Cisco 351-001 Online Practice Questions and Exam Preparation

Cisco 351-001 Online Questions & Answers

• Question 131:

  Which two methods do IPsec VTIs use to identify and transmit encrypted traffic through the tunnel? (Choose two)

  A. object groups
  B. ACLs
  C. dynamic routing
  D. static routing E. NAT
  C. dynamic routing
  D. static routing E. NAT

• Question 132:

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

  A. MLD is a subprotocol of ICMPv6.
  B. When a single link supports multiple interfaces, only one interface is required to send MLD messages.
  C. MLD is a subprotocol of PIMv6.
  D. When a single link supports multiple interfaces, all supported interfaces are required to send MLD messages.
  E. There are three subtypes of MLD query messages.
  F. The code section in the MLD message is set to 1 by the sender and ignored by receivers.
  A. MLD is a subprotocol of ICMPv6.
  B. When a single link supports multiple interfaces, only one interface is required to send MLD messages.

• Question 133:

  Which option describes the purpose of the no ip next-hop-self eigrp configuration line in DMVPN deployment?

  A. It allows the spoke routers to change the next hop value when sending EIGRP updates to the hub router.
  B. It enables EIGRP to dynamically assign the next hop value based on the EIGRP database.
  C. It preserves the original next hop value as learned by the spoke routers.
  D. It preserves the original next hop value as learned by the hub routers.
  E. It allows the spoke routers to change the next hop value when sending EIGRP updates to the spoke router.
  C. It preserves the original next hop value as learned by the spoke routers.

• Question 134:

  Which two methods can you use to limit the range for EIGRP queries? (Choose two.)

  A. Use an access list to deny the multicast address 224.0.0.1 outbound from select EIGRP neighbor and permit everything else.
  B. Configure route tagging for all EIGRP routes.
  C. Summarize routes at the boundary routers of the EIGRP domain.
  D. Configure unicast EIGRP on all routers in the EIGRP domain.
  E. Configure stub routers in the EIGRP domain.
  F. Use an access list to deny the multicast address 224.0.0.10 outbound from select EIGRP neighbors and permit everything else.
  C. Summarize routes at the boundary routers of the EIGRP domain.
  E. Configure stub routers in the EIGRP domain.

• Question 135:

  Which two options are reasons for TCP starvation? (Choose two.)

  A. The use of tail drop
  B. The use of WRED
  C. Mixing TCP and UDP traffic in the same traffic class
  D. The use of TCP congestion control
  C. Mixing TCP and UDP traffic in the same traffic class
  D. The use of TCP congestion control

  ---

  It is a general best practice to not mix TCP-based traffic with UDP-based traffic (especially Streaming-Video) within a single service-provider class because of the behaviors of these protocols during periods of congestion. Specifically, TCP

  transmitters throttle back flows when drops are detected. Although some UDP applications have application-level windowing, flow control, and retransmission capabilities, most UDP transmitters are completely oblivious to drops and, thus,

  never lower transmission rates because of dropping.

  When TCP flows are combined with UDP flows within a single service-provider class and the class experiences congestion, TCP flows continually lower their transmission rates, potentially giving up their bandwidth to UDP flows that are

  oblivious to drops. This effect is called TCP starvation/UDP dominance. TCP starvation/UDP dominance likely occurs if (TCP-based) Mission-Critical Data is assigned to the same service-provider class as (UDP-based) Streaming- Video and

  the class experiences sustained congestion. Even if WRED or other TCP congestion control mechanisms are enabled on the service-provider class, the same behavior would be observed because WRED (for the most part) manages

  congestion only on TCP-based flows.

  Reference:

  http://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND/Qo S-SRND-Book/VPNQoS.html

• Question 136:

  Refer to the exhibit.

  

  Router R2 is learning the 192.168.1.0/24 network from R1 via EIGRP and eBGP. R2 then redistributes EIGRP into OSPF as metric-type 2 with default metrics. Which metric of the route in the R3 routing table?

  A. 20
  B. 30
  C. 110
  D. The route is not present in the R3 routing table.
  D. The route is not present in the R3 routing table.

• Question 137:

  Which two statements about Cisco Express Forwarding are true? (Choose two.)

  A. Cisco Express Forwarding tables contain reachability information and adjacency tables contain forwarding information.
  B. Cisco Express Forwarding tables contain forwarding information and adjacency tables contain reachability information.
  C. Changing MAC header rewrite strings requires cache validation.
  D. Adjacency tables and Cisco Express Forwarding tables can be built separately.
  E. Adjacency tables and Cisco Express Forwarding tables require packet process- switching.
  A. Cisco Express Forwarding tables contain reachability information and adjacency tables contain forwarding information.
  D. Adjacency tables and Cisco Express Forwarding tables can be built separately.

  ---

  Main Components of CEF Information conventionally stored in a route cache is stored in several data structures for Cisco Express Forwarding switching. The data structures provide optimized lookup for efficient packet forwarding. The two main components of Cisco Express Forwarding operation are the forwarding information base (FIB) and the adjacency tables. The FIB is conceptually similar to a routing table or information base. A router uses this lookup table to make destination-based switching decisions during Cisco Express Forwarding operation. The FIB is updated when changes occur in the network and contains all routes known at the time. Adjacency tables maintain Layer 2 next-hop addresses for all FIB entries. This separation of the reachability information (in the Cisco Express Forwarding table) and the forwarding information (in the adjacency table), provides a number of benefits: The adjacency table can be built separately from the Cisco Express Forwarding table, allowing both to be built without any packets being process-switched. The MAC header rewrite used to forward a packet is not stored in cache entries, so changes in a MAC header rewrite string do not require validation of cache entries.

  Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipswitch_cef/configuration/15- mt/isw-cef-15-mt-book/isw-cef-overview.html

• Question 138:

  Which statement is true about LLDP?

  A. LLDP provides VTP support.
  B. LLDP does not use a multicast address to communicate.
  C. LLDP can indicate only the duplex setting of a link, and not the speed capabilities.
  D. LLDP does not support native VLAN indication.
  D. LLDP does not support native VLAN indication.

  ---

  Cisco Discovery Protocol Versus LLDP-MED TLV Comparison

  TLV Function

  LLDP TLV

  Cisco Discovery Protocol TLV

  Native VLAN support-Indicates the native VLAN

  No

  Native VLAN TLV

  Reference:

  http://www.cisco.com/en/US/technologies/tk652/tk701/technologies_white_paper0900aecd 804cd46d.html

• Question 139:

  Which term describes an EIGRP route that has feasible successors?

  A. active
  B. passive
  C. redistributed
  D. invalid
  B. passive

  ---

  A topology table entry for a destination can have one of two states. A route is considered in the Passive state when a router is not performing a route recomputation. The route is in Active state when a router is undergoing a route recomputation. If there are always feasible successors, a route never has to go into Active state and avoids a route recomputation.

  When there are no feasible successors, a route goes into Active state and a route recomputation occurs. A route recomputation commences with a router sending a query packet to all neighbors. Neighboring routers can either reply if they have feasible successors for the destination or optionally return a query indicating that they are performing a route recomputation. While in Active state, a router cannot change the next- hop neighbor it is using to forward packets. Once all replies are received for a given query, the destination can transition to Passive state and a new successor can be selected.

  Reference: http://docwiki.cisco.com/wiki/Enhanced_Interior_Gateway_Routing_Protocol

• Question 140:

  Which three elements compose a network entity title? (Choose three.)

  A. area ID
  B. domain ID
  C. system ID
  D. NSAP selector
  E. MAC address
  F. IP address
  A. area ID
  C. system ID
  D. NSAP selector

  ---

  An IS (Intermediate system) is identified by an address known as a network access point (NASAP). The NSAP is divided up into three parts as specified by ISO/AI 10589:

  Area address -- This field is of variable length, composed of high order octets, and it excludes the System ID and N-selector (NSEL) fields. This area address is associated wit a single area within the routing domain.

  System ID -- This field is 6 octets long and should be set to a unique value with Level 1 and Level 2. The system IS defines an end system (ES) or an IS in an area. You configure the area address and the system ID with the NET command.

  You can display the system ID with the show isis topology command. NSEL -- This field is called the N-selector, also referred to as the NSAP, and it specifies the upper-layer protocol. The NSEL is the last byte of the NSAP and identifies a

  network service user. A network service user is a transport entity or the IS network entity itself. When the N-selector is set to zero, the entire NSAP is called a network entity title (NET). A NET is an NSAP where the last byte is always the n

  selector and is always zero. A NET can be from 8 to 20 bytes in length.

  Reference: http://www.cisco.com/c/en/us/td/docs/ios/iproute_isis/command/reference/irs_book/irs_is2. html