Cisco 351-001 Online Practice Questions and Exam Preparation

Cisco 351-001 Online Questions & Answers

• Question 981:

  Which VPN technology requires the use of an external key server?

  A. GETVPN
  B. GDOI
  C. SSL
  D. DMVPN
  E. IPsec
  F. L2TPv3
  A. GETVPN

  ---

  A GETVPN deployment has primarily three components, Key Server (KS), Group Member (GM), and Group Domain of Interpretation (GDOI) protocol. GMs do encrypt/decrypt the traffic and KS distribute the encryption key to all the group members. The KS decides on one single data encryption key for a given life time. Since all GMs use the same key, any GM can decrypt the traffic encrypted by any other GM. GDOI protocol is used between the GM and KS for group key and group SA management. Minimum one KS is required for a GETVPN deployment.

  Reference: http://www.cisco.com/c/en/us/products/collateral/security/group-encrypted- transport-vpn/deployment_guide_c07_554713.html

• Question 982:

  Which group of neighbors can be configured as a BGP peer group?

  A. a group of iBGP neighbors that have the same outbound route policies
  B. a group of iBGP and eBGP neighbors that have the same inbound distribute-list
  C. a group of eBGP neighbors in the same autonomous system that have different outbound route policies
  D. a group of iBGP neighbors that have different outbound route policies
  A. a group of iBGP neighbors that have the same outbound route policies

  ---

  You can group BGP neighbors who share the same outbound policies together in what is called a BGP peer group. Instead of configuring each neighbor with the same policy individually, a peer group allows you to group the policies which can be applied to individual peers thus making efficient update calculation along with simplified configuration.

  Reference: http://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol- bgp/13755-29.html

• Question 983:

  Which two statements about OSPF route types are true? (Choose two.)

  A. The cost of an external type 2 route is the sum of the external and internal costs.
  B. The cost of an external type 2 route is the same as the external cost.
  C. Intra-area routes originate outside of their area.
  D. Inter-area routes originate inside their area.
  E. The cost of an external type 1 route is the same as the internal cost.
  F. For routes to the same destination, external type 1 routes are preferred over external type 2 routes.
  B. The cost of an external type 2 route is the same as the external cost.
  F. For routes to the same destination, external type 1 routes are preferred over external type 2 routes.

  ---

  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. A type 1 route is always preferred over a type 2 route for the same destination.

  Reference: http://www.cisco.com/c/en/us/support/docs/ip/open-shortest-path-first- ospf/7039-1.html

• Question 984:

  In which 802.1D port state are the root bridge, the root port, and the designated port(s) elected?

  A. Listening
  B. learning
  C. forwarding
  D. blocking
  E. disabled
  A. Listening

  ---

  STP switch port states:

  Blocking ?A port that would cause a switching loop if it were active. No user data is sent or received over a blocking port, but it may go into forwarding mode if the other links in use fail and the spanning tree algorithm determines the port may

  transition to the forwarding state. BPDU data is still received in blocking state.

  Prevents the use of looped paths.

  Listening ?The switch processes BPDUs and awaits possible new information that would cause it to return to the blocking state. It does not populate the MAC address table and it does not forward frames. In this state the root bridge, the root

  port, and the designated port(s) are elected. Learning ?While the port does not yet forward frames it does learn source addresses from frames received and adds them to the filtering database (switching database). It populates the MAC

  Address table, but does not forward frames. Forwarding ?A port receiving and sending data, normal operation. STP still monitors incoming BPDUs that would indicate it should return to the blocking state to prevent a loop. Disabled ?Not

  strictly part of STP, a network administrator can manually disable a port.

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

• Question 985:

  Refer to the exhibit.

  

  Which device role could have generated this debug output?

  A. an NHS only
  B. an NHC only
  C. an NHS or an NHC
  D. a DMVPN hub router
  B. an NHC only

  ---

  NHRP works off a server/client relationship, where the NHRP clients (let's call them next hop clients/NHCs) register with their next hop server (NHS), it's the responsibility of the NHS to track all of its NHCs this is done with registration request and reply packets. Here we see a registration request, which can only be sent by an NHC.

• Question 986:

  Which two statements are true about DAI? (Choose two)

  A. A valid binding in the database takes precedence over an ARP ACL.
  B. The switch intercepts and checks ARP traffic on trusted and untrusted ports.
  C. DAI uses the ARP table to determine the validity of the IP to MAC bindings.
  D. DAI ensures that only valid ARP requests and responses are relayed.
  E. DAI uses the DHCP snooping binding database to determine the validity of the IP to MAC bindings.
  D. DAI ensures that only valid ARP requests and responses are relayed.
  E. DAI uses the DHCP snooping binding database to determine the validity of the IP to MAC bindings.

• Question 987:

  Which two statements about RIPng are true? (Choose two.)

  A. RIPng can support as many as 8 equal-cost routes.
  B. RIPng can support aa many as 32 equal-cost routes.
  C. 16 is the maximum metric it can advertise.
  D. Both inbound and outbound route filtering can be implemented on a single interface,
  E. A route with a metric of 15 is advertised as unreachable.
  C. 16 is the maximum metric it can advertise.
  D. Both inbound and outbound route filtering can be implemented on a single interface,

• Question 988:

  Refer to the exhibit.

  

  Which two options are two problems that can occur with this configuration? (Choose two)

  A. The MPLS path from R1 to R5 becomes unreachable.
  B. R1 and R5 are unable to establish an LDP relationship.
  C. The label for the R1 loopback address is filtered from other MPLS routers.
  D. The label for the R5 loopback address is filtered from other MPLS routers.
  E. MPLS traffic from R1 to R5 takes a suboptimal path.
  A. The MPLS path from R1 to R5 becomes unreachable.
  D. The label for the R5 loopback address is filtered from other MPLS routers.

• Question 989:

  Which two loop-prevention mechanisms are implemented in BGP? (Choose two.)

  A. A route with its own AS in the AS_PATH is dropped automatically if the route reenters its own AS.
  B. A route with its own cluster ID in the CLUSTER_LIST is dropped automatically when the route reenters its own AS.
  C. The command bgp allowas-in enables a route with its own AS_PATH to be dropped when it reenters its own AS.
  D. The command bgp bestpath as-path ignore enables the strict checking of AS_PATH so that they drop routes with their own AS in the AS_PATH.
  E. The command bgp bestpath med missing-as-worst assigns the smallest possible MED, which directly prevents a loop.
  A. A route with its own AS in the AS_PATH is dropped automatically if the route reenters its own AS.
  B. A route with its own cluster ID in the CLUSTER_LIST is dropped automatically when the route reenters its own AS.

  ---

  When dealing with the possibility of routing updates making their way back into an AS, BGP relies on the information in the AS_path for loop detection. An update that tries to make its way back into the AS it was originated from will be dropped by the border router. With the introduction of route reflectors, there is a potential for having routing loops within an AS. A routing update that leaves a cluster might find its way back inside the cluster. Loops inside the AS cannot be detected by the traditional AS_path approach because the routing updates have not left the AS yet. BGP offers two extra measures for loop avoidance inside an AS when route reflectors are configured. Using an Originator ID The originator ID is a 4-byte, optional, nontransitive BGP attribute (type code 9) that is created by the route reflector. This attribute carries the router ID of the originator of the route in the local AS. If, because of poor configuration, the update comes back to the originator, the originator ignores it. Using a Cluster List The cluster list is an optional, nontransitive BGP attribute (type code 10). Each cluster is represented with a cluster ID. A cluster list is a sequence of cluster IDs that an update has traversed. When a route reflector sends a route from its clients to nonclients outside the cluster, it appends the local cluster ID to the cluster list. If the route reflector receives an update whose cluster list contains the local cluster ID, the update is ignored. This is basically the same concept as the AS_path list applied between the clusters inside the AS. Reference: http://borg.uu3.net/cisco/inter_arch/page11.html

• Question 990:

  What does the DIS on a LAN periodically transmit in multicast to ensure that the IS-IS link- state database is accurate?

  A. ISH
  B. CSNP
  C. IIH
  D. PSNP
  E. LIP
  B. CSNP