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Cionnection Refused when running Python script

I am running the following python script within Oracle Virtualbox running Kali Linux and keep getting connection refused.
client.py
#!/usr/bin/python3
#client.py
import socket
client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = socket.gethostname()
port = 8080
client.connect((host, port)) # Connect to our client
msg = client.recv(1024)
client.close()
print (msg.decode('ascii'))
┌──(kali㉿kali)-[~/Downloads]
└─$ python3 client.py
Traceback (most recent call last):
File "/home/kali/Downloads/client.py", line 10, in <module>
client.connect((host, port)) # Connect to our client
ConnectionRefusedError: [Errno 111] Connection refused

I have solved this, the code is correct but I have not created a listner on port 8080.
Create a new python file name server.py and ran it.
Then ran my client.py
#!/usr/bin/python3
#server.py
import socket
host = socket.gethostname()
port = 8080
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.bind((host,port))
server.listen(2)
print('Server is listening for incoming connections')
while True:
conn,addr = server.accept()
print("Connection Received from %s" % str(addr))
msg = 'Connection Established'+ "\r\n"
conn.send(msg.encode('ascii'))
conn.close()

nonstop server client connection[Python]

I want to create a server-client connection that the client can always be connected to the server. How can I do it? Please help me. when I was trying, this error occurred.
"ConnectionResetError: [WinError 10054] An existing connection was forcibly closed by the remote host"
- code -
server:
import socket
try:
s=socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((host,port))
s.listen(1)
conn, addr=s.accept()
while True:
conn.send(("Test message").encode())
print((conn.recv(1024)).decode())
except Exception as error:
print(str(error))
client:
import socket
try:
s=socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((server_host,port))
while True:
print((s.recv(1024)).decode())
s.send(("Test message").encode())
except Exception as error:
print(str(error))

Some reasons cause this error message:
Server reused the connection because it has been idle for too long.
May be Client IP address or Port number not same as Server.
The network between server and client may be temporarily going down.
Server not started at first.
Your code seems to be OK. Did you run the Server at first time then client? Please make sure it. The below code fully tested on my computer.
Server:
import socket
HOST = '127.0.0.1' # (localhost)
PORT = 65432 # Port to listen on
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.bind((HOST, PORT))
s.listen()
conn, addr = s.accept()
while True:
data = conn.recv(1024).decode()
if not data:
break
conn.send(data.encode())
Client
import socket
HOST = '127.0.0.1' # Server's IP address
PORT = 65432 # Server's port
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.connect((HOST, PORT))
while True:
s.send(("Hi server, send me back this message please").encode())
data = s.recv(1024).decode()
print('(From Server) :', repr(data))
Note: Run the Server first then Client.
Output:

i have some problems making a tcp server form a book in python , it shows OS error

import socket
import threading
bind_ip = '192.168.43.233'
print(f"[*] connecting to " + bind_ip)
bind_port = 443
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.listen(5)
print(f"[*] Listening on %s:%d" % (bind_ip,bind_port))
def handle_client(client_socket):
request = client_socket.recv(1024)
print(f"[*] Recieved: %s" % request)
client_socket.send("ACK!")
client_socket.close()
while True:
client,addr = server.accept()
print(f"[*] Accepted connection from: %s:%d" % (addr[0],addr[1]))
client_handler = threading.Thread(target=handle_client,args=(client,))
client_handler.start()
says this when running
Traceback (most recent call last):
File "C:/Users/Red/PycharmProjects/untitled4/TCP SERVEr.py", line 9, in <module>
server.listen(5)
OSError: [WinError 10022] An invalid argument was supplied
any help with this so much appreciated ive been dealing with this for days now and looked everywhere but found nothing

You can't call server.listen() until you bind the socket to a port.
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.bind((bind_ip, bind_port))
server.listen(5)

You need to bind the socket before server.listen(5).
connection.bind((bind_ip, bind_port))

Python Socket Programming - ConnectionRefusedError: [WinError 10061] No connection could be made because the target machine actively refused it

I'm doing an assignment regarding socket programming in python using a client and server. I'm currently on windows 10. Before getting into the little details of the assignment, I've been trying to simply connect the server and client.
Every time I try to run the client file, I would get this error
File "tcpclient.py", line 9, in <module>
s.connect((host, port))
ConnectionRefusedError: [WinError 10061] No connection could be made because the target machine actively refused it
I have opened the firewall ports and still nothing. I've tried replacing host with '', 0.0.0.0, socket.gethostname() in both the client and server file but the error still persists. I've even tried different port numbers but it made no difference. I've tried running this code on Ubuntu and Max and I get the same error - connection refused. I've been researching for many solutions but I still have yet to find one that works. Any help would be greatly appreciated!
Note: this code was taken online but it's essentially the basis of what I need to accomplish.
tcpclient.py
import socket
host = '127.0.0.1'
port = 80
buffer_size = 1024
text = "Hello, World!"
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((host, port))
s.send(text)
data = s.recv(buffer_size)
s.close()
print("received data:", data)
tcpserver.py
import socket
host = '127.0.0.1'
port = 80
buffer_size = 20
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((host, port))
s.listen(1)
conn, addr = s.accept()
print 'Connection address:', addr
while 1:
data = conn.recv(buffer_size)
if not data: break
print("received data:", data)
conn.send(data) # echo
conn.close()

Just use a different port. Both the client and server should have the same port and host if not it won't work. Make sure to run the server before the client script.

For client.py
import socket
host = '127.0.0.1'
port = 9879
buffer_size = 1024
text = "Hello, World!"
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((host, port))
text = text.encode('utf-8')
s.send(text)
data = s.recv(buffer_size)
s.close()
print("received data:", data)
For server.py
import socket
mysocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
buffer_size = 1024
text = "Hello, World!"
mysocket.bind(('127.0.0.1', 9879))
mysocket.listen(5)
(client, (ip,port)) = mysocket.accept()
print(client, port)
client.send(b"knock knock knock, I'm the server")
data = client.recv(buffer_size)
print(data.decode())
mysocket.close()
Just change the port number and it will work and if you are in python3 then you will have to encode and decode as socket recieves and sends only binary strings.

I have succeed in my server!
My server python script is below:
import socket
host='0.0.0.0'
port=2345
s=socket.socket()
s.bind((host,port))
s.listen(2)
while True:
conn,addr=s.accept()
print("Connected by",addr)
data=conn.recv(1024)
print("received data:",data)
conn.send(data)
conn.close()
My Client python script is below:
import socket
s=socket.socket()
host="xx.xx.xx.xx" #This is your Server IP!
port=2345
s.connect((host,port))
s.send(b"hello")
rece=s.recv(1024)
print("Received",rece)
s.close()
There is two points needed to be careful in the script:
1.The host of the Server must is
'0.0.0.0'
So that the python script could user all interfaces in the server
2.I have find the question's error through the prompt:
TypeError: a bytes-like object is required, not 'str'
It means every string message in the 'send' method need to convert to 'bytes-like object',So the correct is
s.send(b"hello")
It is important that this is b'hello' not is 'hello'

I was following a tutorial that used threading to start the server. Once I removed the threading then I was able to connect to it.

how to reproduce "Connection reset by peer"

I have learned the differences between the two infamous errors in tcp:
[Errno 54] Connection reset by peer
[Errno 32] Broken pipe
Both errors are one side of the tcp connection closed for unknown reason, and the other side still communicate with it.
when the other side write something, Broken pipe is thrown
when the other side read something, Connection reset by peer is thrown
I was able to reproduce Broken pipe using Python codes below.
# tcp_server.py
def handler(client_sock, addr):
try:
print('new client from %s:%s' % addr)
finally:
client_sock.close() # close current connection directly
if __name__ == '__main__':
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.bind(('', 5500))
sock.listen(5)
while 1:
client_sock, addr = sock.accept()
handler(client_sock, addr)
As for client,
>>> sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
>>> sock.connect(('', 5500))
>>> sock.send('a')
1
>>> sock.send('a')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
socket.error: [Errno 32] Broken pipe
When the client first send, a RST packet is sent from server to client, from this moment on, send will always throw Broken pipe.
Everything above is within my understanding. However when client read from server , it always return empty string instead of throw Connection reset by peer
>>> sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
>>> sock.connect(('', 5500))
>>> sock.recv(1024)
''
>>> sock.recv(1024)
''
>>> sock.recv(1024)
''
>>> sock.recv(1024)
I am confused at this, or generally how to reproduce the Connection reset by peer ?

You can set the socket "linger" option to 0 and close the socket to send a reset. Updating your server
import socket
import struct
import time
# tcp_server.py
def handler(client_sock, addr):
try:
print('new client from %s:%s' % addr)
time.sleep(1)
finally:
client_sock.setsockopt(socket.SOL_SOCKET, socket.SO_LINGER,
struct.pack('ii', 1, 0))
client_sock.close() # close current connection directly
if __name__ == '__main__':
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.bind(('', 5500))
sock.listen(5)
while 1:
client_sock, addr = sock.accept()
handler(client_sock, addr)
And running this client
import socket
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect(('', 5500))
print(sock.recv(1024))
I got
Traceback (most recent call last):
File "tcpclient.py", line 5, in <module>
print(sock.recv(1024))
ConnectionResetError: [Errno 104] Connection reset by peer