Ccna certification Practice Tests

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Appendix 

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  Answers to Practice Test Questions

 9.  C.  Platform as a Service (PaaS) is commonly used by software developers. It provides 

a development platform that the software developer can use to create applications. An 

example of this is a web server with PHP and MySQL, which is hosted in the cloud. 

Software as a Service (SAAS) is a software product similar to email or social networking 

software in which you use the software provided as a service. Infrastructure as a Service 

(IaaS) allows you to rent infrastructure such as virtual machines (VMs), virtual networks, 

or even DNS, just to name a few. Disaster Recovery as a Service (DRaaS) is another popular 

service; you can rent storage and compute power to facilitate a disaster recovery site.

 10.  D.  Rapid elasticity is the ability to add and remove compute capability in the cloud. As 

demand increases, compute power can be increased by adding more CPUs or servers. 

As demand for compute power decreases, CPUs or servers can be removed. Resource 

pooling is the concept that all of the physical hosts the provider has are pooled together 

to provide a customer with resources. Measured services is the concept that the provider 

can determine the amount of computing, network, or storage a customer has used so that 

they can be billed or a report can be created. Broad network access is the concept that the 

resources can be accessed from anywhere on the Internet.

 11.  B.  During the three-way-handshake, Computer A sends a SYN flag along with its 

receiving window size and initial sequence number. Then Computer B sends a SYN flag 

and ACK flag along with its receiving window and acknowledgment of the sequence 

number. Finally, Computer A sends an ACK flag, which acknowledges the synchronization 

of Computer B’s receiving window. Communication begins and is considered to be in an 

established state. All of the other options are incorrect.

 12.  D.  The summary route of 172.16.32.0/21 contains 172.16.38.0/24 as a valid network 

route. The /21 CIDR mask defines networks in multiples of 8 in the third octet of the 

network address. Therefore, the next summary network address is 172.16.40.0/21. All of 

the other options are incorrect.

 13.  D.  The IP address 225.34.5.4 is a multicast IP address. Multicast IP addresses are defined 

as Class D addresses in the range 224.0.0.1 to 239.255.255.254. Class A defines any 

address with the first octet of 0 to 127. Class B defines any address with the first octet of 

128 to 191. Class C defines any address with the first octet of 192 to 223.

 14.  B.  Stateful DHCPv6 uses a process similar to DORA for IPv4. However, IPv6 uses 

multicast in lieu of broadcasts via the DHCPv6 Solicit multicast address. The Discover, 

Offer, Request, and Acknowledge (DORA) process only happens with IPv4 via 

broadcasts. Neighbor Solicitation (NS) and Neighbor Advertisement (NA) messages are 

used with the Neighbor Discovery Protocol (NDP). Router Solicitation (RS) and Router 

Advertisement (RA) messages are used with Stateless Autoconfiguration (SLAAC).

 15.  C.  Before a host can communicate via an RS packet, it first needs a valid IP address. The 

first address is a link-local address so that it can send an RS packet and receive an RA 

packet. The client performs Duplicate Address Detection (DAD) on the link-local address. 

Then a Router Solicitation (RS) message is sent from the client. A Router Advertisement 

(RA) message is sent from the router to the client with the network ID. The host portion 

is then configured and DAD is checked again to make sure that the host does not have a 

duplicate IP address.

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Chapter 8: Practice Exam 2