Cisco 642-997 Online Practice Questions and Exam Preparation

Cisco 642-997 Online Questions & Answers

• Question 91:

  Which statement explains why a Cisco UCS 6200 Fabric Interconnect that is configured in end-host mode is beneficial to the unified fabric network?

  A. There is support for multiple (power of 2) uplinks.
  B. Upstream Layer 2 disjoint networks will remain separated.
  C. The 6200 can connect directly via vPC to a Layer 3 aggregation device.
  D. STP is not required on the uplink ports from the 6200.
  D. STP is not required on the uplink ports from the 6200.

  ---

  In Cisco Unified Computing System environments, two Ethernet switching modes determine the way that the fabric interconnects behave as switching devices between the servers and the network. In end-host mode, the fabric interconnects appear to the upstream devices as end hosts with multiple links. In end-host mode, the switch does not run Spanning Tree Protocol and avoids loops by following a set of rules for traffic forwarding. In switch mode, the switch runs Spanning Tree Protocol to avoid loops, and broadcast and multicast packets are handled in the traditional way.

  http://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/unified- computing/whitepaper_c11-701962.html

• Question 92:

  Which two statements about SAN zoning on Cisco Nexus switches are true? (Choose two.)

  A. Zoning is enforced by examining the destination ID field.
  B. Devices can only belong to one zone.
  C. Only one zone set can be activated at any time.
  D. A zone can only be a member one zone set.
  E. Zoning must be administered from the primary SAN switch in the fabric.
  F. Zone configuration changes are nondisruptive.
  C. Only one zone set can be activated at any time.
  F. Zone configuration changes are nondisruptive.

  ---

  A zone set can be activated or deactivated as a single entity across all switches in the fabric. Only one zone set can be activated at any time. If zoning is not activated, all devices are members of the default zone. If zoning is activated, any device that is not in an active zone (a zone that is part of an active zone set) is a member of the default zone. Zoning can be administered from any switch in the fabric. When you activate a zone (from any switch), all switches in the fabric receive the active zone set. Additionally, full zone sets are distributed to all switches in the fabric, if this feature is enabled in the source switch. Reference: http://www.cisco.com/en/US/docs/storage/san_switches/mds9000/sw/san- os/quick/ guide/qcg_zones.html

• Question 93:

  How does addition of bandwidth between spine and leaf switches in a FabricPath architecture get utilized?

  A. Links between the same set of switches are automatically added to a port channel.
  B. Adding additional bandwidth is handled dynamically using the 802.1AX protocol.
  C. Traffic is load shared automatically across the available paths to the destination.
  D. FabricPath uses hardware bonding of physical interfaces to form higher-speed links.
  C. Traffic is load shared automatically across the available paths to the destination.

• Question 94:

  Which three parameters can be set when configuring a Cisco MDS 9000 Series Switch to use a TACACS+ server? (Choose three.)

  A. group-size
  B. deadtime
  C. timeout
  D. keep-alive
  E. retransmit
  B. deadtime
  C. timeout
  E. retransmit

• Question 95:

  Which two RFCs are supported by Cisco NX-OS devices for OSPFv2? (Choose two.)

  A. RFC 2238
  B. RFC 1918
  C. RFC 1583
  D. RFC 2453
  E. RFC 2740
  A. RFC 2238
  C. RFC 1583

• Question 96:

  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
  A. IGMP version 3

  ---

  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 97:

  Which statement about the MPLS feature set is true?

  A. It is not license dependent.
  B. It can be installed from any VDC.
  C. It can be enabled only in the default VDC.
  D. It must be installed from the default VDC.
  D. It must be installed from the default VDC.

• Question 98:

  Which two reasons explain why a server on VLAN 10 is unable to join a multicast stream that originates on VLAN 20? (Choose two.)

  A. IGMP snooping and mrouter are not enabled on VLAN 10.
  B. VLAN 20 has no IGMP snooping querier defined and VLAN 10 has no mrouter.
  C. The mrouter on VLAN 20 does not see the PIM join.
  D. The mrouter must be on VLAN 10 and VLAN 20.
  A. IGMP snooping and mrouter are not enabled on VLAN 10.
  C. The mrouter on VLAN 20 does not see the PIM join.

  ---

  IGMP snooping is a mechanism to constrain multicast traffic to only the ports that have receivers attached. The mechanism adds efficiency because it enables a Layer 2 switch to selectively send out multicast packets on only the ports that

  need them. Without IGMP snooping, the switch floods the packets on every port. The switch "listens" for the exchange of IGMP messages by the router and the end hosts. In this way, the switch builds an IGMP snooping table that has a list of

  all the ports that have requested a particular multicast group.

  The mrouter port is simply the port from the switch point of view that connects to a multicast router. The presence of at least one mrouter port is absolutely essential for the IGMP snooping operation to work across switches.

  All Catalyst platforms have the ability to dynamically learn about the mrouter port. The switches passively listen to either the Protocol Independent Multicast (PIM) hellos or the IGMP query messages that a multicast router sends out

  periodically.

  Reference: http://www.cisco.com/c/en/us/support/docs/switches/catalyst-6500-series- switches/68131-cat-multicast-prob.html

• Question 99:

  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.
  A. The control plane avoids flooding by exchanging MAC reachability.

  ---

  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 100:

  Which protocol is responsible for the discovery of FCoE capabilities on a remote switch?

  A. DCE
  B. DCBx
  C. CDP
  D. LLDP
  B. DCBx

  ---

  Data Center Bridging Capabilities Exchange Protocol (DCBX): a discovery and capability exchange protocol that is used for conveying capabilities and configuration of the above features between neighbors to ensure consistent configuration across the network. This protocol leverages functionality provided by IEEE 802.1AB (LLDP). It is actually included in the 802.1az standard.

  Reference: http://en.wikipedia.org/wiki/Data_center_bridging