Module 13 - WLAN Configuration

A technician is about to install and configure a wireless network at a small branch office. What is the first security measure the technician should apply immediately upon powering up the wireless router?

• Configure encryption on the wireless router and the connected wireless devices.

• Disable the wireless network SSID broadcast.

• Change the default user-name and password of the wireless router.

• Enable MAC address filtering on the wireless router.

Answer explanation

The first action a technician should do to secure a new wireless network is to change the default user-name and password of the wireless router. The next action would usually be to configure encryption. Then once the initial group of wireless hosts have connected to the network, MAC address filtering would be enabled and SSID broadcast disabled. This will prevent new unauthorized hosts from finding and connecting to the wireless network.

Which service can be used on a wireless router to prioritize network traffic among different types of applications so that voice and video data are prioritized over email and web data?

• NAT

• QoS

• DNS

• DHCP

Answer explanation

Many wireless routers have an option for configuring quality of service (QoS). By configuring QoS, certain time-sensitive traffic types, such as voice and video, are prioritized over traffic that is not as time-sensitive, such as email and web browsing.

A network administrator is working to improve WLAN performance on a dual-band wireless router. What is a simple way to achieve a split-the-traffic result?

• Require all wireless devices to use the 802.11n standard.

• Check and keep the firmware of the wireless router updated.

• Make sure that different SSIDs are used for the 2.4 GHz and 5 GHz bands.

• Add a Wi-Fi range extender to the WLAN and set the AP and the range extender to serve different bands.

Answer explanation

By default, dual-band routers and APs use the same network name on both the 2.4 GHz band and the 5 GHz band. The simplest way to segment traffic is to rename one of the wireless networks.

A technician is troubleshooting a slow WLAN that consists of 802.11b and 802.11g devices . A new 802.11n/ac dual-band router has been deployed on the network to replace the old 802.11g router. What can the technician do to address the slow wireless speed?

• Change the SSID.

• Configure devices to use a different channel.

• Split the wireless traffic between the 802.11n 2.4 GHz band and the 5 GHz band.

• Update the firmware on the new router.

Answer explanation

Splitting the wireless traffic between the 802.11n 2.4 GHz band and the 5 GHz band will allow for the 802.11n to use the two bands as two separate wireless networks to help manage the traffic, thus improving wireless performance.

A network administrator of a college is configuring the WLAN user authentication process. Wireless users are required to enter username and password credentials that will be verified by a server. Which server would provide such service?

• AAA

• NAT

• SNMP

• RADIUS

Answer explanation

Remote Authentication Dial-In User Service (RADIUS) is a protocol and server software that provides user-based authentication for an organization. When a WLAN is configured to use a RADIUS server, users will enter username and password credentials that are verified by the RADIUS server before allowing to the WLAN.

Which three parameters would need to be changed if best practices are being implemented for a home wireless AP? (Choose three.)

• SSID

• AP password

• antenna frequency

• wireless beacon time

• wireless network password

A laptop cannot connect to a wireless access point. Which two troubleshooting steps should be taken first? (Choose two.)

• Ensure that the wireless NIC is enabled.

• Ensure that the laptop antenna is attached.

• Ensure that the wireless SSID is chosen.

• Ensure that the correct network media is selected.

• Ensure that the NIC is configured for the proper frequency.

Answer explanation

A wireless laptop normally does not have an antenna attached unless a repair has recently been implemented. If the wireless NIC is enabled, the correct media, radio, will be used. When the NIC detects an access point, the correct frequency is automatically used.

A network administrator is configuring a RADIUS server connection on a Cisco 3500 series WLC. The configuration requires a shared secret password. What is the purpose for the shared secret password?

• It allows users to authenticate and access the WLAN.

• It is used by the RADIUS server to authenticate WLAN users.

• It is used to authenticate and encrypt user data on the WLAN.

• It is used to encrypt the messages between the WLC and the RADIUS server.

Answer explanation

The RADIUS protocol uses security features to protect communications between the RADIUS server and clients. A shared secret is the password used between the WLC and the RADIUS server. It is not for end users.

A network engineer is troubleshooting a newly deployed wireless network that is using the latest 802.11 standards. When users access high bandwidth services such as streaming video, the wireless network performance is poor. To improve performance the network engineer decides to configure a 5 Ghz frequency band SSID and train users to use that SSID for streaming media services. Why might this solution improve the wireless network performance for that type of service?

• The 5 GHz band has a greater range and is therefore likely to be interference-free.

• Requiring the users to switch to the 5 GHz band for streaming media is inconvenient and will result in fewer users accessing these services.

• The 5 GHz band has more channels and is less crowded than the 2.4 GHz band, which makes it more suited to streaming multimedia.

• The only users that can switch to the 5 GHz band will be those with the latest wireless NICs, which will reduce usage.

Answer explanation

Wireless range is determined by the access point antenna and output power, not the frequency band that is used. In this scenario it is stated that all users have wireless NICs that comply with the latest standard, and so all can access the 5 GHz band. Although some users may find it inconvenient to switch to the 5 Ghz band to access streaming services, it is the greater number of channels, not just fewer users, that will improve network performance.

Which step is required before creating a new WLAN on a Cisco 3500 series WLC?

• Create a new SSID.

• Create a new VLAN interface.

• Build or have an SNMP server available.

• Build or have a RADIUS server available.

Answer explanation

Each new WLAN configured on a Cisco 3500 series WLC needs its own VLAN interface. Thus it is required that a new VLAN interface to be created first before a new WLAN can be created.