Cisco 351-001 Online Practice Questions and Exam Preparation

Cisco 351-001 Online Questions & Answers

• Question 391:

  Refer to the exhibit.

  

  Which two options are effects of the given configuration? (Choose two.)

  A. It sets the data export destination to 209.165.200.227 on UDP port 49152.
  B. It enables Cisco Express Forwarding on interface FastEthernet0/0.
  C. It configures the export process to include the BGP peer AS of the router gathering the data.
  D. It enables NetFlow switching on interface FastEthernet0/0.
  E. It sets the data export destination to 209.165.200.227 on TCP port 49152.
  A. It sets the data export destination to 209.165.200.227 on UDP port 49152.
  D. It enables NetFlow switching on interface FastEthernet0/0.

  ---

  The "ip flow-export destination 209.165.200.227 49152" command specifies that the data export destination server is 209.165.200.227 using UDP port 49152. The "ip route-cache flow" command under the fastethernet 0/0 interface enable netflow switching on that interface.

• Question 392:

  What is the hop limit for an MLD message?

  A. 1
  B. 2
  C. 15
  D. 255
  A. 1

  ---

  MLD uses the Internet Control Message Protocol (ICMP) to carry its messages. All MLD messages are link-local with a hop limit of 1, and they all have the alert option set. The alert option implies an implementation of the hop-by-hop option header.

  Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipmulti_lsm/configuration/xe- 3s/imc-lsm-xe-3s-book/ipv6-mcast-mld-xe.html

• Question 393:

  Which two statements about 6PE are true? (choose two)

  A. iBGP peering between the PE routers should be done using an IPv6 address.
  B. It does not require MPLS between the PE routers.
  C. It requires a VRF on the IPv6 interface
  D. It requires BGP to exchange labeled IPv6 unicast between PE routers
  E. Uses an IPv4-mapped IPv6 address as the IPv4 next-hop on PE router
  D. It requires BGP to exchange labeled IPv6 unicast between PE routers
  E. Uses an IPv4-mapped IPv6 address as the IPv4 next-hop on PE router

• Question 394:

  What are three required commands when you enable source-specific multicast for addresses in the range 233.0.0.0/8? (Choose three.)

  A. ip multicast-routing
  B. ip igmp version 3
  C. ip pim ssm-range 233.0.0.0/8
  D. ip igmp version 2
  E. ip pim ssm-range default
  F. set routing-options multicast ssm-groups 233.0.0.0/8
  A. ip multicast-routing
  B. ip igmp version 3
  C. ip pim ssm-range 233.0.0.0/8

• Question 395:

  Which two options are the two underlying protocols on which a DMVPN relies? (Choose two.)

  A. IPsec
  B. NHRP
  C. GDOI
  D. ISAKMP
  E. SSL
  F. NLRI
  A. IPsec
  B. NHRP

• Question 396:

  Refer to the exhibit.

  

  Which two statements are true about the displayed STP state? (Choose two.)

  A. The STP version configured on the switch is IEEE 802.1w.
  B. Port-channel 1 is flapping and the last flap occurred 1 minute and 17 seconds ago.
  C. The switch does not have PortFast configured on Gi0/15.
  D. BPDUs with the TCN bit set are transmitted over port channel 1.
  C. The switch does not have PortFast configured on Gi0/15.
  D. BPDUs with the TCN bit set are transmitted over port channel 1.

  ---

  A port enabled with portfast will not send topology changes when a port goes up or down, but here we see that 296 TCN's were sent so we know that Gi 0/15 does not have portfast enabled. TCN's are sent using BPDU's over the root port, which we see is port channel 1.

• Question 397:

  Which three features are considered part of the IPv6 first-hop security suite? (Choose three.)

  A. DNS guard
  B. destination guard
  C. DHCP guard
  D. ICMP guard
  E. RA guard
  F. DoS guard
  B. destination guard
  C. DHCP guard
  E. RA guard

  ---

  Cisco IOS has (at least) these IPv6 first-hop security features: IPv6 RA Guard rejects fake RA messages coming from host (non-router) ports (not sure whether it handles all possible IPv6 header fragmentation attacks). Interestingly, it can also validate the contents of RA messages (configuration flags, list of prefixes) received through router-facing ports, potentially giving you a safeguard against an attack of fat fingers. DHCPv6 Guard blocks DHCPv6 messages coming from unauthorized DHCPv6 servers and relays. Like IPv6 RA Guard it also validates the DHCPv6 replies coming from authorized DHCPv6 servers, potentially providing protection against DHCPv6 server misconfiguration. IPv6 Snooping and device tracking builds a IPv6 First-Hop Security Binding Table (nicer name for ND table) by monitoring DHCPv6 and ND messages as well as regular IPv6 traffic. The binding table can be used to stop ND spoofing (in IPv4 world we'd call this feature DHCP Snooping and Dynamic ARP Inspection). IPv6 Source Guard uses the IPv6 First-Hop Security Binding Table to drop traffic from unknown sources or bogus IPv6 addresses not in the binding table. The switch also tries to recover from lost address information, querying DHCPv6 server or using IPv6 neighbor discovery to verify the source IPv6 address after dropping the offending packet(s). IPv6 Prefix Guard is denies illegal off-subnet traffic. It uses information gleaned from RA messages and IA_PD option of DHCPv6 replies (delegated prefixes) to build the table of valid prefixes. IPv6 Destination Guard drops IPv6 traffic sent to directly connected destination addresses not in IPv6 First-Hop Security Binding Table, effectively stopping ND exhaustion attacks. Reference: http://blog.ipspace.net/2013/07/first-hop-ipv6-security-features-in.html

• Question 398:

  Which two statements about OSPFv3 are true? (Choose two.)

  A. It supports unicast address families for IPv4 and IPv6.
  B. It supports unicast address families for IPv6 only.
  C. It supports only one address family per instance.
  D. It supports the use of a cluster ID for loop prevention.
  E. It supports multicast address families for IPv4 and IPv6.
  F. It supports multicast address families for IPv6 only.
  A. It supports unicast address families for IPv4 and IPv6.
  C. It supports only one address family per instance.

• Question 399:

  Which statement is true about IGMP?

  A. Multicast sources send IGMP messages to their first-hop router, which then generates a PIM join message that is then sent to the RP.
  B. Multicast receivers send IGMP messages to their first-hop router, which then forwards the IGMP messages to the RP.
  C. IGMP messages are encapsulated in PIM register messages and sent to the RP.
  D. Multicast receivers send IGMP messages to signal their interest to receive traffic for specific multicast groups.
  D. Multicast receivers send IGMP messages to signal their interest to receive traffic for specific multicast groups.

  ---

  

  In the example shown above, the receivers (the designated multicast group) are interested in receiving the video data stream from the source. The receivers indicate their interest by sending an Internet Group Management Protocol (IGMP)

  host report to the routers in the network. The routers are then responsible for delivering the data from the source to the receivers.

  Reference:

  http://www.cisco.com/c/en/us/td/docs/ios/solutions_docs/ip_multicast/White_papers/mcst_o vr.html

• Question 400:

  Which Layer 2 tunneling technique eliminates the need for pseudowires?

  A. OTV
  B. L2TPv3
  C. AToM
  D. VPLS
  A. OTV