Interview Questions.

Question 1. What Are The Different Modes Of An Access Point (ap) Operation?

Answer :

An AP can be executed by this sort of modes of operation:

Root Mode— This is the actual AP mode. It can associate wireless clients and bridge the site visitors to the wired network while wished.
Bridge Mode— AP acts as a bridge and may be used to connect wired networks at a distance.
Repeater Mode— When the Ethernet port is disabled, the AP turns into a repeater and buddies to a close-by root AP.
Work Group Mode— A Workgroup Bridge (WGB) can provide a wi-fi infrastructure connection for Ethernet-enabled devices. Devices that don't have a wi-fi customer adapter to be able to connect with the wi-fi network may be linked to the WGB thru the Ethernet port. The WGB associates to the root AP via the wireless interface.
Question 2. Where Can I Download The Latest Firmware, Drivers, And Software For My Wireless Network?

Answer :

Cisco AirNet gadget operates fine when all additives are loaded with the most modern-day model of the software

Due to United States export compliance rules, you have to be registered on Cisco.Com to down load wireless software program. Registration is loose.

Wireless Interview Questions
Question 3. What Cisco Air Net Products Are Wi-fi Certified?

Answer :

Refer to Wi-Fi Certified Products leavingcisco.Com for cutting-edge certification information.

Question four. How Does Roaming Work? Who Roams When There Is Not Enough Signal Strength, The Client Or The Ap?

Answer :

Roaming is an set of rules applied and managed with the aid of the patron adapter and it is not described with the aid of IEEE standards. The roaming functionality is based totally on signal excellent, no longer just the proximity to the AP. Each seller has their own common sense to put into effect roaming.

For Cisco clients, roaming is because of any such events:

Maximum records retry remember is surpassed
Missed too many beacons
Data rate shift
Initial startup
Periodic consumer c program languageperiod (if configured)
Wireless Security Tutorial
Question five. What Is Fast Roaming?

Answer :

Fast roaming is a feature wherein the purchaser's credentials aren't sent to the Authentication server each time the client authenticates. Once a patron authenticates to an AAA server, credentials are cached inside the AP. The next time a consumer roams; the AP authenticates and elements the credentials through itself to the patron without sending it back to the AAA server. This saves time and enables faster roams of clients.

CWNA (Certified Wireless Network Administrator) Interview Questions
Question 6. Can The Radios Be Damaged If They Are Operated Without The Antennas Attached?

Answer :

Some radio system manufacturers specifically warn against this as it damages the transmitter. Most pieces of beginner or business radio device deliver this caution because they function at a much higher transmitter electricity. The meditated wave status wave ratio (SWR) caused by the shortage of a right antenna or load can damage the very last amplifier stage called the power amplifier (PA).

For Cisco AirNet device, the transmitter power output is one hundred mW for the 350 series and 30 mW for the 340 collection, so harm is unlikely but feasible. If you really have a demand to run the devices without antennas, it's miles endorsed that you switch the transmitter energy all the way down to 1-5 mW or use a 50-fifty two ohm "dummy load," just to be secure.

Warning: Never join the antenna port of one device immediately into the antenna port of some other device considering this will harm the devices.

Question 7. What Are All The Authentication Mechanisms Currently Supported By Cisco Access Points (aps)?

Answer :

This is a listing of authentication mechanisms currently supported:

WEP
WPA- Personal and WPA2-Personal
WPA-Enterprise and WPA2-Enterprise
EAP authentication
MAC authentication
Wireless Communication Tutorial BREW (Binary Runtime Environment for Wireless) Interview Questions
Question 8. Do I Need A License To Operate Wlans?

Answer :

WLAN device operates in a 2.Four GHz and 5 GHz frequency spectrum which might be license loose. In america, unfold spectrum gadgets fall beneath Federal Communications Commission (FCC) Part 15 of the policies that govern unlicensed devices. However, other international locations might require a license in case you function devices which are in part or absolutely exterior, which includes point-to-factor bridges. In addition, a few international locations would possibly require the gadget importer to achieve a telecommunications license to sell the product.

Question 9. Can I Use My Wireless Device On An Aircraft?

Answer :

Under present day Federal Aviation Administration (FAA) guidelines, using wireless gadgets on an plane is authorized if the plane is parked at the gate and the door is open, and if usage is allowed inside the airport. The tool must now not intrude with flight operation system which include navigation radar, communications, or emergency services.

The use of wi-fi gadgets on an aircraft with the door closed, whether it's miles sitting on the gate, taxiing, or in flight, is prohibited through the FAA and different Civil Aviation Agencies global. Wireless gadgets used at the aircraft (when the door is open on the gate) ought to meet the requirements of the local us of a employer or were granted a waiver by using the company or airport authority.

Wireless gadgets which are saved on the aircraft for use on the gate have to meet certification requirements for the u . S . A . That the neighborhood carrier is flagged for, and ought to be able to function within the frequency band of the host country, unless a waiver is granted to the system user. It is the duty of the device installer to reap all licenses and frequency or utilization waivers.

Wireless Testing Interview Questions
Question 10. What Is Channel Interference?

Answer :

When radios on a couple of get admission to factors share the same channel or nearby channel, then the frequency band overlaps with different gadgets. The facts transmitted is lost if there is any channel interference.

Question 11. What Is World Mode?

Answer :

Generally a wi-fi client can operate only in its Local Regulatory area as channel and electricity settings convey for each domain. When World Mode is used, a customer can routinely regulate channel and energy settings consistent with the area it migrates to. For example, if a consumer travels from the US to Japan a purchaser card that implements World Mode can robotically alter its channel and energy settings as in keeping with the Japan area. The get right of entry to factor (AP) should also support World Mode for this to paintings. The Cisco patron card and AP help World Mode.

Wireless Security Interview Questions
Question 12. Are The Wlan Cards Safe To Use From A Health Perspective Since They Use Microwave Frequencies?

Answer :

The WLAN gadgets are safe when used under normal working situations as stated inside the user manuals. The strength levels are under the electricity degree of a regular microwave oven. The radio modules have been tested by means of independent test labs in accordance with numerous diagnosed standards. The stages measured whilst the PCMCIA antenna changed into 1 cm faraway from the user had been recorded at 10-12% of the maximum level allowed.

Wireless Interview Questions
Question thirteen. The Fcc Limits The Maximum System Power To four Watts Effective Isotropic Ally Radiated Power (eirp) For Non Point-to-point Systems. However, A Properly Tested And Certified System Is Allowed To Exceed The four Watt Eirp For A Point-to-point System. I Have Two Parabolic Dishes Aimed At An Omni. Can I Exceed The 4 Watt Eirp Limit If I Consider Each Leg Point-to-factor?

Answer :

No. The FCC defines the gadget that makes use of directional benefit antennas as only a part of the entire gadget. You cannot exceed the 4W EIRP for any of the legs of this machine for the reason that entire gadget is a point-to-multipoint. This topic is described in FCC docket 96-eight, which covers the spread spectrum transmitter.

Question 14. My Wlan System Sees Radio Frequency Interference (rfi) Or Electromagnetic Interference (emi) From Another Device. What Can I Do?

Answer :

Relocate the Cisco AirNet device as a ways away as practical from ability sources of EMI/RFI or reorient the point-to-point antennas away from the RFI/EMI emitter.

Use a special frequency range for the phone and WLAN.

It is usually recommended which you perform a website survey before you install a WLAN. In website survey you can hit upon all varieties of interference sources. This consists of non-802.11 assets which include microwave ovens, cordless phones, and so on. You can collect facts on key parameters together with Signal energy, Noise, and Data quotes that exist within the real deployment state of affairs. Based in this, WLANs can be deliberate and deployed as a result.

Question 15. Would The Frequency Hopping (fh) Equipment Of Another Vendor That Sits Next To Our Direct Sequence (ds) Equipment Have Any Negative Effect?

Answer :

Yes. By its very nature, an FH product hops throughout the whole 2.Four frequency band. Therefore, it reasons interference to WLAN 802.Eleven b/g merchandise that perform in 2.Four GHz. There is no way to control in which an FH unit hops. 

Try one or all of these steps:

Change the region of the access factor and/or the bottom of the cordless smartphone.
Switch to channel 1 at the access factor. If that does not paintings, try channel 11.
Use a faraway antenna at the customer card if it's miles a PCI- or ISA-primarily based card and you've that choice.
Operate the phone with the antenna lowered, if this is an option.
If all else fails, use a 900-MHz phone instead of a 2.4-GHz smartphone.
Wireless Sensor Networks Interview Questions
Question 16. My Wlan System Sees Interference From A Cordless Phone. What Can I Do?

Answer :

Most cordless telephones function in 2.4 GHz and are every other important supply of interference.

Question 17. What Is The Maximum Speed Of 802.11 A,b,g Standards?

Answer :

802.11b has a maximum velocity of eleven Mbps at the same time as 802.11g and 802.11a have 54 Mbps.

Wireless Communication Interview Questions
Question 18. Does Cisco Currently Support 802.11n?

Answer :

Yes. Cisco helps 802.11n. However, 802.11n is supported best in 1250 collection APs currently.

CWNA (Certified Wireless Network Administrator) Interview Questions
Question 19. What Antenna Should I Use For The Cisco Air Net 1010 Access Point?

Answer :

This tool has a constructed in antenna. You do no longer need to connect an antenna.

The Cisco AirNet Antenna Reference Guide has all the facts approximately the distinctive sorts of antennas and add-ons that Cisco affords as part of the Cisco WLAN solution.

Question 20. I Have An Access Point About 50 Feet Away From My Client. The Signal Is Very Weak And There Is Significant Interference In The Path (paper Storage). What Should I Do To Obtain Proper Coverage?

Answer :

Install a high gain antenna for greater transmission and reception in order that the signal at a longer distance can be picked up without problems.

Question 21. What Type Of Antennas Should I Use For Bridges?

Answer :

There are one of a kind forms of external antennas which are designed for external uses most effective. Choose one in all them as in line with the character requirement (Yagi, Dish, and so on).

Question 22. Where Should I Install My Access Point?

Answer :

The co-region of an get admission to point relies upon on the nature of the bodily region in which you want Wireless LAN coverage. It also relies upon at the sort of facility warehouse, office, convention room, domestic, and so on). The materials used in the bodily region have an crucial function. Cisco strongly recommends appearing a site survey before any get right of entry to factor is placed.

Question 23. Does Cisco Provide Any Management Software Or A Device To Manage Multiple Access Points (aps)?

Answer :

Yes. Cisco gives a control device recognise as Wireless LAN Solution Engine (ELSE) to manipulate a couple of APs. You can push configurations and upgrade firmware simultaneously for more than one APs. The radio surroundings in which the APs operate can be monitored and controlled by the WISE by periodically amassing RF information from the APs.

Question 24. What Is Dynamic Transmit Power Control (dtpc) And How Does It Work?

Answer :

DTPC is a beacon and probe statistics detail that lets in the get admission to factor to broadcast its transmit energy. Clients can use this statistics to robotically configure themselves to that electricity even as related to that get right of entry to point. In this manner, each devices transmit at the identical stage. The Cisco Wireless IP Phone 7920 mechanically adjusts its transmit electricity to the equal stage as the get entry to point to which it's far related.

BREW (Binary Runtime Environment for Wireless) Interview Questions
Question 25. What Is The Difference Between 802.3 Bridging And 802.Eleven Bridging?

Answer :

A bridge is a device that connects  or more networks. The bridges can be separated with the media kind they are connected with. If  wired networks are bridged together, then these are called 802.Three bridging at the same time as the ones which bridges the wi-fi network with the wired network are referred to as 802.11 bridges. 802.3 frames differs in layout and length that those of 802.11 frames. In order to talk among them, there ought to be a translation of body from one format to another. Translation is generally done via the access factor.

Question 26. If I Wish To Install Antenna At Some Distance From An Access Point (ap), Which Extension Cable Do I Need Between The Ap And The Antenna?

Answer :

There are  kinds of cable furnished by means of Cisco for mounting the antenna away from the radio unit LMR six hundred kind cable and LMR400 kind cables. These are low loss cables designed for higher efficiency.