Socket programming basics in Computer Networks - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

What is the primary purpose of a socket in network programming?

Choose the best description of what a socket does in computer networks.

A It stores large amounts of data temporarily during network communication.

B It encrypts data before sending it over the internet to ensure security.

C It manages the physical connection cables between computers.

D It acts as an endpoint for sending and receiving data between two machines over a network.

💡 Hint

Think about how two programs communicate over a network.

A socket is like a door or endpoint that allows two computers to send and receive data. It does not handle encryption, storage, or physical cables directly.

📋 Factual

intermediate

Which protocol is commonly used with sockets for reliable communication?

Identify the protocol that ensures data is delivered reliably and in order when using sockets.

A IP (Internet Protocol)

B TCP (Transmission Control Protocol)

C UDP (User Datagram Protocol)

D FTP (File Transfer Protocol)

💡 Hint

Consider which protocol manages connection and guarantees delivery.

TCP is a connection-oriented protocol that ensures reliable, ordered delivery of data. UDP is faster but does not guarantee delivery. IP handles addressing, and FTP is an application protocol.

🚀 Application

advanced

What happens if a server socket is not bound to a port before listening?

Consider a server program that creates a socket but does not bind it to any port before calling listen(). What will be the result?

A The server will raise an error because binding to a port is required before listening.

B The server will listen on a random available port, making it hard for clients to connect.

C The server will listen on the default HTTP port 80 automatically.

D The server will accept connections but only from the local machine.

💡 Hint

Think about the role of binding in socket setup.

Binding assigns a specific port to the socket. Without binding, the server cannot listen on any port, so an error occurs.

🔍 Analysis

advanced

Why might a client socket fail to connect to a server socket?

Analyze the possible reasons a client socket cannot establish a connection to a server socket.

A All of the above.

B The client socket uses UDP instead of TCP to connect to a TCP server socket.

C Network firewall or security settings block the connection.

D The server is not running or not listening on the specified port.

💡 Hint

Consider all common causes of connection failure.

Connection failures can happen if the server is down, protocols mismatch, or network security blocks the traffic.

❓ Reasoning

expert

What is the effect of setting the socket option SO_REUSEADDR on a server socket?

Explain what happens when a server socket sets the SO_REUSEADDR option before binding.

A It encrypts the data sent through the socket for secure communication.

B It limits the number of simultaneous connections the server can accept.

C It allows the socket to bind to a port that is in the TIME_WAIT state, enabling quick restarts.

D It automatically closes the socket after a timeout period.

💡 Hint

Think about how servers restart quickly after closing connections.

SO_REUSEADDR allows a socket to bind to a port even if previous connections on that port are still in the TIME_WAIT state, which helps servers restart without waiting.