N10-007: CompTIA Network+ Exam | Collision Domains Calculation

How Many Collision Domains Exist in an Office Network?

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Question

An office network consists of one two-port router connected to a 12-port switch.

A four-port hub is also connected to the switch.

On this particular network, which of the following is the number of collision domains that exist?

A.

3 B.

12 C.

13 D.

14 E.

15

D.

Explanations

An office network consists of one two-port router connected to a 12-port switch.

A four-port hub is also connected to the switch.

On this particular network, which of the following is the number of collision domains that exist?

A.

3

B.

12

C.

13

D.

14

E.

15

D.

In computer networking, a collision domain refers to a network segment where data packets can collide with one another when two or more devices attempt to transmit data at the same time. When a collision occurs, the data packets are discarded, and the devices must retransmit their data, causing delays and reducing network efficiency.

In this scenario, there are two devices connected to the router, which means that there is only one collision domain between them. The 12-port switch creates 12 separate collision domains, one for each of its ports. This is because each port on a switch creates its own separate collision domain, where data can flow freely without colliding with other packets.

The four-port hub connected to the switch, however, creates only one collision domain, as all data transmitted through the hub will collide with each other. This is because hubs operate at the physical layer of the OSI model, where all data is broadcast to all connected devices on the same network segment.

Therefore, the total number of collision domains in this network is 1 (between the two devices connected to the router) + 12 (one for each port on the switch) + 1 (due to the hub) = 14.

So, the correct answer is D. 14.