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How To Fix “ConnectionRefusedError: [Errno 111] Connection refused” in Python Sockets

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In the world of Python programming, it’s not uncommon to encounter errors and exceptions. One such error is the “ConnectionRefusedError: [Errno 111] Connection refused” which is often encountered when working with Python sockets. This error indicates that your connection request was rejected by the server or remote host. In this article, we will explore the causes of this error and how to fix it.

Quick Answer

To fix the "ConnectionRefusedError: [Errno 111] Connection refused" error in Python sockets, you need to verify that the IP address and port number specified in your code are correct and accessible. Additionally, check your firewall settings and network configurations to ensure that there are no rules or configurations blocking the connection. Finally, make sure that the server is actively listening for connections on the specified IP address and port.

Understanding Python Sockets

Before we delve into the error, it’s important to understand what Python Sockets are. Python’s socket module provides an interface to the BSD socket system calls and library routines for network communication. It allows for the creation of client-server applications and is particularly useful in scenarios where communication is required between Python programs running on different machines in a network.

Causes of the “ConnectionRefusedError: [Errno 111] Connection refused” Error

This error typically occurs due to one or more of the following reasons:

  1. Incorrect IP Address or Port Number: If the IP address or port number specified in your code is incorrect or unreachable, the connection request will be refused.
  2. Firewall Rules or Network Configurations: Connection requests can also be blocked by firewall rules or network configurations that prevent communication between the client and server.
  3. Server is not Listening: The error can occur if the server is not actively listening for connections on the specified IP address and port.

How to Fix the Error

Now that we understand the potential causes of the error, let’s discuss how to fix it.

Verify the IP Address and Port Number

Firstly, ensure that the IP address and port number specified in your Python code are correct and accessible. Here’s an example of how to create a socket and specify the IP address and port number:

import socket

s = socket.socket()
host = 'localhost' # IP address
port = 12345 # Port number

s.connect((host, port))

In this code, socket.socket() is used to create a socket object. The connect() method is then used to establish a connection with the server. The IP address and port number are passed as a tuple to this method.

Check Firewall Settings and Network Configurations

If the IP address and port number are correct, the next step is to check your firewall settings and network configurations. Ensure that there are no rules or configurations that are blocking the connection. This process will vary depending on your operating system and network setup, so refer to the appropriate documentation or IT support for guidance.

Ensure the Server is Listening

Finally, ensure that the server is actively listening for connections on the specified IP address and port. Here’s an example of how to set up a server to listen for connections:

import socket

s = socket.socket()
host = 'localhost' # IP address
port = 12345 # Port number

s.bind((host, port))
s.listen(5) # Listen for client connection

while True:
 c, addr = s.accept() # Establish connection with client
 print('Got connection from', addr)

In this code, socket.socket() is used to create a socket object. The bind() method is then used to bind the socket to the specified IP address and port number. The listen() method is used to set the socket to listening mode and accept() is used to wait until a client connects to the server.

Conclusion

In conclusion, the “ConnectionRefusedError: [Errno 111] Connection refused” error in Python sockets can be fixed by ensuring that the IP address and port number are correct, checking firewall settings and network configurations, and ensuring that the server is actively listening for connections. By understanding these aspects and following the suggested solutions, you should be able to resolve this error effectively.

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