Cisco 351-001 Online Practice Questions and Exam Preparation

Cisco 351-001 Online Questions & Answers

• Question 61:

  What happens when an interface is configured as passive in OSPF?

  A. No OSPF neighbor ship is formed on the interface.
  B. An OSPF neighbor ship is formed with the DR, but not with the BDR.
  C. The subnet configured on the interface is not advertised to any other neighbor.
  D. OSPF hello messages are sent as unicast instead of multicast.
  A. No OSPF neighbor ship is formed on the interface.

• Question 62:

  Which type of EIGRP routes are summarized by the auto-summary command?

  A. internal routes that are learned from a peer that is outside the range of local network statements
  B. external routes that are learned from a peer that is inside the range of local network statements
  C. locally created routes that are outside the range of local network statements
  D. external routes that are learned from a peer that is outside the range of local network statements
  B. external routes that are learned from a peer that is inside the range of local network statements

  ---

  Auto-Summarization of External Routes

  EIGRP will not auto-summarize external routes unless there is a component of the same major network that is an internal route. To illustrate, let us look at Figure 15.

  

  Router Three is injecting external routes to 192.1.2.0/26 and 192.1.2.64/26 into EIGRP using the redistribute connected command, as shown in the configurations below. Router Three interface Ethernet0 ip address 192.1.2.1 255.255.255.192 ! interface Ethernet1 ip address 192.1.2.65 255.255.255.192 ! interface Ethernet2 ip address 10.1.2.1 255.255.255.0 !router eigrp 2000 redistribute connected network 10.0.0.0 default-metric 10000 1 255 1 1500 With this configuration on Router Three, the routing table on Router One shows: one# show ip route

  10.0.0.0/8 is subnetted, 2 subnets D 10.1.2.0 [90/11023872] via 10.1.50.2, 00:02:03, Serial0 C 10.1.50.0 is directly connected, Serial0 192.1.2.0/26 is subnetted, 1 subnets D EX 192.1.2.0 [170/11049472] via 10.1.50.2, 00:00:53, Serial0 D EX 192.1.2.64 [170/11049472] via 10.1.50.2, 00:00:53, Serial0 Although auto-summary normally causes Router Three to summarize the 192.1.2.0/26 and 192.1.2.64/26 routes into one major net destination (192.1.2.0/24), it does not do this because both routes are external. However, if you reconfigure the link between Routers Two and Three to 192.1.2.128/26, and add network statements for this network on Routers Two and Three, the 192.1.2.0/24 auto-summary is then generated on Router Two. Router Three interface Ethernet0 ip address 192.1.2.1 255.255.255.192 ! interface Ethernet1 ip address 192.1.2.65 255.255.255.192 ! interface Serial0 ip address 192.1.2.130 255.255.255.192 ! router eigrp 2000 network 192.1.2.0 Now Router Two generates the summary for 192.1.2.0/24: two# show ip route D 192.1.2.0/24 is a summary, 00:06:48, Null0

  And Router One shows only the summary routE. one# show ip route

  10.0.0.0/8 is subnetted, 1 subnets C 10.1.1.0 is directly connected, Serial0 D 192.1.2.0/24 [90/11023872] via 10.1.50.2, 00:00:36, Serial0

  Reference: http://www.cisco.com/c/en/us/support/docs/ip/enhanced-interior-gateway- routing-protocol-eigrp/16406-eigrp-toc.html

• Question 63:

  DRAG DROP

  Select and Place:

  

  

• Question 64:

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

  A. Split horizon is used on PE devices to prevent loops.
  B. Spanning tree is extended from CE to CE.
  C. IP is used to switch Ethernet frames between sites.
  D. PE routers dynamically associate to peers.
  E. VPLS extends a Layer 2 broadcast domain.
  A. Split horizon is used on PE devices to prevent loops.
  E. VPLS extends a Layer 2 broadcast domain.

• Question 65:

  Which statement about how a CE router is used in an MPLS VPN is true?

  A. It is located on the customer premises, where it peers and exchanges routes with the provider edge router.
  B. It is located on the provider premises, where it peers and exchanges routes with the customer edge router.
  C. It is located on the customer premises, but it is fully controlled by the provider, which provides a full routing table to the customer.
  D. It is located on the provider premises, and it routes only MPLS label traffic.
  A. It is located on the customer premises, where it peers and exchanges routes with the provider edge router.

• Question 66:

  Refer to the exhibit.

  

  Routers R1 and R2 are configured as shown, and traffic from R1 fails to reach host 209.165.201.254. Which action can you take to correct the problem?

  A. Ensure that R2 has a default route in its routing table.
  B. Change the OSPF area type on R1 and R2.
  C. Edit the router configurations so that address 209.165.201.254 is a routable address.
  D. Remove the default-information originate command from the OSPF configuration of R2.
  A. Ensure that R2 has a default route in its routing table.

  ---

  Not sure that any of these answers are correct, it appears that this configuration is valid for reaching that one specific host IP. Answer A does have a route to that host so it would not need a default route to get to it. Choice B is incorrect as the area types have nothing to do with this. C is incorrect as that IP address is routable, and D is needed so that R1 will have a default route advertised to it from R2 so that it can reach this destination.

• Question 67:

  What are the three modes of Unicast Reverse Path Forwarding?

  A. strict mode, loose mode, and VRF mode
  B. strict mode, loose mode, and broadcast mode
  C. strict mode, broadcast mode, and VRF mode
  D. broadcast mode, loose mode, and VRF mode
  A. strict mode, loose mode, and VRF mode

• Question 68:

  Refer to the exhibit.

  

  NHRP registration is failing; what might be the problem?

  A. invalid IP addressing
  B. fragmentation
  C. incorrect NHRP mapping
  D. incorrect NHRP authentication
  D. incorrect NHRP authentication

  ---

  Configuring an authentication string ensures that only routers configured with the same string can communicate using NHRP. Therefore, if the authentication scheme is to be used, the same string must be configured in all devices configured for NHRP on a fabric

  Reference: http://www.cisco.com/c/en/us/td/docs/ios/12_4/ip_addr/configuration/guide/hadnhrp.html#w p1055432

• Question 69:

  For which kind of MPLS deployment is the next-hop-self all keyword used on a BGP neighbor command?

  A. 6VPE
  B. MPLS Carrier's carrier
  C. inter-AS MPLS VPN option D
  D. inter-AS MPLS VPN option C
  E. Unified MPLS
  E. Unified MPLS

  ---

  Since the core and aggregation parts of the network are integrated and end-to-end LSPs are provided, the Unified MPLS solution is also referred to as "Seamless MPLS." New technologies or protocols are not used here, only MPLS, Label Distribution Protocol (LDP), IGP, and BGP. Since you do not want to distribute the loopback prefixes of the PE routers from one part of the network into another part, you need to carry the prefixes in BGP. The Internal Border Gateway Protocol (iBGP) is used in one network, so the next hop address of the prefixes is the loopback prefixes of the PE routers, which is not known by the IGP in the other parts of the network. This means that the next hop address cannot be used to recurse to an IGP prefix. The trick is to make the ABR routers Route Reflectors (RR) and set the next hop to self, even for the reflected iBGP prefixes. In order for this to work, a new knob is needed. Only the RRs need newer software to support this architecture. Since the RRs advertise the BGP prefixes with the next hop set to themselves, they assign a local MPLS label to the BGP prefixes. This means that in the data plane, the packets forwarded on these end-to- end LSPs have an extra MPLS label in the label stack. The RRs are in the forwarding path. There are two possible scenarios: The ABR does not set the next hop to self for the prefixes advertised (reflected by BGP) by the ABR into the aggregation part of the network. Because of this, the ABR needs to redistribute the loopback prefixes of the ABRs from the core IGP into the aggregation IGP. If this is done, there is still scalability. Only the ABR loopback prefixes (from the core) need to be advertised into the aggregation part, not the loopback prefixes from the PE routers from the remote aggregation parts. The ABR sets the next hop to self for the prefixes advertised (reflected by BGP) by the ABR into the aggregation part. Because of this, the ABR does not need to redistribute the loopback prefixes of the ABRs from the core IGP into the aggregation IGP. In both scenarios, the ABR sets the next hop to self for the prefixes advertised (reflected by BGP) by the ABR from the aggregation part of the network into the core part. If this is not done, the ABR needs to redistribute the loopback prefixes of the PEs from the aggregation IGP into the core IGP. If this is done, there is no scalability. In order to set the next hop to self for reflected iBGP routes, you must configure the neighbor x.x.x.x next-hop-self all command.

  Reference: http://www.cisco.com/c/en/us/support/docs/multiprotocol-label-switching- mpls/mpls/116127-configure-technology-00.html

• Question 70:

  Which tunnel type can be used with encryption to provide security for IPv6 over IPv4?

  A. 6RD
  B. 6to4
  C. ISATAP
  D. IPv4-compatible
  E. GRE
  E. GRE