Lesson 12 Flashcards
Ad hoc wireless network
Offers equal sharing between devices without the use of a wireless access point (WAP).
Basic service set (BSS)
A group of computers connected with a WAP and share the same SSID.
CSMA/CA
Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) is the transmission type used with wireless networks. CSMA/CA prevents collisions, whereas CSMA/CD contends with the collision after it happens.
CSMA/CD
Carrier Sense Multiple Access/Collision Detection (CSMA/CD) defines the rules for network communication on an Ethernet LAN. It detects collisions and dictates how data is resent after a collision.
Extended service set (ESS)
An ESS is an extension of a basic service set (BSS). It connects multiple BSSs together using more than one WAP as wireless repeaters.
IEEE 802.1a
A wireless standard that uses a frequency of 5 GHz and supports speeds as high as 54 Mbps.
IEEE 802.1b
A wireless standard that uses a frequency of 2.4 GHz and supports speeds as high as 11 Mbps.
IEEE 802.1g
A wireless standard that uses a frequency of 2.4 GHz and supports speeds as high as 54 Mbps.
IEEE 802.1n
A wireless standard that uses frequencies of 2.4 GHz and 5 GHz and supports speeds as high as 300 Mbps.
IEEE 802.1x
A group of technologies that increases security with a network. It ensures that clients are authenticated before granting access to a network. WPA2 Enterprise mode uses an 802.1x server for authentication.
Institute of Electrical and Electronics Engineers (IEEE)
A professional association that creates standards for networking. It created the IEEE 802.3 standard used for Ethernet and the IEEE 802.11 standard used for wireless.
Point-to-point (P2P) wireless
Technology used to bridge wired networks in two buildings with wireless methods. A P2P bridge is useful when a wired connection is not feasible or affordable.
Service set identifier (SSID)
The SSID is the logical name of the wireless network. All wireless devices must be in the same SSID to communicate.
War driving
The act of driving a car through an area and scanning for wireless networks. Attackers war drive to locate wireless networks and tap into wireless networks with weak security.
Wi-Fi Protected Access (WPA)
WPA was introduced as an interim replacement for WEP until WPA2 could be finalized. WPA offers significantly improved security over WEP without requiring additional hardware. WPA can be used in WPA Personal mode with a preshared key or WPA Enterprise mode with an 802.1x server.
Wi-Fi Protected Access version 2 (WPA2)
WPA2 provides a permanent fix for the security problems of WEP and is standardized as IEEE 802.11i. WPA2 requires different hardware than that used by WEP and uses the Advanced Encrypted Standard (AES) encryption method. WPA2 can be used in WPA Personal mode with a preshared key or WPA2 Enterprise mode with an 802.1x server.
Wired Equivalent Privacy (WEP)
WEP was the first encryption model offered for wireless network. It is insecure and should be used only in current wireless networks as a last resort.
Wireless Access Point (WAP)
A WAP is a device that is located between a wired LAN and a group of wireless clients. It bridges the wireless devices to the wired LAN.
Which of the following statements about the service set identifier (SSID) are true?
The SSID is an alphanumeric information field with a maximum value of 32 bits.
The SSID is a logical network name for a wireless network.
Which of the following is used by wireless devices to connect to a network?
Wireless access point
What frequency does an 802.11n network use?
5 GHz
2.4 MHz
Your company is planning to lease a second building, which is about 2 miles away. You’re asked how the networks between the two buildings can be connected. What would you suggest?
Connect the buildings with a P2P bridge.
Of the following security methods, which one is the most secure?
WPA2 Enterprise Mode
True or false. IEEE 802.11n networks can operate at speeds as high as 300 Mbps
True
Which of the following is a “listen before talk” method used to minimize collisions caused by simultaneous transmission by multiple radios?
CSMA/CA
Which of the following is a directional antenna consisting of a driven element and additional parasitic elements?
Yagi
What is the maximum speed of an IEEE 802.11b network?
11 Mbps
Wireless networks use a centralized device known as a ____, which transmits signals to devices with wireless NICs installed on them.
WAP
What frequency does an 802.11a network use?
5 GHz
Which of the following is used in wireless networks to identify a wireless access point and its associated network?
SSID
Which of the following frequency ranges does 802.11b use?
2.4 GHz
True or false. A WAP and a wireless router are the same thing.
False
True or false. 802.11 networks use CSMA/CD.
False
Which of the following is the maximum throughput of an 802.11n network?
600 Mbps
Which of the following are configured on a user workstation for wireless networking?
SSID (Service Set Identifier)
Encryption
Which of the following is the highest bit rate supported by 802.11g?
54 Mbps
Which of the following security encryption protection techniques is designed for home and small office networks and does not require an authentication server?
WPA-Personal
Which of the following is a WLAN security standard that supports AES encryption?
WPA
Which of the following WLAN standards operate at the frequency of 2.4GHz?
Each correct answer represents a complete solution
- 11b
802. 11g
Which of the following standards has a maximum data transmission speed of 600 Mbps?
802.11n
You work as a Network Administrator for Tech Perfect Inc. The company has a Windows-based network. You have to configure a wireless LAN on your network. Two separate buildings across from each other are to be connected wirelessly. Which of the following steps will you choose to accomplish the task?
Configure one Wireless Access Point (WAP) in each building.
Place one outdoor Yagi-Uda antenna in each building facing towards each other.
Which of the following is an Institute of the Electrical and Electronics Engineering (IEEE) specification that defines standards for Ethernet?
802.3
You work as a network administrator for McRoberts Inc. You’re configuring a wireless network for the company. You decide to use 802.11b WAPS (wireless access points) for the network. Which of the following could affect the network range?
A long length of antenna extension cable
The 2.4GHz interference
Match the networking standards to the method of transmitting data on various bands used by them.
IEEE 802.11g: Orthogonal frequency division multiplexing
IEEE 802.11b: Direct sequence spread spectrum
IEEE 802.11: Frequency hopping spread spectrum
IEEE 802.11a: Orthogonal frequency division multiplexing
Which of the following access methods is used by Ethernet standard networks?
CSMA/CD
You are configuring a wireless network for a home user. You do not want neighbors to detect the wireless network. What should you do?
Disable SSID broadcast.
Which of the following channel access methods is used in IEEE 802.11 networks?
CSMA/CA
Match the security methods with their security levels.
Wired Equivalent Privacy (WEP): Low, cracked in 2001 Wi-Fi Protected Access (WPA): Medium, cracked in 2008
Wi-Fi Protected Access 2: Strong
802.1x: Strongest (when used with WPA2)
Which of the following is the reason of using ad hoc networking in a wireless network?
To enable wireless computers to form a network when none of the wireless access points is present
Which of the following is used by 802.11 wireless communications?
CSMA/CA
Select the correct combinations of speed and frequency for the following wireless standards.
- 11a: 54Mbps & 5GHz
- 11b: 11Mbps & 2.4GHz
- 11g: 54Mbps & 2.4GHz
- 11n: 300Mbps & 2.4GHz
Which of the following is the function of an infrastructure mode WLAN?
To connect wireless clients to a wired network
“Entities in a network can both request and provide network services.”
Which of the following network models does this quote describe?
Peer-to-peer
Which of the following is the function of a RADIUS server in a wireless network that is secured by using WPA?
Providing a user authentication
Identifying wireless protocols
Wi-Fi: Began as the 802.11b IEEE standard and has an indoor transmission range of up to 35 meters.
WiMax: Point-to-multipoint broadband wireless access standard that is an emerging standard for long distances.
Bluetooth: A short-range wireless technology limited to transmission distances of about 100 meters, which confines it to connecting nodes within a single room or adjacent rooms.
802.11a: Improved version of the original Wi-Fi technology based on the same IEEE 802 standard. Has an indoor transmission range of up to 35 meters.
Identifying wireless acronyms
SSID: The network name needed to connect to a wireless AP.
ESSID: The network name used with an ESS wireless network design.
BSA: The APs coverage area, which depends on the AP antenna and any interference in the area.
ESS: Two or more connected BSSs that use multiple APs.