Cisco 351-001 Online Practice Questions and Exam Preparation

Cisco 351-001 Online Questions & Answers

• Question 231:

  Which authentication method does OSPFv3 use to secure communication between neighbors?

  A. plaintext
  B. MD5 HMAC
  C. PKI
  D. IPSec
  D. IPSec

  ---

  In order to ensure that OSPFv3 packets are not altered and re-sent to the device, causing the device to behave in a way not desired by its system administrators, OSPFv3 packets must be authenticated. OSPFv3 uses the IPsec secure socket API to add authentication to OSPFv3 packets. This API supports IPv6. OSPFv3 requires the use of IPsec to enable authentication. Crypto images are required to use authentication, because only crypto images include the IPsec API needed for use with OSPFv3.

  Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_ospf/configuration/15- sy/iro-15-sy-book/ip6-route-ospfv3-auth-ipsec.html

• Question 232:

  Where is multicast traffic sent, when it is originated from a spoke site in a DMVPN phase 2 cloud?

  A. spoke-spoke
  B. nowhere, because multicast does not work over DMVPN
  C. spoke-spoke and spoke-hub
  D. spoke-hub
  D. spoke-hub

  ---

  Spokes map multicasts to the static NBMA IP address of the hub, but hub maps multicast packets to the "dynamic" mappings ?that is, the hub replicates multicast packets to all spokes registered via NHRP, so multicast traffic is sent to the hub from a spoke instead of to the other spokes directly.

• Question 233:

  Which option is an incorrect design consideration when deploying OSPF areas?

  A. area 1 - area 0 - MPLS VPN backbone - area 0 - area 2
  B. area 1 - MPLS VPN backbone - area 2
  C. area 1 - MPLS VPN backbone - area 1
  D. area 2 - area 0 - MPLS VPN backbone - area 1
  E. area 0 - area 2 - MPLS VPN superbackbone - area 1
  E. area 0 - area 2 - MPLS VPN superbackbone - area 1

  ---

  In the case of MPLS-VPN Backbone as The OSPF superbackbone behaves exactly like Area 0 in regular OSPF, so we cannot have two different area 0's that are not directly connected to each other. When area 0 connects to the superbackbone, it simply becomes an extension of area 0.

• Question 234:

  Which statement about the feasible distance in EIGRP is true?

  A. It is the maximum metric that should feasibly be considered for installation in the RIB.
  B. It is the minimum metric to reach the destination as stored in the topology table.
  C. It is the metric that is supplied by the best next hop toward the destination.
  D. It is the maximum metric possible based on the maximum hop count that is allowed.
  B. It is the minimum metric to reach the destination as stored in the topology table.

  ---

  An EIGRP router advertises each destination it can reach as a route with an attached metric. This metric is called the route's reported distance (the term advertised distance has also been used in older documentation). A successor route for any given destination is chosen as having the lowest computed feasible distance; that is, the lowest sum of reported distance plus the cost to get to the advertising router. By default, an EIGRP router will store only the route with the best (lowest) feasible distance in the routing table (or, multiple routes with equivalent feasible distances).

  Reference: http://packetlife.net/blog/2010/aug/9/eigrp-feasible-successor-routes/

• Question 235:

  Refer to the exhibit.

  

  How many LSDBs will router A have?

  B. 1
  C. 2
  D. 3
  D. 3

• Question 236:

  DRAG DROP

  Drag and drop the argument of the mpls ip cef load-sharing command on the left to the function it performs on the right.

  Select and Place:

  

  

• Question 237:

  Which switching technology can be used to solve reliability problems in a switched network?

  A. fragment-free mode
  B. cut-through mode
  C. check mode
  D. store-and-forward mode
  D. store-and-forward mode

  ---

  Characteristics of Store-and-Forward Ethernet Switching This section provides an overview of the functions and features of store-and-forward Ethernet switches. Error Checking Figure 1 shows a store-and-forward switch receiving an Ethernet frame in its entirety. At the end of that frame, the switch will compare the last field of the datagram against its own frame-check-sequence (FCS) calculations, to help ensure that the packet is free of physical and data-link errors. The switch then performs the forwarding process. Whereas a store-and-forward switch solves reliability issues by dropping invalid packets, cut-through devices forward them because they do not get a chance to evaluate the FCS before transmitting the packet.

  Figure 1. Ethernet Frame Entering a Store-and-Forward Bridge or Switch (from Left to Right)

  

  Reference: http://www.cisco.com/c/en/us/products/collateral/switches/nexus-5020- switch/white_paper_c11-465436.html

• Question 238:

  DRAG DROP

  Drag and drop the NAT operations on the left into the correct sequential order on the right.

  Select and Place:

  

  

• Question 239:

  Which statement describes the effect of the configuration line redistribute maximum-prefix 1500 90 withdraw?

  A. After the 1500th route is redistributed, a warning is posted in the log file and 90 more routes are redistributed before further routes are discarded.
  B. After the 1350th route is redistributed, a warning is posted in the log file until the 1500th route is redistributed, and then further routes are discarded.
  C. After the 1500th route is redistributed, further routes are discarded only if the CPU is above 90%.
  D. The routing protocol receives 1500 routes. After the routing process has redistributed 90% of the routes, the process supernets routes and injects a NULL route to prevent black- hole routing.
  B. After the 1350th route is redistributed, a warning is posted in the log file until the 1500th route is redistributed, and then further routes are discarded.

• Question 240:

  Which statement about LISP encapsulation in an EIGRP OTP implementation is true?

  A. OTP uses LISP encapsulation for dynamic multipoint tunneling.
  B. OTP maintains the LISP control plane.
  C. OTP uses LISP encapsulation to obtain routes from neighbors.
  D. LISP learns the next hop.
  A. OTP uses LISP encapsulation for dynamic multipoint tunneling.