Network topologies (star, bus, ring, mesh) in Computer Networks - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Star Topology

In a star network topology, what happens if the central device fails?

A All devices lose communication because the central device controls all connections.

B The devices continue communicating directly without the central device.

C The network automatically reroutes data through other devices to maintain communication.

D Only the device connected to the failed central device loses communication.

💡 Hint

Think about the role of the central device in a star topology.

In a star topology, all devices connect through a central device like a switch or hub. If this central device fails, none of the devices can communicate because the central device manages all data traffic.

📋 Factual

intermediate

Identifying Bus Topology Characteristics

Which of the following is a key characteristic of a bus topology?

A Each device is connected to a single central cable called the bus.

B Devices are connected in a closed loop forming a ring.

C Every device is connected to every other device directly.

D Devices connect to a central hub or switch.

💡 Hint

Recall the physical layout of a bus topology.

In a bus topology, all devices share a single communication line called the bus. Data travels along this cable to all devices.

🔍 Analysis

advanced

Comparing Ring and Mesh Topologies

Which statement correctly compares ring and mesh topologies in terms of fault tolerance?

A Ring topology can continue working if one connection breaks, but mesh topology cannot.

B Mesh topology provides higher fault tolerance because devices have multiple paths to communicate.

C Both topologies fail completely if any single device fails.

D Ring topology has better fault tolerance because data travels in both directions simultaneously.

💡 Hint

Consider how many connections each device has in both topologies.

Mesh topology connects devices with multiple paths, so if one link fails, data can take another path. Ring topology relies on a single path around the ring, so a break can disrupt communication unless special mechanisms are used.

🚀 Application

advanced

Choosing a Topology for a Small Office

A small office wants a network that is easy to set up, cost-effective, and simple to troubleshoot. Which topology is the best choice?

A Mesh topology because it offers multiple paths for data.

B Bus topology because it requires a central device.

C Ring topology because it uses less cable than star.

D Star topology because it is easy to manage and troubleshoot.

💡 Hint

Think about ease of troubleshooting and setup simplicity.

Star topology is popular in small offices because each device connects to a central hub, making it easy to isolate problems and add or remove devices without affecting the whole network.

❓ Reasoning

expert

Impact of Adding Devices in Mesh Topology

In a fully connected mesh topology with 5 devices, how many direct connections exist? What happens to the number of connections if one more device is added?

A There are 5 connections with 5 devices; adding one device increases connections to 6.

B There are 20 connections with 5 devices; adding one device increases connections to 25.

C There are 10 connections with 5 devices; adding one device increases connections to 15.

D There are 15 connections with 5 devices; adding one device increases connections to 21.

💡 Hint

Use the formula for connections in a fully connected mesh: n(n-1)/2.

In a fully connected mesh, the number of connections is calculated by n(n-1)/2, where n is the number of devices. For 5 devices: 5*4/2 = 10 connections. Adding one device (6 devices): 6*5/2 = 15 connections.

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