Cisco 100-101 Online Practice Questions and Exam Preparation

Cisco 100-101 Online Questions & Answers

• Question 161:

  Two routers named Atlanta and Brevard are connected by their serial interfaces as shown in the exhibit, but there is no data connectivity between them. The Atlanta router is known to have a correct configuration.

  

  Given the partial configurations shown in the exhibit, what is the problem on the Brevard router that is causing the lack of connectivity?

  A. A loopback is not set.
  B. The IP address is incorrect.
  C. The subnet mask is incorrect.
  D. The serial line encapsulations are incompatible.
  E. The maximum transmission unit (MTU) size is too large.
  F. The bandwidth setting is incompatible with the connected interface.
  B. The IP address is incorrect.

• Question 162:

  Select and Place:

  Select and Place:

  

  

• Question 163:

  Refer to the exhibit.

  

  The enterprise has decided to use the network address 172.16.0.0. The network administrator needs to design a classful addressing scheme to accommodate the three subnets, with 30, 40, and 50 hosts, as shown. What subnet mask would accommodate this network?

  A. 255.255.255.192
  B. 255.255.255.224
  C. 255.255.255.240
  D. 255.255.255.248
  E. 255.255.255.252
  A. 255.255.255.192

  ---

  Subnet mask A i.e. 255.255.255.192 with CIDR of /26 which means 64 hosts per subnet which are sufficient to accommodate even the largest subnet of 50 hosts.

  

• Question 164:

  What command sequence will configure a router to run OSPF and add network 10.1.1.0 /24 to area 0?

  A. router ospf area 0 network 10.1.1.0 255.255.255.0 area 0
  B. router ospf network 10.1.1.0 0.0.0.255
  C. router ospf 1 network 10.1.1.0 0.0.0.255 area 0
  D. router ospf area 0 network 10.1.1.0 0.0.0.255 area 0
  E. router ospf network 10.1.1.0 255.255.255.0 area 0
  F. router ospf 1 network 10.1.1.0 0.0.0.255
  C. router ospf 1 network 10.1.1.0 0.0.0.255 area 0

• Question 165:

  Refer to the exhibit.

  

  Why was this message received?

  A. No VTY password has been set.
  B. No enable password has been set.
  C. No console password has been set.
  D. No enable secret password has been set.
  E. The login command has not been set on CON 0
  F. The login command has not been set on the VTY ports.
  A. No VTY password has been set.

• Question 166:

  To allow or prevent load balancing to network 172.16.3.0/24, which of the following commands could be used in R2? (Choose two.)

  

  A. R2(config-if)#clock rate
  B. R2(config-if)#bandwidth
  C. R2(config-if)#ip ospf cost
  D. R2(config-if)#ip ospf priority
  E. R2(config-router)#distance ospf
  B. R2(config-if)#bandwidth
  C. R2(config-if)#ip ospf cost

  ---

  http://www.cisco.com/en/US/tech/tk365/technologies_white_paper09186a0080094e9e.shtml#t6

  The cost (also called metric) of an interface in OSPF is an indication of the overhead required to send packets across a certain interface. The cost of an interface is inversely proportional to the bandwidth of that interface. A higher bandwidth

  indicates a lower cost. There is more overhead (higher cost) and time delays involved in crossing a 56k serial line than crossing a 10M Ethernet line. The formula used to calculate the cost is:

  Cost = 10000 0000/bandwidth in bps

  For example, it will cost 10 EXP8/10 EXP7 = 10 to cross a 10M Ethernet line and will cost 10 EXP8/1544000 =64 to cross a T1 line.

  By default, the cost of an interface is calculated based on the bandwidth; you can force the cost of an interface with the ip ospf cost interface subconfiguration mode command.

• Question 167:

  If a host experiences intermittent issues that relate to congestion within a network while remaining connected, what could cause congestion on this LAN?

  A. half-duplex operation
  B. broadcast storms
  C. network segmentation
  D. multicasting
  B. broadcast storms

  ---

  A broadcast storm can consume sufficient network resources so as to render the network unable to transport normal traffic.

• Question 168:

  Refer to the exhibit.

  

  Assume that all router interfaces are operational and correctly configured. In addition, assume that OSPF has been correctly configured on router R2. How will the default route configured on R1 affect the operation of R2?

  A. Any packet destined for a network that is not directly connected to router R2 will be dropped immediately.
  B. Any packet destined for a network that is not referenced in the routing table of router R2 will be directed to R1. R1 will then send that packet back to R2 and a routing loop will occur.
  C. Any packet destined for a network that is not directly connected to router R1 will be dropped.
  D. The networks directly connected to router R2 will not be able to communicate with the 172.16.100.0, 172.16.100.128, and 172.16.100.64 subnetworks.
  E. Any packet destined for a network that is not directly connected to router R2 will be dropped immediately because of the lack of a gateway on R1.
  B. Any packet destined for a network that is not referenced in the routing table of router R2 will be directed to R1. R1 will then send that packet back to R2 and a routing loop will occur.

  ---

  First, notice that the more-specific routes will always be favored over less-specific routes regardless of the administrative distance set for a protocol. In this case, because we use OSPF for three networks (172.16.100.0 0.0.0.3, 172.16.100.64 0.0.0.63, 172.16.100.128 0.0.0.31) so the packets destined for these networks will not be affected by the default route. The default route configured on R1 "ip route 0.0.0.0 0.0.0.0 serial0/0 will send any packet whose destination network is not referenced in the routing table of router R1 to R2, it doesn't drop anything. These routes are declared in R1 and the question says that "OSPF has been correctly configured on router R2, so network directly connected to router R2 can communicate with those three subnetworks. As said above, the default route configured on R1 will send any packet destined for a network that is not referenced in its routing table to R2; R2 in turn sends it to R1 because it is the only way and a routing loop will occur.

• Question 169:

  What are two benefits of using a single OSPF area network design? (Choose two.)

  A. It is less CPU intensive for routers in the single area.
  B. It reduces the types of LSAs that are generated.
  C. It removes the need for virtual links.
  D. It increases LSA response times.
  E. It reduces the number of required OSPF neighbor adjacencies.
  B. It reduces the types of LSAs that are generated.
  C. It removes the need for virtual links.

• Question 170:

  Refer to the exhibit.

  

  After configuring two interfaces on the HQ router, the network administrator notices an error message. What must be done to fix this error?

  A. The serial interface must be configured first.
  B. The serial interface must use the address 192.168.1.2
  C. The subnet mask of the serial interface should be changed to 255.255.255.0
  D. The subnet mask of the FastEthernet interface should be changed to 255.255.255.240
  E. The address of the FastEthernet interface should be changed to 192.168.1.66
  D. The subnet mask of the FastEthernet interface should be changed to 255.255.255.240