[FIXED] How can i connect two computers with python socket?

Issue

im new here! I have a problem with connection between two computers connected with different wi-fi's. After about 20 seconds i get information that connection can't be done. There is my code: SERVER:

from socket import *


lista = ['computer']

s = socket(AF_INET, SOCK_STREAM)

port = 21312
s.bind(('my ipv4', port))

s.listen(5)
while True:

for i in range (0, len(lista)):
    a = str(lista[i]).encode()
    c, addr = s.accept()
    print("CONNECTION WITH",addr)
    c.send(a)
    print(a)
    c.close()

CLIENT:

import socket
from socket import *

port = 21312

while True:
s = socket(AF_INET,SOCK_STREAM)
s.connect(('my ipv4', port))
odebrana = (s.recv(1024))
decoded = odebrana.decode()
print(decoded)
s.close()

Solution

Likely you are experiencing an issue because your server sits behind a Network Address Translator (NAT). This way your client cannot use the server's IP directly since it is not reachable. There are a few ways around it.

1. The easiest and not very practical one is: get both machines in the same network, then it should work.
2. Get a public IP address for the server. You can do that by hosting it on a cloud server that provides you with a public IP, e.g., aws, azure, google cloud etc.
3. In the old days we used hamachi to get a VPN that would connect both machines. Then they can identify each other over that VPN. Simply turn on hamachi (or any other VPN solution), run your server, then from your client (connected to the VPN), use the VPN's server IP (hamachi will provide you with one when you setup a network).

Disclaimer: I have not used hamachi in about 15 years, but just went through the process because of one of the comments below.

Seems like you can create an account, then once you turn it on you should see your v4 and v6 addresses as shown below:

Highlighted is my v4 address. I suspect you need to create a network, join both PCs in the same network and then use hamachi's IP to emulate behaviour as if they were connected via LAN.

Answered By - Misho Janev

Answer Checked By - Marie Seifert (PHPFixing Admin)