Section4 – Prepare infrastructure to support advanced services
QUESTION NO: 81
What is the function of the Service Set Identifier (SSID) in the wireless LAN?
A. The SSID should be configured on the client site only and provides data-privacy functions and authentication to the access point.
B. The SSID must match on both the client and the access point. The SSID is advertised in plain-text in the access point beacon messages.
C. The SSID must match on both the client and the access point and provides encryption keys for authentication to the access point.
D. The SSID must match on both the client and the access point and provides MAC Address Authentication to authenticate the client to the access point.
Answer: B
Explanation:
The SSID is the name of the wireless cell. It is used to logically separate Wireless LANs. It must match exactly between the client and the access point. The SSID is advertised in plain-text in the access point beacon messages (Figure 8). Although beacon messages are transparent to users, an eavesdropper can easily determine the SSID with the use of an 802.11 wireless LAN packetanalyzer, like Sniffer Pro. Some access-point vendors, including Cisco, offer the option to disable SSID broadcasts in the beacon messages. The SSID can still be determined by sniffing the probe response frames from an access point. The SSID is not designed, nor intended for use, as a security mechanism. In addition, disabling SSID broadcasts might have adverse effects on Wi-Fi interoperability for mixed-client deployments. Therefore, Cisco does not recommend using the SSID as a mode of security.
QUESTION NO: 82
Which two statements correctly describe the association process between a lightweight access point and a WLAN controller?
A.In order to associate in Layer 3 mode, the access point must have been preconfigured with an IP address.
B.An access point first searches for a controller in LWAPP Layer 2 mode. If the search is not successful, the access point then attempts to locate a controller in LWAPP Layer 3 mode.
C.Once an access point associates with a controller in LWAPP Layer 3 mode, it receives an IP address from the controller.
D.An access point will search for a controller using a broadcast address if using LWAPP Layer 2 mode and a unicast address if using LWAPP Layer 3 mode.
E.If multiple wireless controllers are detected by an access point, the controller with the fewest associated access points is chosen to associate with.
Answer: B E
QUESTION NO: 83
Which three components are included in the Cisco autonomous WLAN solution? (Choose three.)
A.,Wireless LAN Solution Engine (WLSE)
B.Access Control Server (ACS)
C.Wireless Control System (WCS)
D.Wireless Services Module (WiSM)
E.Wireless Domain Services (WDS)
F.Lightweight Access Point Protocol (LWAPP)
Answer: A B E
Explanation:
CiscoWorks WLSE is a complete solution for managing Cisco Aironet autonomous WLAN networks. As the management component of the Cisco Autonomous WLAN Solution, CiscoWorks WLSE provides comprehensive air/radio frequency (RF) and device-management capabilities in ways that simplify deployment, reduce operational complexity, and provide administrators visibility into the WLAN.
CiscoWorks WLSE provides an easy-to-use deployment wizard to specify the configuration criteria up front. This allows administrators to automate deployment and simultaneously maintain control in rapidly expanding environments. The deployment wizard also simplifies and automates the setup of the Wireless Domain Services (WDS) that plays an important role in the Cisco Autonomous WLAN Solution for seamless mobility and RF aggregation services.
WLSE also enables centralized user administration by integrating with Cisco Secure ACS. Users can be defined and mapped to a user role centrally on Cisco Secure ACS.
QUESTION NO: 84
What three statements are true for networks that are enabled for voice as well as data traffic? (Choose three.)
A.An uptime of 99.999 percent is achieved using a 4-hour service response contract for system problems.
B.Auxiliary VLANs provide the ability to apply QoS to voice traffic without affecting the flow of data from the client PC.
C.Redundant hardware, redundant links, UPS, and proactive network management are data network standards that do not apply to voice networks.
D.The increased costs of voice enabled networks are offset by increased worker productivity.
E.For ease of implementation, most VoIP phones use in-line power to get power through the same cable on which data is sent.
F.High availability networks must be created to avoid network congestion and overcome a lack of redundancy and poor engineering.
Answer: B E F
Explanation:
When adding voice or video to an existing network, you should examine several things in advance to provide the high level of availability users expect in their phone system: What features are needed?- Power for IP phones, voice VLANs on the switches, network redundancy for high availability, security for voice calls, and Quality of Service (QoS) settings. Electrical power for the
IP phones- Use either inline power from Catalyst switch or power patch panel. Need uninterruptible power supply (UPS) with auto-restart, monitoring, and 4-hour response contract.
May need generator backup. Maintain correct operating temperatures.
Auxiliary (or Voice) VLANs Cisco switches can be configured to dynamically place IP telephones into a VLAN separate from the data VLANs. They can do this even when the phone and PC are physically connected to the same switch port. This is called an auxiliary VLAN or a voice VLAN. Voice VLANs allow phones to be dynamically placed in a separate IP subnet from hosts, to have QoS (using 802.1Q/p headers) and security policies applied, and makes troubleshooting easier.
