Network topologies (star, bus, ring, mesh) in Computer Networks - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a star topology in networking?

A star topology connects all devices to a central device called a hub or switch. Each device has its own cable to the center, making it easy to manage and isolate problems.

beginner

How does a bus topology work?

In a bus topology, all devices share a single communication line or cable. Data travels in both directions, and each device listens for data addressed to it.

beginner

Describe the ring topology.

A ring topology connects devices in a circular way. Data travels around the ring in one direction, passing through each device until it reaches the destination.

intermediate

What is a mesh topology and its main advantage?

A mesh topology connects every device to every other device directly. This provides high reliability because if one connection fails, data can take another path.

beginner

Which topology is easiest to troubleshoot and why?

Star topology is easiest to troubleshoot because each device connects to a central point. If one device or cable fails, it does not affect others, making problems easier to find.

In which topology do all devices share a single communication line?

A Bus topology

B Star topology

C Ring topology

D Mesh topology

In bus topology, all devices connect to one main cable and share it for communication.

Which topology forms a closed loop where data travels in one direction?

A Star

B Bus

C Ring

D Mesh

Ring topology connects devices in a circle, and data moves around the ring in one direction.

What is the main benefit of mesh topology?

A Single cable for all devices

B Simple wiring

C Uses a central hub

D High reliability through multiple paths

Mesh topology connects devices directly to many others, so if one link fails, data can use another path.

Which topology is most vulnerable to a single cable failure affecting the entire network?

A Star

B Bus

C Mesh

D None

In bus topology, if the main cable breaks, the whole network can fail.

In star topology, what device usually connects all other devices?

A Switch or hub

B Modem

C Repeater

D Router

A switch or hub acts as the central point connecting all devices in a star topology.

Explain the differences between star, bus, ring, and mesh network topologies.

Think about how devices connect and how data travels in each topology.

Describe a real-life situation where a mesh topology would be better than a bus topology.

Consider situations where network failure is not an option.

Practice

1. Which network topology connects all devices to a single central device like a switch or hub?

easy

A. Bus topology

B. Star topology

C. Ring topology

D. Mesh topology

Solution

1. Step 1: Understand the central device concept

   Star topology connects all devices to one central device, which manages communication.

2. Step 2: Compare with other topologies

   Bus uses a single cable, ring connects devices in a circle, mesh connects devices directly to many others.

3. Final Answer:

   Star topology -> Option B

4. Quick Check:

   Central device = Star topology [OK]

Hint: Central device means star topology [OK]

Common Mistakes:

• Confusing bus with star because both use cables
• Thinking ring has a central device
• Mixing mesh with star due to multiple connections

2. Which of the following is the correct description of a bus topology?

easy

A. Devices connected in a closed loop

B. Devices connected to a central hub

C. All devices connected to a single cable

D. Each device connected to every other device

Solution

1. Step 1: Recall bus topology structure

   Bus topology connects all devices along a single communication cable.

2. Step 2: Eliminate other options

   Closed loop is ring, every device connected is mesh, central hub is star.

3. Final Answer:

   All devices connected to a single cable -> Option C

4. Quick Check:

   Single cable = Bus topology [OK]

Hint: Bus means one main cable for all devices [OK]

Common Mistakes:

• Confusing ring (closed loop) with bus
• Thinking mesh is a single cable
• Mixing star's central hub with bus

3. In a ring topology with 5 devices, if one device fails, what happens to the network communication?

medium

A. Communication switches to a central hub

B. Only the failed device loses connection

C. Communication continues normally

D. The entire network communication is disrupted

Solution

1. Step 1: Understand ring topology communication

   Devices are connected in a closed loop; data passes through each device.

2. Step 2: Analyze failure impact

   If one device fails, the loop breaks, stopping communication for all devices.

3. Final Answer:

   The entire network communication is disrupted -> Option D

4. Quick Check:

   One failure breaks ring loop = disruption [OK]

Hint: Ring breaks if one device fails [OK]

Common Mistakes:

• Assuming only failed device loses connection
• Thinking ring has a backup path like mesh
• Confusing with star topology behavior

4. A network uses a mesh topology but experiences frequent data collisions. What is the most likely cause?

medium

A. There is no central device to control traffic

B. Devices are connected in a ring causing loops

C. Devices are connected in a single cable

D. Only one device is connected to the network

Solution

1. Step 1: Understand mesh topology traffic

   Mesh connects devices directly; without control, many devices send data simultaneously.

2. Step 2: Identify cause of collisions

   Without a central controller or protocol, data packets collide causing errors.

3. Final Answer:

   There is no central device to control traffic -> Option A

4. Quick Check:

   No traffic control = collisions in mesh [OK]

Hint: No controller causes collisions in mesh [OK]

Common Mistakes:

• Confusing mesh with bus single cable
• Thinking ring causes collisions here
• Assuming one device can't cause collisions

5. A company wants a network where each device connects to every other device directly for maximum reliability. Which topology should they choose and why?

hard

A. Mesh, because every device connects directly to all others

B. Star, because it uses a central hub for easy management

C. Bus, because it uses a single cable to connect all devices

D. Ring, because devices form a closed loop for data flow

Solution

1. Step 1: Identify topology with direct device-to-device connections

   Mesh topology connects every device directly to all others, ensuring reliability.

2. Step 2: Compare other topologies for reliability

   Star depends on central hub, bus uses one cable, ring forms a loop but not all direct connections.

3. Final Answer:

   Mesh, because every device connects directly to all others -> Option A

4. Quick Check:

   Direct connections = Mesh topology [OK]

Hint: Direct all-to-all connections mean mesh [OK]

Common Mistakes:

• Choosing star for reliability ignoring central point failure
• Thinking bus provides direct connections
• Confusing ring loop with full direct connections