[Free] Download New Updated (August 2016) Cisco 642-997 Real Exam 41-50

Ensurepass

QUESTION 41

Which statement about scalability in Cisco OTV is true?

 

A.

The control plane avoids flooding by exchanging MAC reachability.

B.

IP-based functionality provides Layer 3 extension over any transport.

C.

Any encapsulation overhead is avoided by using IS-IS.

D.

Unknown unicasts are handled by the authoritative edge device.

 

Correct Answer: A

Explanation:

Cisco calls the underlying concept of OTV traffic forwarding “MAC routing”, since it behaves as if you are routing Ethernet frames over the DCI transport. OTV uses a control plane protocol to proactively propagate MAC address reachability before traffic is allowed to pass, which eliminates dependency on flooding mechanism to either learn MAC addresses or forward unknown unicasts.

 

Reference: http://www.computerworld.com/article/2515468/data-center/layer-2-data-center-interconnect-options.html

 

 

QUESTION 42

What must be enabled on the interface of a multicast-enabled device to support the Source Specific Multicast feature?

 

A.

IGMP version 3

B.

IGMP version 2

C.

IGMP version 1

D.

PIM

 

Correct Answer: A

Explanation:

IGMP is the Internet Engineering Task Force (IETF) standards track protocol used for hosts to signal multicast group membership to routers. Version 3 of this protocol supports source filtering, which is required for SSM. To run SSM with IGMPv3, SSM must be supported in the Cisco IOS router, the host where the application is running, and the application itself. IGMP v3lite and URD are two Cisco-developed transition solutions that enable the immediate development and deployment of SSM services, without the need to wait for the availability of full IGMPv3 support in host operating systems and SSM receiver applications. IGMP v3lite is a solution for application developers that allows immediate development of SSM receiver applications switching to IGMPv3 as soon as it becomes available. URD is a solution for content providers and content aggregators that enables them to deploy receiver applications that are not yet SSM enabled (through support for IGMPv3). IGMPv3, IGMP v3lite, and URD interoperate with each other, so that both IGMP v3lite and URD can easily be used as transitional solutions toward full IGMPv3 support in hosts.

 

Reference: http://www.cisco.com/c/en/us/td/docs/ios/12_2/ip/configuration/guide/fipr_c/1cfssm.html

 

 

QUESTION 43

Refer to the exhibit. This multilayer Cisco Nexus switch had been the active virtual gateway for Group 1 before it became temporarily unavailable. What will happen to GLBP Group 1 when this device becomes available again?

 

clip_image002

 

A.

The currently active router remains active.

B.

It depends on the priority value that is configured active on the router.

C.

The Cisco Nexus switch becomes the active virtual gateway after 600 seconds.

D.

It depends on the weighting values that are configured active on the router.

 

Correct Answer: A

Explanation:

GLBP prioritizes gateways to elect an active virtual gateway (AVG). If multiple gateways have the same priority, the gateway with the highest real IP address becomes the AVG. The AVG assigns a virtual MAC address to each member of the GLBP group. Each member is the active virtual forwarder (AVF) for its assigned virtual MAC address, forwarding packets sent to its assigned virtual MAC address.

 

The AVG also answers Address Resolution Protocol (ARP) requests for the virtual IP address. Load sharing is achieved when the AVG replies to the ARP requests with different virtual MAC addresses.

 

Note: Packets received on a routed port destined for the GLBP virtual IP address terminate on the local router, regardless of whether that router is the active GLBP router or a redundant GLBP router. This termination includes ping and Telnet traffic. Packets received on a Layer 2 (VLAN) interface destined for the GLBP virtual IP address terminate on the active router.

 

 

QUESTION 44

What is an Overlay Transport Virtualization extended VLAN?

 

A.

the VLAN used to locate other AEDs

B.

the VLAN used to access the overlay network by the join interface

C.

the user VLAN that exists in multiple sites

D.

the VLAN that must contain the overlay interface

 

Correct Answer: C

Explanation:

Functions of OTV

Maintains a list of overlays

Maintains a list of configured overlay parameters such as name, multicast address, encapsulation type, authentication, and OTV feature sets

Maintains the state of the overlay interface

Maintains the status of OTV VLAN membership from Ethernet infrastructure and the state of the authoritative edge device (AED) from IS-IS

Maintains a database of overlay adjacencies as reported by IS-IS

Maintains IP tunnel information and manages the encapsulation for data sent on the overlay network

Manages delivery groups (DGs) for each overlay by snooping multicast traffic and monitoring traffic streams for active DGs

Configures, starts, and stops the OTV IS-IS instance

Interfaces with IP multicast to join provider multicast groups for each overlay

 

 

QUESTION 45

Which two issues explain why a packet is not being routed as desired in a policy-based routing configuration? (Choose two.)

 

A.

The route map is not applied to the egress interface.

B.

The route map is not applied to the ingress interface.

C.

The next hop that is configured in the route map is not in the global routing table.

D.

The next hop that is configured in the route map has a higher metric than the default next hop.

 

Correct Answer: CD

Explanation:

The next hop that is configured in the route map is not in the global routing table then the packet will not be forwarded as desired. The next hop that is configured in the route map has a higher metric than the default next hop.

 

 

QUESTION 46

Which two statements about implementing Cisco NPV and NPIV on a Cisco Nexus 5000 Series switch are true? (Choose two.)

 

A.

STP must run inside the FP network.

B.

All VLANs must be in the same mode, CE, or FP.

C.

FP port can join the private and nonprivate VLANs.

D.

Only F and M seri
es modules can run FabricPath.

E.

These require an enhanced Layer 2 license to run.

Correct Answer: BE

Explanation:

With the Nexus 5×00 switch, FCoE functionality is a licensed feature. After the license is installed, FCoE configuration can be completed.

Reference: http://www.ciscopress.com/articles/article.asp?p=2030048&seqNum=4

 

 

QUESTION 47

DRAG DROP

Drag the security description on the left to the appropriate security feature on the right.

 

clip_image004

 

Correct Answer:

clip_image006

 

 

QUESTION 48

Which policy-map action performs congestion avoidance?

 

A.

priority

B.

bandwidth

C.

queue-limit

D.

random-detect

 

Correct Answer: D

Explanation:

Congestion avoidance techniques monitor network traffic loads in an effort to anticipate and avoid congestion at common network bottlenecks. Congestion avoidance is achieved through packet dropping. Among the more commonly used congestion avoidance mechanisms is Random Early Detection (RED), which is optimum for high-speed transit networks. Cisco IOS QoS includes an implementation of RED that, when configured, controls when the router drops packets. If you do not configure Weighted Random Early Detection (WRED), the router uses the cruder default packet drop mechanism called tail drop.

 

Reference: h
ttp://www.cisco.com/c/en/us/td/docs/ios/12_2/qos/configuration/guide/fqos_c/qcfconav.html

 

 

QUESTION 49

What is the Overlay Transport Virtualization site VLAN used for?

 

A.

to allow the join interfaces at different sites to communicate

B.

to detect devices at the site that are not capable of OTV

C.

to allow multiple site AEDs to communicate with each other

D.

to detect other OTV edge devices in the site

 

Correct Answer: D

Explanation:

The edge device performs OTV functions: it receives the Layer 2 traffic for all VLANs that need to be extended to remote locations and dynamically encapsulates the Ethernet frames into IP packets that are then sent across the transport infrastructure. It is expected that at least two OTV edge devices are deployed at each data center site to improve the resiliency.

 

Reference: http://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/Data_Center/DCI/whitepaper/DCI3_OTV_Intro/DCI_1.html

 

 

QUESTION 50

Which feature enables NIV?

 

A.

EHV

B.

vPC

C.

Cisco FabricPath

D.

Cisco OTV

E.

VN-Tag

 

Correct Answer: A

Explanation:

EHV is the feature that enables NIV.

 

Free VCE & PDF File for Cisco 642-997 Real Exam

Instant Access to Free VCE Files: CCNA | CCNP | CCIE …
Instant Access to Free PDF Files: CCNA | CCNP | CCIE …