CCNA FOR YOU

Wireless LAN Standards

2011-08-03T00:33:00.000-07:00

At the time this book was published, the IEEE had ratiﬁed four major WLAN standards:

802.11, 802.11a, 802.11b, and 802.11g. This section lists the basic details of each WLAN standard, along with information about a couple of other standards bodies. This section also brieﬂy mentions the emerging 802.1n standard, which the IEEE had not yet ratiﬁed by the time this Post was published.

Of the organizations listed in this table, the IEEE develops the speciﬁc standards for the different types of WLANs used today. Those standards must take into account the frequency choices made by the different worldwide regulatory agencies, such as the FCC in the U.S. and the ITU-R, which is ultimately controlled by the United Nations (UN).

The IEEE introduced WLAN standards with the creation of the 1997 ratiﬁcation of the 802.11 standard. This original standard did not have a sufﬁx letter, whereas later WLAN standards do. This naming logic, with no sufﬁx letter in the ﬁrst standard, followed by other standards with a sufﬁx letter, is like the original IEEE Ethernet standard. That standard was 802.3, with later, more-advanced standards having a sufﬁx, such as 802.3u for Fast Ethernet.

WAN Comparisons with Ethernet LANs

2011-08-03T00:31:00.000-07:00

WLANs are similar to Ethernet LANs in many ways, the most important being that WLANs allow communications to occur between devices. The IEEE deﬁnes standards for both, using the IEEE 802.3 family for Ethernet LANs and the 802.11 family for WLANs.
Both standards deﬁne a frame format with a header and trailer, with the header including a source and destination MAC address ﬁeld, each 6 bytes in length. Both deﬁne rules about how the devices should determine when they should send frames and when they should not.

The biggest difference between the two lies in the fact that WLANs use radiated energy waves, generally called radio waves, to transmit data, whereas Ethernet uses electrical signals ﬂowing over a cable (or light on optical cabling). Radio waves pass through space, so technically there is no need for any physical transmission medium. In fact, the presence of matter—in particular, walls, metal objects, and other obstructions—gets in the way of the wireless radio signals.

Wireless LAN Concepts

2011-08-03T00:30:00.000-07:00

Many people use WLANs on a regular basis today. PC sales continue to trend toward more laptop sales versus desktop computers, in part to support a more mobile workforce. PC users need to connect to whatever network they are near, whether at work, at home, in a hotel, or at a coffee shop or bookstore. The migration toward a work model in which you ﬁnd working moments wherever you are, with a need to be connected to the Internet at any time, continues to push the growth of wireless LANs.

The wireless-capable customer laptops communicate with a WLAN device called an access point (AP). The AP uses wireless communications to send and receive frames with the WLAN clients (the laptops). The AP also connects to the same Ethernet LAN as the bookstore’s own devices, allowing both customers and employees to communicate with other sites.
This section begins the chapter by explaining the basics of WLANs, starting with a comparison of similarities between Ethernet LANs and WLANs. The rest of the section then explores some of the main differences.

What value is primarily used to determine which port becomes the root port on each non root switch in a spanning-tree topology?

2011-07-17T20:33:00.002-07:00

What value is primarily used to determine which port becomes the root port on each non root switch in a spanning-tree topology?

A. path cost
B. lowest port MAC address
C. VTP revision number
D. highest port priority number
E. port priority number and MAC address

Answer: E

What is the function of the CSMA/CD algorithm in Ethernet technologies?

2011-07-17T20:33:00.001-07:00

A. defines how the media is accessed
B. supplies a token to determine which host has access to the media
C. defines the encoding of electrical signals on the wire
D. determines the preamble bits

Answer: A

Study the Exhibit carefully. Switch1 sends a VTP advertisement and Switch2 receives it. Which statement accurately describes how Switch2 will respond?

2011-07-17T20:24:00.000-07:00

Study the Exhibit carefully. Switch1 sends a VTP advertisement and Switch2 receives it. Which statement accurately describes how Switch2 will respond?

A. Switch2 will add 2 VLANs to its VLAN database and change the configuration revision number to 232
B. Switch2 will remove 2 VLANs from its VLAN database and change the configuration revision number to 232
C. Switch2 will enable VTP pruning, add two VLANs, and increment the configuration revision number to 233
D. Switch2 will ignore the VTP advertisement

Which of the following should be placed between a heatsink and a processor setting them in place?

2011-06-14T07:15:00.001-07:00

A: Thermal grease.
B: Rubber cement.
C: Plastic plate.
D: Ceramic plate.
Answer: A

What is the benefit of an Energy Star compliant computer? (Choose two)

2011-06-14T07:14:00.000-07:00

A. Will last longer before breaking down.
B. Is manufactured with less toxic chemicals.
C. Runs cooler.
D. Uses less electricity.

Answer: C, D

A customer complains that a recently upgraded computer shuts down after a few minutes of operation. You verify the power supply is working correctly.

2011-06-14T07:13:00.000-07:00

A customer complains that a recently upgraded computer shuts down after a few
minutes of operation. You verify the power supply is working correctly.
Which of the following is the NEXT component you should check?

A. CPU cooling fan
B. Computer memory
C. IDE Harddrives
D. CMOS battery

Answer: A

A customer has a cable that has a connector with 15 pins. The pins are arranged in three rows of 5 pins. What would this cable be used for?

2011-06-14T07:12:00.000-07:00

A customer has a cable that has a connector with 15 pins. The pins are arranged in three rows of 5 pins. What would this cable be used for?

A. Game Port
B. COM Port
C. VGA Monitor
D. LPT Port

Answer: C

What is IEEE 1394b also known as?

2011-06-14T07:11:00.001-07:00

What is IEEE 1394b also known as?

A. Firewire 400
B. USB 1.0
C. Firewire 800
D. USB 2.0
Answer: C

Which Printer interface Operates at either 400 or 800 Mbps?

2011-06-14T07:10:00.003-07:00

Which Printer interface Operates at either 400 or 800 Mbps?

A. Ethernet
B. FireWire
C. Parallel
D. Serial
Answer: B

Upgrading to a new AGP video card from a PCI video card has which of the following benefits?

2011-06-14T07:10:00.001-07:00

A. Reduces heat inside the system unit
B. Frees up a USB slot
C. AGP type video cards have a newer design over the PC vide cards
D. Increases the video performance
Answer: D

Identify the I/O port described below. An external D Shaped connectors with a total of 15 female pins in 3 rows.

2011-06-14T07:09:00.001-07:00

Identify the I/O port described below. An external D Shaped connectors with a total of 15 female pins in 3 rows.

A. Parellel Port.
B. Serial Port.
C. VGA Video Port
D. Joy Stick/MIDI Port.
E. USB Port.
Answer: C

When installing a new video card in a system which previously used an onboard video controller, the onboard video controller needs to be

2011-06-14T07:07:00.001-07:00

When installing a new video card in a system which previously used an onboard
video controller, the on-board video controller needs to be

A. disabled in the windows control panel
B. disable in the BIOS
C. Physically removed.
D. disable using the jumper pin on the new video card.
Answer: B

Which of the following will allow you to use a laptop as a desktop system? (Select two)

2011-06-14T07:00:00.000-07:00

Which of the following will allow you to use a laptop as a desktop system? (Select
two)
A. External Hard drive
B. Port Replicator
C. Hot Swappable drive
D. Docking station
E. Home base
Answer: B, D

A client wants to upgrade the storage in a computer. The original drive is working, just the owner needs additional free space. The technician install

2011-06-10T08:55:00.002-07:00

A client wants to upgrade the storage in a computer. The original drive is working,

just the owner needs additional free space. The technician installs a new 40GB ATA Hard drive in the system. It can be heard spinning up, but the drive is NOT recognized by the system's BIOS. Select the MOST likely problems. (Select Two)

A. Faulty Harddrive
B. Incompatible Operating System
C. Drive capacity too large for BIOS
D. Incorrect termination

Answer: A, C

When installing an ISA Modem it would be good practice to know available and_______to use before installing the modem.(Select Two).

2011-06-10T08:55:00.001-07:00

A. SCSI/IDs
B. COM Ports
C. ISA address
D. IRQ number.
Answer: B, D

A customer just installed a new CD-RW. The system was working fine before the installation, but now the CD-RW does not work.

2011-06-10T08:54:00.001-07:00

A customer just installed a new CD-RW. The system was working fine before the installation, but now the CD-RW does not work. What should you suggest that the customer should do?

A. Flash or upgrade the BIOS

B. Check the CONFIG.SYS setup

C. Add the CD-RW in the device manager

D. Check the jumper settings on the CD-RW

Answer: D

A workstation has just been installed on the Ethernet LAN but cannot communicate with the network. What should you do first?

2011-06-10T08:53:00.004-07:00

A. Reinstall the network protocols.

B. Reinstall the network interface card driver.

C. Verify the IP configuration on the workstation.

D. Verify the link status on the computer’s network card.

Answer: D

Which device would you plug into an AGP slot?

2011-06-10T08:53:00.003-07:00

A. Hard drive

B. Serial port

C. Video card

D. External storage device

Answer: C

A video resolution of 800 into 600 would constitute which video mode?

2011-06-10T08:53:00.001-07:00

A. EGA

B. VGA

C. CGA

D. SVGA

Answer: D

Which ports are most often used to connect a digital camera to a computer? (Choose two)

2011-06-10T08:52:00.004-07:00

A. USB Port

B. SCSI Port

C. PS/2 Port

D. Parallel Port

E. RS-232 Port

Answer: A, E

A bent pin on a three row DB-15 male connector plug could cause problems with which device or component?

2011-06-10T08:52:00.003-07:00

A. Monitor

B. Joy sticks

C. Laser-Jet Printer

D. External Modem

Answer: A

Which of the following source present a risk factor for virus infection on a PC? (Choose two)

2011-06-10T08:52:00.001-07:00

A. A floppy disk received from a friend.

B. A downloaded file from the internet.

C. FDISK/MBR file on the hard drive.

D. . DLL file that was loaded with a new machine.

E. .CAB file that was loaded with the new machine.

Answer: A, B

What is the main difference between AT and ATX motherboards? (Choose two)

2011-06-10T08:51:00.003-07:00

A. PS/2 port

B. BNC connector

C. Soft power switch

D. Serial connectors

E. Parallel connectors

Which of the following configuration settings are set in EEPROMS on a NIC? (Choose three)

2011-06-10T08:51:00.001-07:00

A. IRQ

B. Protocol

C. IP Address

D. I/O Address

E. MAC address

Answer: A, D, E

How many devices does USB support?

2011-06-10T08:50:00.001-07:00

A. 32

B. 64

C. 127

D. 256

Answer: C

The computer will not boot from the floppy drive. What are the most likely causes?

2011-06-10T08:49:00.000-07:00

The computer will not boot from the floppy drive. What are the most likely causes?

(Choose two)

A. The floppy drive is defective.

B. There is no partition on the hard drive.

C. The boot floppy is formatted on FAT 16.

D. The boot sequence in the BIOS is incorrect

E. The hard drive has more than one partitions defined.

Answer: A, D

What are benefits of cleaning the inside of the computer? (Choose Two)

2011-06-10T08:48:00.002-07:00

A. Increase connectivity speed.

B. Provide better system cooling

C. Increase CPU processing speed.

D. Increase the value of your computer.

E. Reduce the risk of component failure.

Answer: B, E

You have just installed a new internal PCI modem in your desktop. It will not dial out. What is the problem?

2011-06-10T08:48:00.001-07:00

A. The port speed is set too high.

B. The modem has not been set up in control panel properties

C. The phone line is plugged in to the line-in port on the modem card.

D. The phone line out of the wall is plugged into the phone port on the modem

card.

Answer: D

How much video RAM is needed to display 1024 into 768 at 24bit color?

2011-06-10T08:47:00.003-07:00

A. 1MB.

B. 4MB.

C. 8MB.

D. 512KB.

Answer: B

WRAM is used on a?

2011-06-10T08:47:00.001-07:00

A. Modem.

B. Video card.

C. Motherboard.

D. ATA controller.

Answer: B

What is a type of IDE translation?

2011-06-10T08:46:00.004-07:00

A. LBA

B. UTB

C. QIC

D. USB

Answer: A

With respect to the interface network card, what does the term 10/100 refer to?

2011-06-10T08:46:00.003-07:00

A. Protocol speed.

B. A fiber network.

C. Megabits per second.

D. Minimum and maximum server speed.

Answer: C

On the dot-matrix you only see the bottom half of the characters. What is a possible cause of this?

2011-06-10T08:46:00.001-07:00

A. Defective print head.

B. Wrong paper thickness.

C. Paper text incorrectly on tractor.

D. Defective home position sensor.

Answer: A

Which motherboard type allows you to turn off the computer via software?

2011-06-10T08:45:00.003-07:00

A. AT

B. ATX

C. MCA

D. VESA

Answer: B

Which memory address range is reserved for VGA video card?

2011-06-10T08:45:00.001-07:00

A. C000-C3FF

B. C000-C7FF

C. D000-D7FF

D. D000-DFFF

Answer: B

How should you open the tray on an inoperative Or Locked CD-ROM drive?

2011-06-10T08:44:00.002-07:00

A. Push the eject button.

B. Push in on the lower-right corner door.

C. Right-click the CD icon and select Eject.

D. Insert a paper clip into the CD drive eject hole.

Answer: D

What media would you use to send 800 MB to 2 GB files?

2011-06-10T08:44:00.001-07:00

A. Diskette

B. CD-ROM

C. DVD-ROM

D. External Hard drive

Answer: C

CCNA FOR YOU

Wireless LAN Standards

WAN Comparisons with Ethernet LANs

Wireless LAN Concepts

What value is primarily used to determine which port becomes the root port on each non root switch in a spanning-tree topology?

What is the function of the CSMA/CD algorithm in Ethernet technologies?

Study the Exhibit carefully. Switch1 sends a VTP advertisement and Switch2 receives it. Which statement accurately describes how Switch2 will respond?

Which of the following should be placed between a heatsink and a processor setting them in place?

What is the benefit of an Energy Star compliant computer? (Choose two)

A customer complains that a recently upgraded computer shuts down after a few minutes of operation. You verify the power supply is working correctly.

A customer has a cable that has a connector with 15 pins. The pins are arranged in three rows of 5 pins. What would this cable be used for?

What is IEEE 1394b also known as?

Which Printer interface Operates at either 400 or 800 Mbps?

Upgrading to a new AGP video card from a PCI video card has which of the following benefits?

Identify the I/O port described below. An external D Shaped connectors with a total of 15 female pins in 3 rows.

When installing a new video card in a system which previously used an onboard video controller, the onboard video controller needs to be

Which of the following will allow you to use a laptop as a desktop system? (Select two)

A client wants to upgrade the storage in a computer. The original drive is working, just the owner needs additional free space. The technician install

When installing an ISA Modem it would be good practice to know available ____ and___________to use before installing the modem.(Select Two).

A customer just installed a new CD-RW. The system was working fine before the installation, but now the CD-RW does not work.

A workstation has just been installed on the Ethernet LAN but cannot communicate with the network. What should you do first?

Which device would you plug into an AGP slot?

A video resolution of 800 into 600 would constitute which video mode?

Which ports are most often used to connect a digital camera to a computer? (Choose two)

A bent pin on a three row DB-15 male connector plug could cause problems with which device or component?

Which of the following source present a risk factor for virus infection on a PC? (Choose two)

What is the main difference between AT and ATX motherboards? (Choose two)

Which of the following configuration settings are set in EEPROMS on a NIC? (Choose three)

How many devices does USB support?

The computer will not boot from the floppy drive. What are the most likely causes?

What are benefits of cleaning the inside of the computer? (Choose Two)

You have just installed a new internal PCI modem in your desktop. It will not dial out. What is the problem?

How much video RAM is needed to display 1024 into 768 at 24bit color?

WRAM is used on a?

What is a type of IDE translation?

With respect to the interface network card, what does the term 10/100 refer to?

On the dot-matrix you only see the bottom half of the characters. What is a possible cause of this?

Which motherboard type allows you to turn off the computer via software?

Which memory address range is reserved for VGA video card?

How should you open the tray on an inoperative Or Locked CD-ROM drive?

What media would you use to send 800 MB to 2 GB files?

When installing an ISA Modem it would be good practice to know available and_______to use before installing the modem.(Select Two).