi networks. It uses either TKIP or Advanced Encryption Standard (AES) encryption, depending upon what you choose at setup. AES is considered the most secure. As with WEP and the initial WPA, WPA2 security involves signing on with a password. Public hotspots are either open or use any of the available security protocols, including WEP, so use caution when connecting away from home. WiFi Protected Setup (WPS), a feature that ties a hard-coded PIN to the router and makes setup easier, apparently creates a vulnerability that can be exploited by hackers, so you may want to turn off WPS if possible, or look into routers that do not have the feature.
Media Access Control (MAC) address filtering is a little different from WEP, WPA or WPA2. It doesn't use a password to authenticate users -- it uses a computer's physical hardware. Each computer has its own unique MAC address. MAC address filtering allows only machines with specific MAC addresses to access the network. You must specify which addresses are allowed when you set up your router. If you buy a new computer or if visitors to your home want to use your network, you'll need to add the new machines' MAC addresses to the list of approved addresses. The system isn't foolproof. A clever hacker can spoof a MAC address -- that is, copy a known MAC address to fool the network that the computer he or she is using belongs on the network.

You can also change other router settings to improve security. For instance, you can set it to block WAN requests to keep the router from responding to IP requests from remote users, set a limit to the number of devices that can connect to your router and even disable remote administration so that only computers plugged directly into your router can change your network settings. You should also change the Service Set Identifier (SSID), which is your network name, to something other than the default so that hackers can't immediately tell what router you are using. And selecting a strong password never hurts.

Wireless networks are easy and inexpensive to set up, and most routers' Web interfaces are virtually self-explanatory. For more information on setting up and using a wireless network, check out the links on the next page.



Lots More Information

Author's Note: How WiFi Works -- Bernadette Johnson

I worked on an update to the content of this article, and I think it's amazing that in a few scant years we've gone from mostly wired to mostly wireless data transfer, via WiFi in our homes and public places, as well as cell phones. Of course, a lot of the infrastructure still uses wires, but the fact that we can communicate via both radio waves and electricity traveling through wires is pretty incredible. A big thanks to the inventors of the telegraph and every communication innovation that came after.

I remember the days when most mere mortals didn't have modems and couldn't get on the net, even if they had computers. Perhaps I'm projecting my experiences onto everyone else, but when I was a kid, our computer was this tool we used in isolation, save for the times friends would come over to play video games. My computer programmer aunt was the only person I knew who had a modem. It was the type where you put your phone directly onto a cradle and some crazy analog communication went on.

When modems became widespread, they were still these clunky external things that we hooked up to our computers to noisily and slowly dial up to a larval Internet. They tied up the phone line, so you couldn't keep them connected indefinitely, and if you didn't want to run up an astronomical phone bill you had to make sure you were using a phone number for a local access point. Modems went internal and got a bit faster, but now dial-up is going the way of the dodo bird due to the ubiquity of affordable broadband services in the home like DSL and cable.

With an astounding jump in bandwidth, and the ability of our computers to connect wirelessly, many of us are online all the time, and free to compute all over the house or even away from home. I've surfed the net, streamed shows and downloaded books while on vacation via hotel, airport and other hotspots. And I fall asleep nightly streaming Netflix on my WiFi-only tablet at home. Which is great, aside from the fact that I really should be resting. But insomnia and information overload are topics for another time.

How to Detect if Someone's Stealing Your WiFi ?

source : icon finder.com

It may be hard to imagine, but just a mere 20 years ago, the Internet was nothing more than a novelty -- a way for incredibly smart college professors and researchers to share information, and for a few people to network across the newly developed World Wide Web. E-mail was nothing like it is today. The primitive e-mail systems found at universities or even through accounts offered with the first Internet service providers (ISPs) such as Prodigy and America Online were often difficult to use.

Fast forward to the 2010s and things have changed significantly. Where wired Internet once kept us tethered to a desk, today's laptops and mobile devices give us access to friends and endless entertainment practically anywhere via WiFi, 3G and 4G technologies.

While we use 3G and 4G data on our smartphones as we're out and about in the world, WiFi still dominates in the home. And in coffee shops. And libraries. And airports. Thanks to the ubiquity of wireless routers and hotspots, just about any plain old wired Internet connection -- faster and cheaper and without the limiting bandwidth caps of cellular data -- can be turned into a convenient WiFi zone.

Whether we install them ourselves or get them from our Internet providers, most of us have WiFi routers in our homes these days. That can cause a couple of problems: When wireless signals are operating on the same frequency, they can cause interference, especially if you're living in an apartment building. And without the proper security, someone could easily hop onto your wireless network.

Chances are you're reading this article because you suspect someone is piggybacking or using your WiFi without your permission. When wireless squatters steal your WiFi, they eat up your bandwidth. In extreme cases, they may even steal information off your computer or infect machines on your network with a virus. But fear not: It's easy to fight back. Let's start with a basic overview of managing a wireless network, which is the first step towards keeping your WiFi setup nice and secure.


Understanding Your WiFi Network

Before you can detect if someone is ripping off your wireless Internet connection, it's important to understand some basic computer networking lingo. For more information on how to set up a wireless network, take a look at How WiFi Works. Now, let's look at a few of the areas in a wireless network that will give you a baseline for determining if your WiFi signal is being sapped unexpectedly.

A wireless network is comprised of a broadband Internet connection from a DSL, cable or satellite modem. You attach the modem to the wireless router, which distributes the signal and creates a network.

This is what's called a local area network (LAN). This LAN is where you set up computer peripherals such as your desktop or laptop computer and printer. Your router will have what's called a dynamic host client protocol (DHCP) table. In essence, your DHCP table is your guest list of every allowed piece of computing equipment.

Each device has its own media access control(MAC) address. Think of this as its signature. Your router uses these addresses to assign each machine on your network an Internet protocol (IP) address. The MAC and IP addresses of your equipment will be useful in a moment when we look at ways to detect whether or not someone is stealing your WiFi. For a more in-depth understanding of IP addresses, read What is an IP address?

There are also a couple of important terms related to WiFi that you should know. A service set identifier (SSID) is the name that identifies a wireless network. By default, this will probably be the name of your router -- Netgear or ASUS or something similar -- but you can have fun by changing it to something more personal or creative, like Abraham Linksys. Today's most commonly used WiFi speed, 802.11n, is capable of up to 600 megabit per second data transfers. 802.11ac is the next standard, which will allow for wireless speeds of over one gigabit per second. 2.4GHz and 5GHz are two different wireless frequencies used in wireless routers.

If you're confused by some of this computer rhetoric, don't be. What's important is that you know what to look for when we get ready to diagnose your WiFi connection. Speaking of which, let's get to it in the next section. After all, that's what you came here for.





Setting up a Secure Network



There's only one thing you need to prevent 99.9 percent of wireless squatters from using your Internet connection: a password.Okay, it's time to get down to it. Is your wireless network running slowly? Do you have intermittent losses in Internet access and you can't figure out why? First, take a breath. In all likelihood, no one is stealing your Internet. Tons of things could cause a slow connection. Your Internet service provider might be having issues or is overloaded with traffic. Your WiFi router might be experiencing interference from other electronics, or simply be having trouble penetrating the walls and furniture of your home to get a wireless signal to your computer.

The most basic element of wireless security is an encryption protocol such as WPA2, or WiFi Protected Access. Older standards like WEP and the first generation of WPA have been phased out for the more secure WPA2. You don't need to know anything about how the encryption works -- you just need to set up WPA2 security on you wireless router and set a password for the network. Make it something you can remember that's not easy for others to guess (please don't use "password" or "12345!") and you'll be well on your way to security.

So how do you do all of that? Well, that varies by the type of router you have, but most WiFi routers are accessible from a connected device via the address http://192.168.1.1 in a Web browser. Logging in is usually easy, too, as most router manufacturers use a simple pair of words like "root" and "admin" for the device's login and password (you should be able to find this information in the manual). That will take you to a management tool where you can change all kinds of settings, including your wireless security.

That tip might set off a little security alert in the back of your head. "Wait, a minute," you think. "If most routers use the same local address and login/password, couldn't anyone get in there and mess with my security settings?" Well ... yes! Without a password, your wireless network is open for anyone to hop on. But a password isn't quite all you need to be totally secure. You should also change the router's login information to something aside from the usual "admin." That will keep virtually everyone from messing with your router -- but let's take a look at how to detect a WiFi leach, just in case.






Detecting Wireless Piggybacking

With WPA2 security enabled, it's unlikely anyone will ever piggyback on your network. But there's an easy way to spot squatters: Since every device connected to your network has a unique IP address and MAC address, you can easily see a list of connected devices -- often listed as "clients" -- on one of the settings pages for your wireless router. Many devices broadcast an ID because they've been named by their owners, so if you see "John's Laptop" connected to your network and you don't have a John in the house, you've found trouble! Even if a device doesn't show a name in the router's client list, you can count the number of devices connected and compare to the number of devices you know should be there to see if the numbers are off.

Want to make absolutely sure no one's going to figure out your password and worm their way onto your network? You have a few options. Your router can hide its SSID, meaning it won't show up for anyone searching for connectable networks. The address will have to be entered manually. You can also set up a wireless MAC filter to "whitelist" devices you own, disabling access for anyone else. Of course, this makes it a bit tougher for welcome guests, such as friends, to get online at your house.

Internet monitoring software is also an option. For example, free utility AirSnare will alert you when unfamiliar MAC addresses log onto your network. But with a secure connection, you shouldn't have to worry about that. The truth is, WiFi is not a precious commodity like it once was. You can get it at practically any coffee shop. Millions of us carry around smartphones with always-on data connections. To some degree, that makes WiFi access a faster, cheaper option of Internet access, but it's not always the most convenient one.

As long as your network is passworded, only a hacker using specialized software is going to get past your security. Technology site Ars Technica has detailed how a $2500 program called Silica can be used in conjunction with Web sites containing dictionaries of millions of words to connect to a secured network and crack its password [source: Ars Technica]. But there's still an easy way to stop even serious hackers in their tracks: Use a better password. The longer and harder to guess, the safer your network will be.

With a strong password, you shouldn't ever have to worry about keeping tabs on who connects to your network. Piggybackers will have to find someone else to mooch off of.




Lots More Information

Author's Note

Smartphones changed everything, didn't they? A few short years ago, we hoarded WiFi like a precious commodity. Your neighbors might steal it! Criminals might park outside your house and download illegal files on your network! Sounds horrifying, doesn't it? Well, once we got smartphones with omnipresent data connections, we calmed down a bit. WiFi is now so ubiquitous that you don't have to worry too much about you neighbors leeching off of you -- they've probably got WiFi, too. We don't need to find hotspots when we've got 3G and 4G on our phones. Updating this article, it was amazing to see how much our Internet access has changed in a few short years. And wireless security is a lot better, too -- the article's old mentions of WEP felt archaic in a much more secure WPA2 world. In a few years, someone will no doubt look back on my update revision and say "WPA2? How quaint!"

How Electric Motors Work ?

source : google images

Electric motors are everywhere! In your house, almost every mechanical movement that you see around you is caused by an AC (alternating current) or DC (direct current) electric motor.

A simple motor has six parts:

• Armature or rotor
• Commutator
• Brushes
• Axle
• Field magnet
• DC power supply of some sort

By understanding how a motor works you can learn a lot about magnets, electromagnets and electricity in general. In this article, you will learn what makes electric motors tick.

Why are Web addresses in English?

source : gooogle images

The short answer: Web addresses are in English because the people who developed the standards for Web addresses were, for the most part, English-speaking Americans.

The longer answer: In the earliest days of the Internet, the only way to connect with a remote computer was to provide its unique IP address, a long string of digits such as 165.254.202.218. But in 1983, as the number of computers on the network continued to grow, the University of Wisconsin developed the Domain Name System (DNS), which maps numeric IP addresses to more easily remembered domain names like howstuffworks.com.

In 1990, British scientist (and English speaker) Tim Berners-Lee invented theWorld Wide Web, and by 1992, more than one million computers were connected, most of them in the United States [source: Computer History Museum]. In 1994, the Internet Engineering Task Force (IETF), a standards organization made up of representatives from several U.S. government agencies, published a set of standards for Web addresses, which it called Uniform Resource Locators, or URLs [sources: Berners-Lee, Internet Society, Ishida].

To make Web addresses easy to read, write, type and remember, the IETF restricted URLs to a small number of characters, namely the uppercase and lowercase letters of the English (or Latin) alphabet, the digits 0 through 9 and a few symbols [source: Berners-Lee]. The allowable characters are based on the American Standard Code for Information Exchange, better known as the US-ASCII character set, which was developed in the United States and first published in 1963.

This all worked out fine for English-speaking countries, but as of 2009, more than half of the 1.6 billion Internet users worldwide spoke a language with a character set other than the English (or Latin) alphabet [source: Whitney]. To understand what using the Web is like for those individuals, imagine that you have to navigate the Web using only Arabic. The content on your favorite sites is still in English, but the Web address for every site you use is made up of completely unfamiliar characters that may not even be found on your keyboard [source: Ishida]. That scenario, in reverse, is essentially what the Internet experience has been like for Web users who read and write using not only another language, but an entirely different alphabet or set of characters. (Visit a website like Egypt's el-balad.com, for example, and the distinction between the site content, which is entirely in Arabic, and the Web address, which uses only English characters, becomes immediately clear.)

Given the growing number of non-English users online, it may come as no surprise that English Web addresses are no longer the law of the land. In 2009, ICANN, the U.S.-based nonprofit organization that regulates domain names on the Internet, approved the use of Internationalized Domain Names (IDNs), meaning that Web addresses would be able to contain non-English characters like Chinese, Korean, Arabic or Cyrillic script [sources: Arthur, ICANN].

AVG partners with ZTE to bring security to mobile devices

source : engadget.com

Mobile security is starting to get attention, but still doesn't garner the same amount as the computer does. That doesn't mean it shouldn't be a concern, only that the average user isn't looking at it that way. However, we're starting to see that landscape slowly changing, with phones coming with built-in security software.

The latest will be devices from Chinese manufacturer ZTE, as the company has partnered with security firm AVG, which has long offered mobile apps to protect consumers.


"For many of us, our smartphones have become the primary device that we spend most time with, but ensuring mobile security can sometimes be an afterthought,” says Wang Xuemei, Business Manager at ZTE. "Our customers will be able to rely on our partnership with AVG to help take the worry out of connecting to their favorite websites, apps and using online services through their ZTE smartphones and tablets. We are committed to mobile security and strive to provide the best mobile experience possible to all of our users".

ZTE customers will get a free 60-day trial of the AVG Pro version, which they can elect to keep after that time, though a fee is involved. If they choose not to keep it, then it will default to the free version that has a few less features, but still should keep them safe.

"As we focus on helping to secure people, devices, and data across the globe, this partnership will ensure that new and existing mobile users have peace of mind by being protected from the outset, whether simply enjoying their favorite games or using useful online tools for banking or shopping" says AVG's David Ferguson.

No word was given about when phones will begin shipping with AVG pre-installed, but it likely won't take too long.

source : betanews.com

Cisco announces new embedded security solutions

source : wikipedia.id

Networking specialist Cisco is announcing new products to provide embedded enterprise security from the data center out to endpoints, branch offices and the cloud.

The company used this week's Cisco Live conference to announce that it's adding more sensors to increase visibility; more control points to strengthen enforcement; and pervasive, advanced threat protection to reduce time-to-detection and time-to-response, limiting the impact of attacks.


Cisco expects the Internet of Everything (IoE) to be worth $19 trillion over the next decade while the cybercrime sector could be worth up to $1 trillion.

Cisco's solutions include endpoint protection using its AnyConnect 4.1 VPN client which allows customers to easily deploy and significantly expand their threat protection to VPN-enabled endpoints to continuously and retrospectively guard against advanced malware.

Branch office protection is provided by FirePOWER Services solutions for Cisco Integrated Services Routers (ISR), offering centrally managed Next-Generation Intrusion Prevention System (NGIPS) and Advanced Malware Protection (AMP) where a dedicated security appliance may not be feasible.

Cisco will also add embedded multiple security technologies into the network infrastructure to provide broad threat visibility, to identify users and devices associated with anomalies, threats and misuse of networks and applications.

It's integrated StealthWatch with its Identity Services Engine to spot and block suspicious network devices and added NetFlow monitoring to offer greater insights into network traffic.

"To protect against today's threats and increase agility for organizations to seize new growth opportunities and implement new technologies, security must be pervasively embedded across the entire network infrastructure," says David Goeckeler, Senior Vice President and General Manager of Cisco's Security Business Group. "By integrating 'Security Everywhere' throughout the extended network and through cloud-delivered services, Cisco is protecting a wider array of attack vectors. This also provides enterprises and service providers with the confidence that they have the continuous and retrospective visibility and control to support new technologies and business opportunities in the Internet of Everything and the Digital Economy".

You can find out more about Cisco's ability to secure extended networks on the company's blog.