Cisco 351-001 Online Practice Questions and Exam Preparation

Cisco 351-001 Online Questions & Answers

• Question 571:

  Refer to the exhibit.

  

  Which statement is true about a VPNv4 prefix that is present in the routing table of vrf one and is advertised from this router?

  A. The prefix is advertised only with route target 100:1.
  B. The prefix is advertised with route targets 100:1 and 100:2.
  C. The prefix is advertised only with route target 100:3.
  D. The prefix is not advertised.
  E. The prefix is advertised with route targets 100:1, 100:2, and 100:3.
  A. The prefix is advertised only with route target 100:1.

  ---

  The route target used for prefix advertisements to other routers is defined on the route- target export command, which shows 100:1 in this case for VPNv4 routes.

• Question 572:

  

  NO: 82

  Refer to the exhibit.

  Which three statements about the R1 configuration are true? (Choose three.)

  A. The virtual circuit identifier is 1611 and the virtual circuit is down.
  B. The local label for the circuit is 4006.
  C. The targeted LDP session to the remote peer is up.
  D. The local label for the circuit is 1611.
  E. The virtual circuit identifier is 4006 and the virtual circuit is down.
  F. The circuit is using MPLS VC type 4.
  A. The virtual circuit identifier is 1611 and the virtual circuit is down.
  B. The local label for the circuit is 4006.
  C. The targeted LDP session to the remote peer is up.

  ---

  The number after the vc is the identifier, which is 1611 in this case. Here, the VC status is shown as down. As shown, the MPLS VC labels: local 4006, remote unassigned shows the local label used is 4006. The targeted LDP session is up as verified by the "Signalling protocol: LDP, peer 172.16.12.70 up" statement in the output.

• Question 573:

  A company is multihomed to several Internet providers using EBGP. Which two measures guarantee that the network of the company does not become a transit AS for Internet traffic? (Choose two.)

  A. Prepend three times the AS number of the company to the AS path list.
  B. Add the community NO_EXPORT when sending updates to EBGP neighbors.
  C. Write AS-path access-list which permits one AS long paths only and use it to filter updates sent to EBGP neighbors.
  D. Add the community NO_EXPORT when receiving updates from EBGP neighbors.
  C. Write AS-path access-list which permits one AS long paths only and use it to filter updates sent to EBGP neighbors.
  D. Add the community NO_EXPORT when receiving updates from EBGP neighbors.

  ---

  By default BGP will advertise all prefixes to EBGP (External BGP) neighbors. This means that if you are multi-homed (connected to two or more ISPs) that you might become a transit AS. Let me show you an example:

  

  R1 is connected to ISP1 and ISP2 and each router is in a different AS (Autonomous System). Since R1 is multi-homed it's possible that the ISPs will use R1 to reach each other. In order to prevent this we'll have to ensure that R1 only

  advertises prefixes from its own autonomous system.

  As far as I know there are 4 methods how you can prevent becoming a transit AS:

  Filter-list with AS PATH access-list.

  No-Export Community.

  Prefix-list Filtering

  Distribute-list Filtering

  Reference: http://networklessons.com/bgp/bgp-prevent-transit-as/

• Question 574:

  Which two statements about the protected ports feature and the private VLAN feature are true? (Choose two.)

  A. The protected ports feature is limited to the local switch.
  B. The protected ports feature can isolate traffic between two "protected" ports on different switches.
  C. The private VLAN feature is limited to the local switch.
  D. The private VLAN feature prevents interhost communication within a VLAN across one or more switches.
  A. The protected ports feature is limited to the local switch.
  D. The private VLAN feature prevents interhost communication within a VLAN across one or more switches.

  ---

  Protected Ports (PVLAN Edge)

  In some network environments, there is a requirement for no traffic to be seen or forwarded between host(s) on the same LAN segment, thereby preventing interhost communications. The PVLAN edge feature provisions this isolation by

  creating a firewall-like barrier, thereby blocking any unicast, broadcast, or multicast traffic among the protected ports on the switch. Note that the significance of the protected port feature is limited to the local switch, and there is no provision in

  the PVLAN edge feature to isolate traffic between two "protected" ports located on different switches. For this purpose, the PVLAN feature can be used.

  Reference: http://www.ciscopress.com/articles/article.asp?p=1181682andseqNum=2

• Question 575:

  Which two services are used to transport Layer 2 frames across a packet-switched network? (Choose two.)

  A. Frame Relay
  B. ATM
  C. AToM
  D. L2TPv3
  C. AToM
  D. L2TPv3

  ---

  Both AToM and L2TPv3 have the common objective of transmitting packet switched traffic of L2 frames (Frame Relay, ATM, and Ethernet) across a packet- switched network. Reference: Layer 2 VPN Architectures - Google Books Result Wei Luo, Carlos Pignataro, Anthony Chan https://books.google.com/books?isbn=0132796864

• Question 576:

  Which two fields reside in the initial CHAP challenge packet? (Choose two.)

  A. the authentication name of the challenger
  B. a random hash value generated by the device
  C. the hashed packet type ID
  D. the packet type ID in clear text
  A. the authentication name of the challenger
  D. the packet type ID in clear text

  ---

  When a caller A dials in to an access server B, The Access server sends across the link an initial Type 1 authentication packet called a Challenge. This Challenge packet contains a randomly generated number, an ID sequence number to identify the challenge (sent in clear text) and the authentication name of the challenger.

  Reference: http://www.rhyshaden.com/ppp.htm

• Question 577:

  Which two are features of DMVPN? (Choose two.)

  A. It does not support spoke routers behind dynamic NAT.
  B. It requires IPsec encryption.
  C. It only supports remote peers with statically assigned addresses.
  D. It supports multicast traffic.
  E. It offers configuration reduction.
  D. It supports multicast traffic.
  E. It offers configuration reduction.

  ---

  DMVPN Hub-and-spoke deployment model: In this traditional topology, remote sites (spokes) are aggregated into a headend VPN device at the corporate headquarters (hub). Traffic from any remote site to other remote sites would need to pass through the headend device. Cisco DMVPN supports dynamic routing, QoS, and IP Multicast while significantly reducing the configuration effort.

  Reference: http://www.cisco.com/c/en/us/products/collateral/security/dynamic-multipoint- vpn-dmvpn/data_sheet_c78-468520.html

• Question 578:

  Which three statements about dot1Q trunking are true? (Choose three)

  A. A trunk port can be a tunnel port.
  B. The default switchport mode is dynamic desirable.
  C. A trunk port can be a secure port.
  D. Trunk ports negotiate encapsulation by default.
  E. Enabling 802.1x on a trunk port results in an error.
  F. The default switchport mode is dynamic auto.
  A. A trunk port can be a tunnel port.
  E. Enabling 802.1x on a trunk port results in an error.
  F. The default switchport mode is dynamic auto.

• Question 579:

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

  A. RIP, IGRP, and EIGRP can automatically summarize routing information at network address boundaries.
  B. EIGRP can automatically summarize external routes.
  C. The area range command can aggregate addresses on the ASBR.
  D. The summary-address command under the router process configures manual summarization on RIPv2 devices.
  E. The ip classless command enables classful protocols to select a default route to an unknown subnet on a network with other known subnets.
  A. RIP, IGRP, and EIGRP can automatically summarize routing information at network address boundaries.
  E. The ip classless command enables classful protocols to select a default route to an unknown subnet on a network with other known subnets.

• Question 580:

  Which two statements about static route configuration are true? (Choose two)

  A. They add to the number of routes in the routing table.
  B. The distance command modifies the administrative distance
  C. The redistribute static command will redistribute classful networks into OSPF.
  D. They add significant overhead to the router CPU.
  E. The ip route static bfd command is used for BFD peer discovery.
  F. The permanent key word allows the route to remain in the route table if the interface goes down.
  C. The redistribute static command will redistribute classful networks into OSPF.
  F. The permanent key word allows the route to remain in the route table if the interface goes down.