Switching and bridging in Computer Networks - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

How does a network switch learn device locations?

In a local area network, how does a switch know which device is connected to which port?

A It uses a MAC address table built by observing source addresses of incoming frames.

B It assigns IP addresses to devices and maps them to ports.

C It broadcasts all incoming frames to every port to find the device.

D It uses DNS to resolve device names to ports.

💡 Hint

Think about how switches learn from the traffic they receive.

Switches build a MAC address table by looking at the source MAC address of each frame they receive and associating it with the port it came from. This helps them forward frames only to the correct port.

📋 Factual

intermediate

What is the main purpose of a network bridge?

What does a network bridge do in a LAN?

A It assigns IP addresses to devices on the network.

B It connects two or more network segments and filters traffic based on MAC addresses.

C It converts digital signals to analog signals for transmission.

D It encrypts data to secure communication between devices.

💡 Hint

Think about how bridges help reduce traffic between network parts.

A bridge connects separate network segments and uses MAC addresses to decide whether to forward or block traffic, reducing unnecessary data on each segment.

🔍 Analysis

advanced

Why might a switch cause a broadcast storm in a network?

Consider a network with multiple switches connected in a loop without any special protocol. What problem can occur and why?

A Broadcast frames can circulate endlessly causing a broadcast storm because loops create multiple paths without control.

B Broadcast storms happen only if devices have duplicate IP addresses, unrelated to switches.

C Switches will automatically convert broadcast frames to unicast frames to avoid storms.

D Switches will block all traffic to prevent loops, causing network downtime.

💡 Hint

Think about what happens when frames keep circulating without a stop.

Without protocols like Spanning Tree Protocol, loops cause broadcast frames to be forwarded repeatedly, flooding the network and causing a broadcast storm.

❓ Comparison

advanced

Difference between a switch and a hub in handling traffic

How does a switch differ from a hub when forwarding data in a network?

A Both switch and hub forward data only to the destination port but use different speeds.

B A switch broadcasts data to all ports, while a hub forwards data only to the destination port.

C Both switch and hub broadcast data to all ports but switches encrypt the data.

D A switch forwards data only to the destination port, while a hub broadcasts data to all ports.

💡 Hint

Consider how each device treats incoming data frames.

A switch uses its MAC address table to send data only to the correct port, reducing unnecessary traffic. A hub simply sends data to all ports, causing more collisions and traffic.

❓ Reasoning

expert

How does Spanning Tree Protocol (STP) prevent network loops?

In a network with multiple switches connected in loops, how does STP prevent broadcast storms?

A STP encrypts broadcast frames to prevent them from looping.

B STP increases the speed of all ports to handle loops efficiently.

C STP detects loops and blocks some switch ports to create a loop-free logical topology.

D STP assigns unique IP addresses to each switch to avoid loops.

💡 Hint

Think about how STP controls which paths are active.

STP works by detecting loops and disabling some switch ports temporarily, so the network forms a tree structure without loops, preventing broadcast storms.