Chapter 8 Flashcards
Which of the following wireless IEEE standards operate on the 2.4 GHz radio frequency and are directly compatible with each other? (Choose two.)
- 11a
- 11b
- 11ac
- 11g
B, D. Both 802.11b and 802.11g operate in the 2.4 GHz range and use similar transmission standards. Many devices on the market are listed as 802.11b/g, meaning they will work with either system. Alternatively, 802.11a and 802.11ac operate in the 5 GHz range.
What is the primary function of the SSID?
To secure communication between a web server and a browser
To secure communication between a server and a remote host
To serve as a parameter used to identify a network and configure a wireless connection
To serve as a type of password used to secure a wireless connection
C. A service-set identifier (SSID) is the unique name given to the wireless network. All hardware that is to participate on the network must be configured to use the same SSID. Essentially, it is the network name. When you are using Windows to connect to a wireless network, all available wireless networks will be listed by their SSID.
Which of the following are features that allow 802.11ac to achieve higher data throughput? (Choose two.)
MIMO
Beamforming
Channel bonding
Code division multiplexing
A, C. The two technologies that 802.11ac employs to achieve high throughput are channel bonding and MIMO. Channel bonding is the combination of multiple smaller channels into one large channel for greater bandwidth. MIMO is enhanced over 802.11n to allow for more multiple inputs and outputs. 802.11ac also uses beamforming, but that helps the range, not the throughput.
What is the most secure wireless encryption standard for 802.11 networks?
WEP
WPA
WPA2
SAFER+
C. WEP was the original encryption standard developed for Wi-Fi networks, but it is easily hacked. WPA is an upgrade, but WPA2 is more secure and incorporates the entire 802.11i standard. SAFER+ is used to encrypt Bluetooth communications.
What level of QoS is designated for interactive voice and video?
1
4
5
6
C. QoS level 5 is designated for interactive voice and video, with less than 100ms delay. Level 1 is for background applications and is low priority. Level 4 is known as controlled load, which is lower priority than interactive voice and video. Level 6 only has 10ms latency but is reserved for control traffic.
You have just installed a wireless router on your home network. Which of the following should you do to make it highly secure? (Choose all that apply.)
Change the default administrator name and password.
Change the SSID.
Enable WEP.
Configure it to channel 11.
A, B. You should always change the default administrator name and password as well as the default SSID when installing a new wireless router. Enabling encryption is also a good idea, but WPA and WPA2 are better options than WEP. The channel has nothing to do with security.
You are setting up a small office network for a client. Which Internet service would you recommend to provide the best speed?
DSL Dial-up Satellite BRI ISDN PRI ISDN
A. Of the options listed, DSL provides the fastest speed. DSL can easily provide 12 Mbps downloads. Dial-up is limited to 56 Kbps, and BRI ISDN (128 Kbps) and PRI (about 1.5 Mbps) don’t even come close. Satellite is also much slower than DSL.
Which service allows users with private IP addresses to access the Internet using a public IP address?
DHCP
DNS
DMZ
NAT
D. Network Address Translation (NAT) allows users to have a private IP address and still access the Internet with a public IP address. NAT is installed on a router and translates the private IP address into a public address for the user to access the Internet. DHCP assigns IP configuration information to clients. DNS resolves hostnames to IP addresses. A DMZ is an area on a network between an external router and an internal router.
You are installing a single 802.11g wireless network. The office space is large enough that you need three WAPs. What channels should you configure the WAPs on to avoid communication issues?
2, 5, and 7
1, 8, and 14
1, 6, and 11
3, 6, and 9
C. There are 14 communication channels in the 2.4 GHz range, but only the first 11 are configurable. The three non-overlapping channels are 1, 6, and 11.
You are setting up a wireless network. Which wireless standards would give the users over 40 Mbps throughput? (Choose all that apply.)
- 11ac
- 11b
- 11g
- 11n
A, C, D. Three standards listed—802.11ac (1,300 Mbps), 802.11g (54 Mbps), and 802.11n (600 Mbps)—give users the required throughput.
You have been asked to configure a network for a small office. The wireless router is installed, and now you need to connect the client computers. What do you enter on the client computers to connect to the router?
The administrator password
The security passphrase
The client’s MAC address
The default router password
B. To join the network, client computers need to find the SSID, ensure that the security settings are correct (to match the router), and enter the security passphrase. As an administrator, you should have configured this passphrase to be different from the router’s administrator password.
Which of the following technologies can operate in the 125 kHz to 134 kHz range?
Bluetooth
RFID
NFC
LTE
B. Radio frequency identification (RFID) can operate in three frequency bands: 125 kHz to 134 kHz, 13.56 MHz, or 856 MHz to 960 MHz. Bluetooth is 2.4 GHz; NFC is 13.56 MHz; and LTE is between 600 MHz and 6 GHz.
Which of the following are advantages to using dial-up Internet service? (Choose two.)
High speed
Broad availability
Low cost
High security
B, C. Dial-up Internet is archaic by today’s standards, but it is widely available (anywhere there is phone service), and it’s generally lower in cost than other Internet access methods. It’s definitely not high speed, and its security is really no different from that of broadband Internet access methods.
Which of the following security standards was the first to introduce a dynamic 128-bit per-packet security key?
WEP
TKIP
AES
CCMP
B. WEP could use a 64-bit or 128-bit security key, but it was a static key. TKIP introduced a dynamic per-packet key. AES and CCMP came after TKIP.
You are running an 802.11g wireless router in mixed mode. You have three 802.11g wireless NICs using the router. A new user connects using an 802.11b wireless NIC. What will happen?
The user with 802.11b will access the network at 11 Mbps, while the users with 802.11g will access the network at 54 Mbps.
The user with 802.11b will not be able to communicate on the network.
The user with 802.11b will access the network at 11 Mbps. The users with 802.11g will access the network at 54 Mbps, unless they are communicating with the 802.11b device, which will be at 11 Mbps.
All users will access the network at 11 Mbps.
D. The good news is that 802.11g is backward compatible with 802.11b. The bad news is, if you run in a mixed environment, all devices that communicate with the WAP (or router) will be forced to slow down to accommodate the older technology.
