Generally, in python, the connection error is not something that you will face every day, but it can sometimes happen due to various reasons. One such reason is the connection Refuse. This causes the generation of ConnectionRefusedError errno 111 connection refused message. If you are facing this error message in your coding, this might help you.
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What is socket error?
A socket programming in python is used to form a bidirectional communications channel. It is generally a process of making the two unrelated network nodes communicate with each other by making a connection. This connection can be made if you know the IP address of the server.
What is ConnectionError?
Whether you are someone new to the python language or not, you must be aware of the term connection error. As suggested by the name, it is a class of exception errors related to the errors generated due to issues in the connection. It is a type of socket error that is observed in many other libraries and platforms.
In python, the ConnectionError is generally referred to as an error generated by the failure in any of the internal connections that are the connection between the application and the DBMS server mediating a peer. This type of error can be caused by various failures, such as local errors caused by the errors reported directly to the user interface programs, then local and remote errors caused while trying to connect from the local communication server to the remote communication server and the server installation. These ConnectionErrors also report directly to the applications.
Types Of ConnectionError
There are mainly three subclasses of ConnectionError such as ConnectionAbortedError, ConnectionResetError, and ConnectionRefusedError. These errors generally arise when the error is raised due to the attempt the interruption in connection with the actions of peers.
What does ConnectionRefusedError errno 111 connection refused mean?
The ConnectionRefusedError errno 111 connection refused is a subclass of the ConnectionError which is caused when the peer refuses the attempts for the connection between the application and the server. This type of error corresponds to errno ECONNREFUSED messages.
The ConnectionRefusedError errno 111 connection refused is generated when the initial SYN packet to the host to be connected was responded with an RST packet instead of a SYN+ACK packet. This resulted in the declination of the program on the remote computer that needed to be connected.
This type of error can cause by many libraries and computing platforms, but the solutions to this problem are similar.
The generation of the error can be understood efficiently by using an example:
As the connection has to be made from both end so it is done in two parts:
The Server script:
The client script:
These codes might seem good, but this will result in the socket.error: [Errno 111] Connection refused message.
How to solve the ConnectionRefusedError errno 111 connection refused?
As this is a connection-based error, so the errors have to be checked on both ends that is, on the client and the server end. The ConnectionRefusedError errno 111 connection refused can be resolved using one of the following reasons.
Checking the connection
- Ensure the IP address is of the client, and both servers are on the same LAN. If the servers are not on the same router or firewall, then you may face traffic blocking.
- Make sure that the port is listening to the server and if not then try “netstat -ntulp”.
- Make sure that you are accepting the connections to the server.
- Make sure you have access to the port server of the client.
Selectively restrict the listening socket
In the example for the generation of the ConnectionRefusedError by the server you can see that there is a line as follows:
host = socket.gethostname() #Get the local machine name
port = 98406 # Reserve a port for your service
s.bind((host,port)) #Bind to the portInstead of the above code, you can try:
port = 98406 # Reserve a port for your service
s.bind(('', port)) #Bind to the portThis way, the listening socket will not be too restricted and will ensure the connection precisely on both ends.
Proper guidance to get an IP address
To avoid ConnectionRefusedError errno 111 connection refused while coding you need to make sure to get the right IP address for that you have to put the hostname and port number for the receiver end correctly.
Due to DNS resolution, the hostname might not get translated into the local address and returned properly. So instead of the usual code:
host = socket.gethostname() #Get the local machine name
port = 98406 # Reserve a port for your service
s.bind((host,port)) #Bind to the portYou can try the code below.
host = socket.gethostbyname("localhost")
s.connect((host, port))FAQ
How do you fix a socket error?
As the ConnectionRefusedError errno 111 connection refused is a type of socket error, resolving this may help in resolving the former error.
- This error can be fixed by specifying the port number for which you can use the following code:
m SimpleHTTPServer (Port Number)- You can also free up the port by terminating the previous programs.
What is the socket address in computer networks?
The socket address is a crucial part of establishing the connection. It is generally a combination of two identifiers, that is both IP address and port number. It is defined in a header where it is specified by a data structure.
Conclusion
The ConnectionRefusedError errno 111 connection refused is a socket error that results when there is a failure in the establishment of connection when the connection is refused. Which can later be resolved by managing the data necessary for establishing the connection.
References
- Dizzy coding
- GeeksforGeeks socket programming
To learn more about some common errors follow python clear’s errors section.
