I can't connect to socket from the outside

Question

Hi everyone, I am trying to make a simple server/client program pair. On LAN they work fine, but when i try to connect from the "outside" it says connection refused. I shut down firewalls on both machines but i am still unable to connect, and i double checked the ip.

What am i doing wrong?

Thanks

Jake

Code:

import socket 
host = '' 
port = 9888 
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) 
s.bind((host,port))     
s.listen(1) 
conn, adrr = s.accept() 
conn.send("Hello, world!") 
s.close() 

Client: 
import socket 
host = '68.x.x.x'
port = 9888
s = socket.socket(socket.AF_INET, socket_SOCK_STREAM)
s.connect((host,port)) 
print s.recv(200) 
s.close() 

Answer 1

How's the argument you're passing to the .bind call for your server socket? That's the single likeliest cause -- e.g. if you're using 192.168.x.y for whatever values of x and y, or 10.x.y.z likewise, that's a local-network address only, not routed by inter-network routers by internet conventions (most routers can be programmed to forward some incoming packets to a specific local-network address, typically depending on ports, but that's very specific to router's brands and models).

Answer 2

You have one of two possible issues.

1. Erroneous network configuration
2. Bug(s) in code

The way to debug this is to try and rule one out. If we can get rid of the Code issue then we know it is a network issue.

Get a Socket Server and client that you know works and then try them as standalone programs. inside and outside of the firewall. Go to this site and download the examples. Change the ports in both the client and the server, compile and run them. First on same machine within network, second from two machines on same network and then server from within and client from outside of network.