IT Essentials Ch. 6 Applied Networking

A newly-installed wireless network has slow data transfer and frequent loss of connectivity.

What might be the problem?

• Interference from outside sources.

• The DHCP server is faulty.

• The antenna on the access point is too powerful.

• The network passwords need to be reissued to the users.

Answer explanation

Normally, the closer a wireless NIC is to an access point, the faster the connectivity. This problem does not require the network password to be reissued. The combination of the low bandwidth and the intermittent connectivity is pointing towards a weak signal or interference from outside sources.

That same new wireless network has slow data transfer and frequent loss of connectivity.

What else might be the problem?

• The wireless signal is too weak.

• The DHCP server is faulty.

• The antenna on the access point is too powerful.

• The network passwords need to be reissued to the users.

Answer explanation

The combination of the low bandwidth and the intermittent connectivity is pointing towards a weak signal or interference from outside sources.

A wired network is undergoing several changes that could leave it vulnerable to connection by unauthorized devices while the work is in progress. What temporary measure would enable authorized devices to continue to have network access but prevent unauthorized?

• Disable DNS.

• Disable SSID broadcast.

• Disable DHCP.

• Subnet the network.

Answer explanation

Disabling DHCP and assigning static IP addresses only to authorized devices will prevent unauthorized devices from automatically obtaining IP address information. Without the correct IP address information, the unauthorized devices will not be able to communicate over the network. Disabling DNS will result in all connected devices no longer automatically being able to communicate with network resources by name (IP addresses would have to be used.), but will not prevent unauthorized devices from connecting and enabling potentially malicious access from occurring. Subnetting the network will change the range of IP addresses used but not prevent unauthorized network access. Disabling SSID broadcasts is only applicable to wireless networks, not wired networks.

The same wired network is undergoing several changes that could leave it vulnerable to connection by unauthorized devices while the work is in progress. What other temporary measure would enable authorized devices to continue to have network access but prevent unauthorized?

• Disable DNS.

• Disable SSID broadcast.

• Assign static IP addresses to the authorized devices.

• Subnet the network.

Answer explanation

Disabling DHCP and assigning static IP addresses only to authorized devices will prevent unauthorized devices from automatically obtaining IP address information. Without the correct IP address information, the unauthorized devices will not be able to communicate over the network. Disabling DNS will result in all connected devices no longer automatically being able to communicate with network resources by name (IP addresses would have to be used.), but will not prevent unauthorized devices from connecting and enabling potentially malicious access from occurring. Subnetting the network will change the range of IP addresses used but not prevent unauthorized network access. Disabling SSID broadcasts is only applicable to wireless networks, not wired networks.

What default wireless router setting can affect network security?

• The SSID is broadcast.

• MAC address filtering is enabled.

• WEP encryption is enabled.

• The wireless channel is automatically selected.

Answer explanation

Default settings on wireless routers often include broadcasting the SSID and using a well-known administrative password. Both of these pose a security risk to wireless networks. WEP encryption and MAC address filtering are not set by default. The automatic selection of the wireless channel poses no security risks.

What is another default wireless router setting that can affect network security?

• A well-known administrator password is set.

• MAC address filtering is enabled.

• WEP encryption is enabled.

• The wireless channel is automatically selected.

Answer explanation

Default settings on wireless routers often include broadcasting the SSID and using a well-known administrative password. Both of these pose a security risk to wireless networks. WEP encryption and MAC address filtering are not set by default. The automatic selection of the wireless channel poses no security risks.

A technician issues the ipconfig /all command. to see if the DHCP client is working correctly. Which is a parameter the technician should review?

• description

• default gateway

• host name

• media state

Answer explanation

A DHCP server can provide several parameters such as IP address, subnet mask, default gateway, and other optional parameters.

The host name, media state, and description are present even if a DHCP server is not found.

A technician issues the ipconfig /all command. to see if the DHCP client is working correctly. Which is another parameter the technician should review?

• description

• subnet mask

• host name

• media state

Answer explanation

A DHCP server can provide several parameters such as IP address, subnet mask, default gateway, and other optional parameters.

The host name, media state, and description are present even if a DHCP server is not found.

A computer has 169.254.100.88 assigned as an IP address. What is the most likely problem?

• The IP default gateway on the computer is incorrect.

• The network interface card driver needs to be updated.

• The router that connects this network to other networks is down.

• The computer cannot communicate with a DHCP server.

Answer explanation

In a network employing dynamic IP addressing, if a computer cannot communicate with the DHCP server to obtain an IP address, the Windows operating system automatically assigns a link-local IP, which is in the range of 169.254.0.0 to 169.254.255.255. In this case, the computer can only communicate with computers connected to the same network within this IP address range.

A user can print to a printer that is on the same network, but the traffic of the user cannot reach the Internet. What is a possible cause of the problem?

• The NIC on the PC is faulty.

• The network cable connected to the user PC is faulty.

• The PC has an incorrect IP address.

• The PC default gateway address is missing or incorrect.

Answer explanation

The default gateway IP address is used to reach other networks, including the Internet.