Home » SWITCH 642-813 Q&As » Section 4 - Prepare Infrastructure » 642-813 Q&A – Prepare infrastructure to support advanced services (36-40)

642-813 Q&A – Prepare infrastructure to support advanced services (36-40)

Section4 – Prepare infrastructure to support advanced services

QUESTION NO: 36
Refer to the exhibit. Which statement is true about the voice traffic coming to the switch access port that is connected to the IP phone?

37

A. The voice VLAN must be configured as a native VLAN on the switch.
B. The traffic on the voice VLAN must be tagged with 802.1p encapsulation in order to coexist on the same LAN segment with a PC.
C. A PC connected to a switch port via an IP phone must support a trunking encapsulation.
D. A PC connected to a switch port via an IP phone is unaware of the presence of the phone.
E. To improve the quality of the voice traffic, no other devices should be attached to the IP phone.
Answer: D
Explanation:
The new voice VLAN is called an auxiliary VLAN in the Catalyst software command-line interface (CLI). In the traditional switched world, data devices reside in a data VLAN. The new auxiliary VLAN is used to represent other types of devices collectively. Today those devices are IP phones (hence the notion of a voice VLAN), but, in the future, other types of non-data devices will also be part of the auxiliary VLAN. Just as data devices come up and reside in the native VLAN (default VLAN), IP phones come up and reside in the auxiliary VLAN, if one has been configured on the switch.
When the IP phone powers up, it communicates with the switch using CDP. The switch then provides the phone with its configured VLAN ID (voice subnet), also known as the voice VLAN ID or VVID. Meanwhile, data devices continue to reside in the native VLAN (or default VLAN) of the switch. A data device VLAN (data subnet) is referred to as a port VLAN ID or PVID.

QUESTION NO: 37
Refer to the exhibit. What statement is true about the configuration on switch CAT1?

36
A. The configuration establishes policed DSCP on ports Fa0/11 and Fa0/12 with values ranging from 8 to 56.
B. The configuration overrides 802.1p priorities on packets entering ports Fa0/11 and Fa0/12 with a value of 48.
C. Untagged Port VLAN ID (PVID) frames will carry voice traffic on VLAN 40.
D. Two IP phones with the MAC addresses of 0008.8595.d1a7 and 0007.8595.d2b7 are connected to CAT1 ports Fa0/11 and Fa0/12, respectively.
E. Security violation shutdown mode has been activated for ports Fa0/11 and Fa0/12.
F. The configuration overrides the Quality of Service value in packets entering ports Fa0/11 and Fa0/12 with a value of 45.
Answer: D
Explanation:
Port security is a feature supported on Cisco Catalyst switches that restricts a switch port to a specific set or number of MAC addresses. Those addresses can be learned dynamically or configured statically. The port will then provide access to frames from only those addresses. If, however, the number of addresses is limited to four but no specific MAC addresses are configured, the port will allow any four MAC addresses to be learned dynamically, and port access will be limited to those four dynamically learned addresses.

QUESTION NO: 38
Refer to the exhibit. Which two Lightweight Access Point statements are true? (Choose two.)

38
A. Real time events such as authentication, security management, and mobility are handled by the lightweight AP.
B. WLAN controllers provide a single point of management.
C. An AP that has been upgraded from an autonomous AP to lightweight AP will only function in conjunction with a Cisco Wireless controller.
D. Lightweight APs require local configuration using local management.
E. Autonomous APs receive control and configuration information from a WLAN controller.
F. LWAPP increases the amount of processing within the APs, enabling them to support filtering and policy enforcement features.
Answer: BC
Explanation:
In the Cisco Centralized Wireless LAN Architecture, access points operate in lightweight mode.
The access points associate to a Cisco wireless LAN controller. The controller manages the configuration, firmware, and control transactions such as 802.1x authentications. In addition, all wireless data traffic is tunneled through the controller.
The Lightweight Access Point Protocol (LWAPP) is an IETF draft protocol that defines the control messaging for setup and path authentication and run-time operations. LWAPP also defines the tunneling mechanism for data traffic.
A lightweight access point discovers a controller using LWAPP discovery mechanisms and then sends it an LWAPP join request. The controller sends the access point an LWAPP join response allowing the access point to join the controller. When the access point is joined to the controller, it downloads its software if the revisions on the access point and controller do not match.
Subsequently, the access point is completely under the control of the controller.
No lightweight access point can operate independently from a WLC, including those upgraded from an autonomous AP. Each lightweight access point must discover a WLC, issue an LWAPP join request, and if successful, receive a join response to become joined to a controller.

QUESTION NO: 39
Refer to the exhibit. Which protocol establishes an optimal path to the root in a wireless mesh network?

39
A.WLAN Quality of Service (WQoS)
B.802.1Q WLAN trunking protocol
C.Lightweight Access Point Protocol (LWAPP)
D.Layer 2 Roaming (IAPP)
E.Adaptive Wireless Path (AWP)
Answer: E
Explanation:
Mesh networks are scalable outdoor networks that continuously communicate with each other to determine link paths. If a link is degraded, the AP will determine whether a better path exists and will route traffic through a more optimal node.
Intelligent wireless routing is provided by the patent-pending Adaptive Wireless Path (AWP) protocol. This enables each AP to identify its neighbors and intelligently choose the optimal path to the wired network by calculating the cost of each path in terms of signal strength and the number of hops required to get to a controller.

QUESTION NO: 40
A client is searching for an access point (AP). What is the correct process order that the client and access point go through to create a connection?
A.probe request/response, authentication request/response, association request/response
B.association request/response, authentication request/response, probe request/response
C.probe request/response, association request/response, authentication request/response
D.association request/response, probe request/response, authentication request/response
Answer: A
Explanation:
From the Cisco FAQ on Cisco Aironet Wireless Security:
What steps does Open Authentication involve for a client to associate with the AP? The client sends a probe request to the APs. The APs send back probe responses. The client evaluates the AP responses and selects the best AP. The client sends an authentication request to the AP. The AP confirms authentication and registers the client. The client then sends an association request to the AP. The AP confirms the association and registers the client.

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