In this post, I will discuss the CCNA ( ICND1, ICND2, and CCNA 200-120 ) exam questions related to basic Internetworking and OSI layer. To keep in mind for you who do not speak Russian or Japanese, that the CCNA exam is always in English.
And therefore you have to get used to practice CCNA practice questions also in English.

The discussion of the questions later on it is expected that you will understand some of the important topics related to basic internetworking and also OSI layer, these topics are as follows:
a.     What is the difference between broadcast domains and collision domains.
b.    Knowing and understanding what causes traffic congestion in the LAN.
c.    The difference between the MAC address and IP address.
d.    Know, understand and differentiate the types of network devices such as Hub, Switch, Bridge, and Router.
e.     Knowing and understanding what the advantages and benefits of the Router.
f.     Know and understand and be able to distinguish what is a connection-oriented and connectionless, how the role of both, connection-oriented and connectionless, in data communications between computers.
g.     Determine the layers of the OSI layer, to understand the function of each layer and explain how the network devices and protocols incorporated in or included in the layer of the OSI layer number.

Questions 1
Which of the following statements is / are true with regard to the device shown below?
(Choose all that apply.)

A. It includes one collision domain and one broadcast domain
B. It includes one 10 collision domains and broadcast domains
C. It includes 10 collision domains and one broadcast domain
D. It includes one 10 collision domains and broadcast domains
E. It includes 10 collision domains and broadcast domains 10

Answer:  A

Discussion:
In this matter are shown an image which is a symbol of one of the network device, the device is a hub. Like what the Hub characteristics:
a.  Each connection to the Hub are in a broadcast domain and the same collision domain.
b.  No matter how many hosts are connected to the hub, the hub connection there is one broadcast domain and a single collision domain.
c.  Remember that the symbol of the hub is a box, with the top there is a line with arrows at the ends.
The meaning of a line with two ends of arrows, symbolizing that the data traffic into and out of the hub only through same track.
At hub, there is no separation lane as happened on the switch and therefore in the hub there is a collision domain.

Answering question like this, not only requires knowledge of related character of the Hub but also need to know about what was broadcast and collision domains.

Question 2
With respect to the OSI model, which of the following are correct statements about PDUs?
A.  A segment contains IP addresses.
B.  A packet contains IP addresses.
C.  A segment contains MAC addresses.
D.  A packet contains MAC addresses.

Answer: B

Discussion:
At this question, that asked is any appropriate statement related to the PDU, or Protocol Data Unit, that exist in every layer of the OSI layer. At each layer there is usually a specific data format known as PDU. Each layer has a different PDU, the following is the format of the data or PDU on the three layers of the OSI layers:
1.    At layer  1, Protocol Data Unit known as bits.
2.    At layer  2, Protocol Data Unit known as Frame, Frame contains the Mac address destination and source.
3.    At Layer  3, Protocol Data Unit known as Packet, packet contains the IP address of the destination and source.
4.    At layer  4, Protocol Data Unit known as Segment.
To answer this question you should understand about the OSI layers and how the data encapsulation process occurs.

Questions 3
You are the Cisco administrator for your company. A new branch office is opening and you are selecting the Necessary hardware to support the network.
There will be two groups of computers, call now organized by the department. The Sales group of computers will be assigned IP addresses from 192.168.1.2 to 192.168.1.50 ranging.
The Accounting group will be assigned IP addresses ranging from 10.0.0.2 to 10.0.0.50. What type of device should you select to connect the two groups of computers so that data communication can occur?

A. Hub
B. Switch
C. Router
D. Bridge

Answer:  C

Discussion:
In this question, we are informed that there are two groups of computers in accordance with the existing department at the company.
The first group of computers, Sales, use the IP address 192.168.1.2 to 192.168.1.50, assuming that its default Subnet 255.255.255.0.
This means, the computer or the host, at Sales group, can only communicate with other computers using IP addresses in the range 192.168.1.2 to 192.168.1.50, a computer with an IP address outside the IP range, could not communicate with the computer group that attached to the IP 192.168.1.0.
The second group of computers that are Accounting, with the IP address 10.0.0.2 to 10.0.0.50, we assume that its Subnet is 255.255.255.0. Like the group sales, computers in Accounting group can only communicate with hosts on a range of IP address 10.0.0.2 to 10.0.0.50 only. Outside segments IP address, it cannot communicate each other.

Both the computer group, can communicate, it would require a system or a network function that allows two groups of computers that can communicate, usually in the form of a software system that integrated into a hardware device, the device known as a router.

Both the computer group can communicate each other , so it would require a system or a network function that allows two groups of computers that can communicate. A software system that integrated into a hardware device that allows two or more  groups of computers so they can communicate each other isknown as a router.

The router is a combination of hardware and software systems. Software used to support the functions of a computer network known as NOS or Network Operating System. In general, the function of a router is to connect two or more computer networks using IP addressing system.
To prepare yourself you should deepen your knowledge of the Router.

Questions  4
The most effective way to mitigate congestion on a LAN would be to ….?
A. Upgrading the network cards
B. Change the cabling to CAT 6
C. Replace the hubs with switches
D. Upgrade the CPUs in the routers

Answer:  C

Discussion:
At question 4, from 4 answer choices, it seems there is no wrong answer, but only one answer that is most suitable for the chosen. The most appropriate answer is to replace hubs with switches. Why is that? The cause of traffic congestion caused by the use of the Hub. Hub has its limitations, the speed of data traffic through the hub only up to 10 Mbps.

Thus, when the traffic or data traffic through a very large, there will be congestion. Because the lane capacity is limited, therefore the hub must be replaced with a device that has the capability and capacity bandwidth or greater speed, the device is a switch. Switch has a speed of up to 1 Gbps.

Question 5
In the work area below draw a line from the OSI model layer to its PDU.

Answer:
In the question we are asked to match the layers of the OSI layer on the left with the corresponding PDUnya that is on the right. Each layer has a different PDU, the following is the format of the data or PDU on the three layers of the OSI layers:
1.    At layer  1, Protocol Data Unit known as bits.
2.    At layer  2, Protocol Data Unit known as Frame, Frame contains the Mac address destination and source.
3.    At Layer  3, Protocol Data Unit known as Packet, packet contains the IP address of the destination and source.
4.    At layer  4, Protocol Data Unit known as Segment.
So the answer is accordance with the table below.