Wi-Fi Interview Preparation Guide
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Wi-Fi Interview Questions and Answers will guide us now that Wi-Fi is a trademark of the Wi-Fi Alliance that manufacturers may use to brand certified products that belong to a class of wireless local area network (WLAN) devices based on the IEEE 802.11 standards. Because of the close relationship with its underlying standard, the term Wi-Fi is often used as a synonym for IEEE 802.11 technology. So learn Wi-Fi and get job in Wi-Fi with the help of this Wi-Fi Interview Questions and Answers guide

31 Wi-Fi Questions and Answers:

1 :: What is Wi-Fi Technology?

A way to get Internet access, the term Wi Fi is a play upon the decades-old term HiFi that describes the type of output generated by quality musical hardware, Wi Fi stands for Wireless Fidelity and is used to define any of the wireless technology in the IEEE 802.11 specification - including (but not necessarily limited to) the wireless protocols 802.11a, 802.11b, and 802.11g. The Wi-Fi Alliance is the body responsible for promoting the term and its association with various wireless technology standards.

2 :: What does Free Wi-Fi really mean?

As the availability of Free Wi-Fi locations continues to spread I thought it might be good to review what Free might mean in different types of locations. The locations listed in the Wi-Fi Directory all offer some type of Free Wi-Fi access to the public, but sometimes there may be access requirements/restrictions that are unique to a particular type of location, and therefore the access, although free, may not be available to everyone/anyone. While accessing the Free Wi-Fi in certain locations you will be spending money to pay for a Hotel room or space in a RV Resort or for coffee in a cafe, etc. so the following information should help to clarify what Free Wi-Fi really means in different locations.

3 :: What can I do at a Wi-Fi?

The Wi-Fi wireless broadband connection allows you to do anything you'd do from home or the office. You can surf the Web, check your e-mail, connect to your Corporate network (be sure to use a secure VPN connection), make free Voice over IP phone calls, play online games, update your blog, and IM with your friends. If you just have a modem dial-up account at home you'll probably end up spending more time at the Wi-Fi once you see how much faster it is.

4 :: Is my data and e-mail secure at a Wi-Fi?

You should never conduct unsecured transactions that include any account or password information over public hotspots using FTP, email, or the Web. Try to use SSL for email (POP and SMTP), or read your email with a Web browser using an SSL connection. Ask your ISP if they offer SSL secure web-based email.

5 :: What is a Wi Fi Hotspot?

A Wi Fi hotspot is defined as any location in which 802.11 (wireless) technology both exists and is available for use to consumers. In some cases the wireless access is free, and in others, wireless carriers charge for Wi Fi usage. Generally, the most common usage of Wi Fi technology is for laptop users to gain Internet access in locations such as airports, coffee shops, and so on, where Wi Fi technology can be used to help consumers in their pursuit of work-based or recreational Internet usage.

6 :: How Can I Use Wi Fi?

You must be using a computer or PDA that has Wi Fi connectivity already working. Most portable computers can add Wi Fi using an adapter that plugs into a PC card slot or USB port.

7 :: Will I need to have an account with a Wi-Fi service provider?

Generally, no. You should be able to sign up with the provider at the location. Many providers will display instructions when browser software opens on a WiFi-enabled computer. If you don't have an account, simply start your computer and make sure your Wi Fi card is plugged on. Then, open a browser.

8 :: Is Wi Fi the same as Bluetooth?

No. While both are wireless technology terms, Bluetooth technology lives under the IEEE protocol 802.15.1, while Wi Fi falls under the 802.11 specification. What this means for consumers is that appliances using Wi Fi technology and those using Bluetooth technology are not interoperable. Bluetooth and Wi Fi are different in several ways, and are not necessarily in competition. Wi Fi technology boasts faster data transfer speeds and range, making it a good replacement for Ethernet (802.3) systems, while Bluetooth requires less power and is therefore more prominent in small appliances, such as PDAs.

9 :: What is the difference between wifi and mifi?

Wifi provides internet connectivity using wifi hotspots while mifi provides connectivity when the devices are moving. Refer such tutorials, terminologies and more on RFWireless-world.com

10 :: Define Piggybacking in context to Wi-Fi?

Piggybacking is a term which states that something that is riding on the back of something else to complete his/her motive, just like similar to an idiom putting gun to another's shoulder and performing the Hunting, so piggybacking is a term used to refer to access of a wireless internet connection by bringing one's own computer within the range of another's wireless connection, and using that service without the subscriber's explicit permission or knowledge. It is a legally and ethically controversial practice, with laws that vary in jurisdictions around the world. Piggybacking is an unauthorized tapping into another's connection with a public utility.
For e.g.- So piggybacking can be takes place like when I am accessing the wireless connection of my neighbor Wi-Fi without his/her knowledge by hacking his static ip address, then it would be possible for me to access the Wi-Fi connection of others.

11 :: Suppose if you are setting up three WLANs and want minimum interference over there then what are recommended channels?

There is a need of selecting the channels for setting up WLANs, to communicate; all the components of a Wi-Fi network must use the same channel. In the Wi-Fi network in infrastructure mode (using an access point), it depends on the channel set at the access point.
For better results when using Wi-Fi, it is necessary to adjust the channel on the access point as well as configured on the client, to take the least use channel in your neighborhood.
To do this you can use software such as NetStumbler, which will list the neighborhood Wi-Fi networks and channels used.

12 :: What are wifi recommended channels?

★ Channel 1: 2.412 MHz
★ Channel 2: 2.417 MHz
★ Channel 3: 2.422 MHz
★ Channel 4: 2.427 MHz
★ Channel 5: 2.432 MHz
★ Channel 6: 2.437 MHz
You can choose from these channels while setting up the WLANs.

13 :: Suppose if you are using WEP (Wired Equivalent Privacy) Password with backtrack then how you crack Wi-Fi network?

The first line of defense of your Wi-Fi network is encryption, which encodes the data transmitted between your PC and your wireless router.
WEP abbreviates for (Wireless Encryption Protocol) it is a less-secure protocol than WPA (Wireless Protected Access). Since WEP is relatively easy to crack, so you have to use the same form on all devices on your network. If you have an older router that supports WEP only you'll be best safest if you use 128-bit bit WEP keys but also check the manufacturer's Web site for a firmware update that will add WPA support.

Two of the most popular programs used for actually cracking the WEP key are Airsnort and Aircrack. Airsnort can be used with the .dump files that Kismet provides; and Aircrack can be use with .cap files that Airodump provides.

14 :: Can you please explain the difference between Ad-Hoc and Infrastructure topology?

Wireless networks typically work in one of two configurations: Ad-Hoc or Infrastructure.
Ad-Hoc is Latin meaning "for this purpose" so these are the networks which are basically created for some purpose. So these are the group of workstations which communicate directly witch each other to exchange information. An Ad-Hoc network is also called as a peer to peer network.

In Infrastructure mode, network includes an access point when the wireless clients connect to an access point, which in turn bridges to a network. Infrastructure network can pass information through a central information hub which can be both, hardware or software device on a computer. So under this devices in a wireless network are set up to communicate through an access point.

15 :: What are benefits of an Ad-Hoc network?

★ The possibilities with Ad-Hoc network are quite endless.
★ Ad-Hoc networks are simple to set up.
★ Ad-Hoc networks are inexpensive.
★ Ad-Hoc networks are fast.

16 :: What are disadvantages of an Ad-Hoc network?

★ It is not able to get into the mainstream wired local area network.
★ It needs more technology to support their reliability.
★ As the network increases its speed slows down considerably.

17 :: What are the benefits of infrastructure network?

★ In this you do not have to control over the path your data takes.
★ Connect to a wired network.
★ Extend your wireless network's range.
★ Utilize roaming ability.

18 :: What are the disadvantages of infrastructure network?

★ Use of more wireless access points.
★ This increase the cost of implementing a wireless network solution.

19 :: How to secure wireless network?

★ Verify that your PC's software firewall is turned on, and that Window's file-sharing feature is off; it's off by default in Window's XP with Service Pack 2.
★ Never send bank passwords, credit card numbers, confidential e-mail, or other sensitive data unless you're sure you're on secure site: Look for the lock icon in the bottom-right corner of your browser, as well as a URL in the address bar that begins with https. Such sites build in their own encryption.
★ Always turn your Wi-Fi radio off when you're not at a hotspot: Hackers can use it to create peer-to-peer Wi-Fi connections with your computer and access it directly.
★ For better security, consider signing up for a paid subscription to a hotspot network such as Boingo or T-Mobile. Both companies provide connection software that encrypts your sessions automatically.

20 :: What are the preferred tools for WarDriving?

★ Kismet- Kismet is a 802.11b wireless network sniffer. It is capable of sniffing using almost any wireless card supported in Linux.
★ Airsnort- is one of the first tools to come out discovering insecurity of wireless network. AirSnort is a wireless LAN (WLAN) tool which cracks encryption keys on 802.11b WEP networks. AirSnort operates by passively monitoring transmissions, computing the encryption key when enough packets have been gathered.
★ WEPCrack is Perl based tool. WEPCrack is a tool that cracks 802.11 WEP encryption keys using the latest discovered weakness of RC4 key scheduling.
★ WaveStumbler is console based 802.11 network mapper for Linux. It reports the basic AP stuff like channel, WEP, ESSID, MAC etc.
★ Aircrack yet another WEP cracking tool for Linux courtesy by divine.