Cisco 351-001 Online Practice Questions and Exam Preparation

Cisco 351-001 Online Questions & Answers

• Question 631:

  Refer to the exhibit.

  

  For which reason could a BGP-speaking device in autonomous system 65534 be prevented from installing the given route in its BGP table?

  A. The AS number of the BGP is specified in the given AS_PATH.
  B. The origin of the given route is unknown.
  C. BGP is designed only for publicly routed addresses.
  D. The AS_PATH for the specified prefix exceeds the maximum number of ASs allowed.
  E. BGP does not allow the AS number 65535.
  A. The AS number of the BGP is specified in the given AS_PATH.

  ---

  BGP is considered to be a 'Path Vector' routing protocol rather than a distance vector routing protocol since it utilises a list of AS numbers to describe the path that a packet should take. This list is called the AS_PATH. Loops are prevented because if a BGP speaking router sees it's own AS in the AS_PATH of a route it rejects the route.

• Question 632:

  What are the minimum requirements for Cisco PfR to provide routing control?

  A. one master controller, two border routers, two internal interfaces, and two external interfaces.
  B. one master controller, one border router, one internal interface, and two external interfaces.
  C. one master controller, two border router, one internal interface, and one external interface.
  D. one master controller, one border router, two internal interfaces, and one external interface.
  E. two master controllers, one border router, one internal interface, and one external interface.
  B. one master controller, one border router, one internal interface, and two external interfaces.

• Question 633:

  For which feature is the address family "rtfilter" used?

  A. Enhanced Route Refresh
  B. MPLS VPN filtering
  C. Route Target Constraint
  D. Unified MPLS
  C. Route Target Constraint

  ---

  With Multiprotocol Label Switching (MPLS) VPN, the internal Border Gateway Protocol (iBGP) peer or Route Reflector (RR) sends all VPN4 and/or VPN6 prefixes to the PE routers. The PE router drops the VPN4/6 prefixes for which there is no importing VPN routing and forwarding (VRF). This is a behavior where the RR sends VPN4/6 prefixes to the PE router, which it does not need. This is a waste of processing power on the RR and the PE and a waste of bandwidth. With Route Target Constraint (RTC), the RR sends only wanted VPN4/6 prefixes to the PE. 'Wanted' means that the PE has VRF importing the specific prefixes. RFC 4684 specifies Route Target Constraint (RTC). The support is through a new address family rtfilter for both VPNv4 and VPNv6.

  Reference: http://www.cisco.com/c/en/us/support/docs/multiprotocol-label-switching- mpls/mpls/116062-technologies-technote-restraint-00.html

• Question 634:

  Which two statements are correct about route redistribution? (Choose two)

  A. Redistributing the entire BGP table from the Internet works well when using multiple OSPF areas.
  B. iBGP is used within the AS to carry eBGP attributes that otherwise would be lost if eBGP was redistributed into IGP.
  C. The unequal cost multipath load-balancing characteristic is lost when redistributing OSPF into EIGRP.
  D. IS-IS does not support Layer 2 routes leaking into a Layer 1 domain.
  E. Mutual redistribution at multiple points can create a routing loop.
  B. iBGP is used within the AS to carry eBGP attributes that otherwise would be lost if eBGP was redistributed into IGP.
  E. Mutual redistribution at multiple points can create a routing loop.

• Question 635:

  Which statement about OSPF multiaccess segments is true?

  A. The designated router is elected first.
  B. The designated and backup designated routers are elected at the same time.
  C. The router that sent the first hello message is elected first.
  D. The backup designated router is elected first.
  D. The backup designated router is elected first.

  ---

  According to the RFC, the BDR is actually elected first, followed by the DR. The RFC explains why:

  "The reason behind the election algorithm's complexity is the desire for an orderly transition from Backup Designated Router to Designated Router, when the current Designated Router fails. This orderly transition is ensured through the

  introduction of hysteresis: no new Backup Designated Router can be chosen until the old Backup accepts its new Designated Router responsibilities.

  The above procedure may elect the same router to be both Designated Router and Backup Designated Router, although that router will never be the calculating router (Router X) itself."

  Reference: http://www.ietf.org/rfc/rfc2328.txt ?Page 76

• Question 636:

  DRAG DROP

  Drag and drop the VLAN number on the left to the corresponding default VLAN name on the right.

  Select and Place:

  

  

• Question 637:

  DRAG DROP

  Drag and drop the IS-IS component on the left to the function that it performs on the right.

  Select and Place:

  

  

• Question 638:

  Under Cisco IOS Software, which two features are supported in RADIUS Change of Authorization requests? (Choose two.)

  A. session identification
  B. session reauthentication
  C. session termination
  D. host termination
  A. session identification
  C. session termination

  ---

  CoA requests, as described in RFC 5176, are used in a pushed model to allow for session identification, host reauthentication, and session termination. The model comprises one request (CoA-Request) and two possible response codes. Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/sec_usr_aaa/configuration/15- sy/sec-usr-aaa-15-sy-book/sec-rad-coa.html

• Question 639:

  What is the function of the rendezvous point in PIM?

  A. It acts as a shared root for a multicast tree.
  B. It is the main source of the multicast traffic.
  C. It redistributes the multicast configuration to its connected neighbors.
  D. It will redistribute the unicast routes to avoid an RPF failure.
  A. It acts as a shared root for a multicast tree.

• Question 640:

  Refer to the exhibit.

  

  R2 is unable to access the 172.16.1.0/30 network between R1 and R3. Which option is a possible reason for the failure?

  A. The seed metric for redistributing into RIP on R3 is missing.
  B. The OSPF processes on R2 and R3 are different.
  C. Auto-summary is misconfigured under the RIP process of R3.
  D. The subnet mask on the link between R2 and R3 is smaller than /30.
  E. The wildcard mask on R3 is misconfigured.
  A. The seed metric for redistributing into RIP on R3 is missing.

  ---

  The problem is that RIP requires a seed metric to be specified when redistributing routes into that protocol. A seed metric is a "starter metric" that gives the RIP process a metric it can work with. The OSPF metric of cost is incomprehensible

  to RIP, since RIP's sole metric is hop count.

  Reference:

  http://www.thebryantadvantage.com/CCNP%20Certification%20BSCI%20Exam%20Tutoria l%20Route%20Redistribution%20Seed%20Metric.htm