Cisco 351-001 Online Practice Questions and Exam Preparation

Cisco 351-001 Online Questions & Answers

• Question 31:

  Which three values can you use to configure an ERSPAN destination session? (Choose three.)

  A. VLAN ID
  B. source IP address
  C. destination IP address
  D. ID number
  E. VRF
  F. session name
  B. source IP address
  D. ID number
  E. VRF

• Question 32:

  Which statement about NAT64 is true?

  A. NAT64 provides address family translation and translates IPv4 to IPv6 and IPv6 to IPv4.
  B. NAT64 provides address family translation and can translate only IPv6 to IPv4.
  C. NAT64 should be considered as a permanent solution.
  D. NAT64 requires the use of DNS64.
  A. NAT64 provides address family translation and translates IPv4 to IPv6 and IPv6 to IPv4.

• Question 33:

  Which three features are supported by PIMv6? (Choose three)

  A. embedded RP
  B. MSDP
  C. Auto-RP
  D. sparse mode
  E. SSM
  F. dense mode
  A. embedded RP
  D. sparse mode
  E. SSM

• Question 34:

  What are three benefits of deploying NAT with ALG? (Choose three.)

  A. the use of dynamic ephemeral ports through a firewall
  B. the synchronization of translations between multiple streams of data
  C. the use of deep packet inspection
  D. the use of static ephemeral ports through a firewall
  E. the conversion of session layer addresses from the application payload to outside global addresses
  F. NAT traversal to support asymmetric data sessions
  A. the use of dynamic ephemeral ports through a firewall
  B. the synchronization of translations between multiple streams of data
  C. the use of deep packet inspection

• Question 35:

  What is the VLAN ID range of VLANs that are eligible for pruning?

  A. 2 through 1001
  B. 1 through 1005
  C. 1 through 4096
  D. 2 through 1005
  A. 2 through 1001

• Question 36:

  What is the purpose of Route Target Constraint?

  A. to avoid using route reflectors in MPLS VPN networks
  B. to avoid using multiple route distinguishers per VPN in MPLS VPN networks
  C. to be able to implement VPLS with BGP signaling
  D. to avoid sending unnecessary BGP VPNv4 or VPNv6 updates to the PE router
  E. to avoid BGP having to perform route refreshes
  D. to avoid sending unnecessary BGP VPNv4 or VPNv6 updates to the PE router

  ---

  Some service providers have a very large number of routing updates being sent from RRs to PEs, using considerable resources. A PE does not need routing updates for VRFs that are not on the PE; therefore, the PE determines that many

  routing updates it receives are "unwanted." The PE can filter out the unwanted updates using Route Target Constraint.

  Reference:

  http://www.cisco.com/c/en/us/td/docs/ios/ios_xe/iproute_bgp/configuration/guide/2_xe/irg_x e_book/irg_rt_filter_xe.html.

• Question 37:

  In a PfR environment, which two statements best describe the difference between active mode monitoring and fast mode monitoring? (Choose two.)

  A. Active mode monitoring can monitor and measure actual traffic via NetFlow data collection.
  B. Fast mode monitoring can measure bursty traffic better than active mode.
  C. Active mode monitoring uses IP SLA probes for the purpose of obtaining performance characteristics of the current WAN exit link.
  D. Fast mode monitoring uses IP SLA probes via all valid exits continuously to quickly determine an alternate exit link.
  C. Active mode monitoring uses IP SLA probes for the purpose of obtaining performance characteristics of the current WAN exit link.
  D. Fast mode monitoring uses IP SLA probes via all valid exits continuously to quickly determine an alternate exit link.

  ---

  Active Monitoring PfR uses Cisco IOS IP Service Level Agreements (SLAs) to enable active monitoring. IP SLAs support is enabled by default. IP SLAs support allows PfR to be configured to send active probes to target IP addresses to measure the jitter and delay, determining if a prefix is out-of-policy and if the best exit is selected. The border router collects these performance statistics from the active probe and transmits this information to the master controller.

  Fast Failover Monitoring Fast failover monitoring enables passive and active monitoring and sets the active probes to continuously monitor all the exits (probe-all). Fast failover monitoring can be used with all types of active probes: Internet Control Message Protocol (ICMP) echo, jitter, TCP connection, and UDP echo.

  Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/pfr/command/pfr-cr-book/pfr- s1.html

• Question 38:

  When BGP route reflectors are used, which attribute ensures that a routing loop is not created?

  A. weight
  B. local preference
  C. multiexit discriminator
  D. originator ID
  D. originator ID

  ---

  As the iBGP learned routes are reflected, routing information may loop. The route reflector model has the following mechanisms to avoid routing loops:

  Originator ID is an optional, nontransitive BGP attribute. It is a 4-byte attributed created by a route reflector. The attribute carries the router ID of the originator of the route in the local autonomous system. Therefore, if a misconfiguration causes routing information to come

  back to the originator, the information is ignored. ? Cluster-list is an optional, nontransitive BGP attribute. It is a sequence of cluster IDs that the route has passed. When a route reflector reflects a route from its clients to nonclient peers, and vice versa, it appends the local cluster ID to the cluster-list. If the cluster-list is empty, a new cluster-list is created. Using this attribute, a route reflector can identify if routing information is looped back to the same cluster due to misconfiguration. If the local cluster ID is found in the cluster-list, the advertisement is ignored.

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

• Question 39:

  Which two statements about the spanning-tree timers in a switched network are true? (Choose two)

  A. After receiving a BPDU from the root bridge, a non-root bridge waits for the hello interval before forwarding it out.
  B. The root bridge sends out a TCN every max-age interval.
  C. The root bridge sends out a configuration BPDU every hello interval.
  D. The default hello time is two seconds.
  C. The root bridge sends out a configuration BPDU every hello interval.
  D. The default hello time is two seconds.

• Question 40:

  Refer to the exhibit.

  

  Which two statements about this route table are true? (Choose two.)

  A. The BGP routes are internal.
  B. The OSPF routes with the E2 flag retain the same metric as they leave the router.
  C. The OSPF routes with the IA flag have their administrative distances incremented as they leave the router.
  D. The BGP routes are external.
  E. The OSPF routes with the E2 flag have their metrics incremented as they leave the router.
  A. The BGP routes are internal.
  B. The OSPF routes with the E2 flag retain the same metric as they leave the router.

  ---

  IBGP routes have an Administrative distance of 200, while EBGP have an AD of 20. Here we see that the BGP routes have an AD value of 200. With OSPF, external routes fall under two categories, external type 1 and external type 2. The difference between the two is in the way the cost (metric) of the route is being calculated. The cost of a type 2 route is always the external cost, irrespective of the interior cost to reach that route. A type 1 cost is the addition of the external cost and the internal cost used to reach that route. The metric for E2 routes do not change when advertising to other routers.