Cisco 351-001 Online Practice Questions and Exam Preparation

Cisco 351-001 Online Questions & Answers

• Question 451:

  Which command enables L2 QoS support in all VLANs (including the native VLAN)?

  A. switchport priority extend cos
  B. mls qos trust dscp
  C. mls qos rewrite ip dscp
  D. switchport trunk native vlan tag
  D. switchport trunk native vlan tag

  ---

  You can enter the switchport trunk native vlan tag command to enable the tagging of native VLAN traffic on a per-port basis. When tagging is enabled, all the packets on the native VLAN are tagged and all incoming untagged data packets are dropped, but untagged control packets are accepted. When tagging is enabled, it will allow for L2 QoS support in all VLANs, including the native VLAN.

• Question 452:

  Which two statements about Metro Ethernet services are true? (Choose two.)

  A. EPL is a point-to-point service from one customer site to another across an MPLS backbone.
  B. EVPL is a multipoint service that emulates a LAN over an MPLS backbone.
  C. EPLAN is a multipoint service that emulates a LAN over an MPLS backbone.
  D. EVPL is a point-to-point service from one customer site to another across an MPLS backbone.
  E. ELAN is a point-to-point service from one customer site to another across an MPLS backbone.
  F. EVPL is a multipoint service with a root node that is suitable for multicast services.
  A. EPL is a point-to-point service from one customer site to another across an MPLS backbone.
  B. EVPL is a multipoint service that emulates a LAN over an MPLS backbone.

• Question 453:

  Which CoS value is mapped to DSCP 48 by default?

  A. 6
  B. 7
  C. AF21
  D. AF44
  E. AF41
  F. 46
  A. 6

• Question 454:

  Refer to the exhibit.

  

  Which two statements are true? (Choose two.)

  A. This is the output of the show ip ospf command.
  B. This is the output of the show ip protocols command.
  C. This router is an ABR.
  D. This router is an ASBR.
  E. Authentication is not configured for the area.
  A. This is the output of the show ip ospf command.
  E. Authentication is not configured for the area.

  ---

  The following is sample output from the show ip ospf command when entered without a specific OSPF process ID with no authentication.

  Router# show ip ospf

  Routing Process "ospf 201" with ID 10.0.0.1 and Domain ID 10.20.0.1 Supports only single TOS(TOS0) routes Supports opaque LSA SPF schedule delay 5 secs, Hold time between two SPFs 10 secs Minimum LSA interval 5 secs. Minimum LSA arrival 1 secs LSA group pacing timer 100 secs Interface flood pacing timer 55 msecs Retransmission pacing timer 100 msecs Number of external LSA 0. Checksum Sum 0x0 Number of opaque AS LSA 0. Checksum Sum 0x0 Number of DCbitless external and opaque AS LSA 0 Number of DoNotAge external and opaque AS LSA 0 Number of areas in this router is 2. 2 normal 0 stub 0 nssa External flood list length 0 Area BACKBONE(0) Number of interfaces in this area is 2 Area has no authentication SPF algorithm executed 4 times Area ranges are Number of LSA 4. Checksum Sum 0x29BEB Number of opaque link LSA 0. Checksum Sum 0x0 Number of DCbitless LSA 3 Number of indication LSA 0 Number of DoNotAge LSA 0 Flood list length 0

  Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_ospf/command/iro-cr- book/ospf-s1.html#wp8749965360

• Question 455:

  Refer to the exhibit.

  

  If the remaining configuration uses default values, what is the expected output of the show mls qos queue-set command?

  E. Exhibit A
  F. Exhibit B
  G. Exhibit C
  H. Exhibit D
  A

  ---

  mls qos queue-set output qset-idthreshold queue-id drop-threshold1 drop-threshold2 reserved-threshold maximum-threshold Configure the WTD thresholds, guarantee the availability of buffers, and configure the maximum memory allocation

  for the queue-set (four egress queues per port). By default, the WTD thresholds for queues 1, 3, and 4 are set to 100 percent. The thresholds for queue 2 are set to 200 percent. The reserved thresholds for queues 1, 2, 3, and 4 are set to 50

  percent. The maximum thresholds for all queues are set to 400 percent. For qset-id , enter the ID of the queue-set specified in Step 2. The range is 1 to 2. For queue-id , enter the specific queue in the queue-set on which the command is

  performed. The range is 1 to 4. For drop-threshold1 drop-threshold2 , specify the two WTD thresholds expressed as a percentage of the queue's allocated memory. Th e range is 1 to 3200 percent. For reserved-threshold , enter the amount of

  memory to be guaranteed (reserved) for the queue expressed as a percentage of the allocated memory. The range is 1 to 100 percent.

  For maximum-threshold , enable a queue in the full condition to obtain more buffers than are reserved for it. This is the maximum memory the queue can have before the packets are dropped if the common pool is not empty. The range is 1 to

  3200 percent

  Reference:

  http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3750x_3560x/software/release/1 2-2_55_se/configuration/guide/3750xscg/swqos.html

• Question 456:

  Which two statements about the default behavior of IS-IS are true? (Choose two.)

  A. The default IS-IS router type is L1/L2.
  B. The default IS-IS metric type is wide.
  C. The default IS-IS interface circuit type is L1/L2.
  D. By default, two IS-IS routers must use the same hello interval and hold timer in order to become neighbors.
  A. The default IS-IS router type is L1/L2.
  C. The default IS-IS interface circuit type is L1/L2.

• Question 457:

  Which action does route poisoning take that serves as a loop-prevention method?

  A. It immediately sends routing updates with an unreachable metric to all devices.
  B. It immediately sends routing updates with a metric of 255 to all devices.
  C. It prohibits a router from advertising back onto the interface from which it was learned.
  D. It advertises a route with an unreachable metric back onto the interface from which it was learned.
  E. It poisons the route by tagging it uniquely within the network.
  A. It immediately sends routing updates with an unreachable metric to all devices.

  ---

  With route poisoning, when a router detects that one of its connected routes has failed, the router will poison the route by assigning an infinite metric to it and advertising it to neighbors.

• Question 458:

  Which three statements about EIGRP wide metrics are true? (Choose three.)

  A. The maximum metric is 65536.
  B. The default delay is 1,000,000 picoseconds.
  C. They allow up to 100 hops.
  D. They allow up to 256 hops.
  E. The default delay is 1,000,000 milliseconds.
  F. The maximum metric is 51200.
  A. The maximum metric is 65536.
  B. The default delay is 1,000,000 picoseconds.
  C. They allow up to 100 hops.

• Question 459:

  Which statement describes the function of rekey messages?

  A. They prevent unencrypted traffic from passing through a group member before registration.
  B. They refresh IPsec SAs when the key is about to expire.
  C. They trigger a rekey from the server when configuring the rekey ACL.
  D. They authenticate traffic passing through a particular group member.
  B. They refresh IPsec SAs when the key is about to expire.

  ---

  Rekey messages are used to refresh IPsec SAs. When the IPsec SAs or the rekey SAs are about to expire, one single rekey message for a particular group is generated on the key server. No new IKE sessions are created for the rekey message distribution. The rekey messages are distributed by the key server over an existing IKE SA. Rekeying can use multicast or unicast messages.

  Reference: http://www.cisco.com/c/en/us/td/docs/ios- xml/ios/sec_conn_getvpn/configuration/xe-3s/sec-get-vpn-xe-3s-book/sec-get-vpn.html

• Question 460:

  Which statement is true about conditional advertisements?

  A. Conditional advertisements create routes when a predefined condition is met.
  B. Conditional advertisements create routes when a predefined condition is not met.
  C. Conditional advertisements delete routes when a predefined condition is met.
  D. Conditional advertisements create routes and withhold them until a predefined condition is met.
  E. Conditional advertisements do not create routes, they only withhold them until a predefined condition is met.
  E. Conditional advertisements do not create routes, they only withhold them until a predefined condition is met.

  ---

  The Border Gateway Protocol (BGP) conditional advertisement feature provides additional control of route advertisement, depending on the existence of other prefixes in the BGP table.

  Normally, routes are propagated regardless of the existence of a different path. The BGP conditional advertisement feature uses the non-exist-map and the advertise-map keywords of the neighbor advertise-map command in order to track

  routes by the route prefix. If a route prefix is not present in output of the non- exist-map command, then the route specified by the advertise-map command is announced. This feature is useful for multihomed networks, in which some prefixes

  are advertised to one of the providers only if information from the other provider is not present (this indicates a failure in the peering session or partial reachability).

  Reference: http://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol- bgp/16137-cond-adv.html