Opening socket to outside computer with Python

Question

I am using the following code to open a socket on my computer. When I go to my_ip:5000 on my computer the program responds. However, when I use another computer, nothing happens.

HOST = 'my_ip'                 # Symbolic name meaning the local host
PORT = 8000              # Arbitrary non-privileged port
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(1)
conn, addr = s.accept()
print 'Connected by', addr
while 1:
    data = conn.recv(1024)
    if not data: break
    conn.send(data)
conn.close()

I'm not sure if this is an issue with the firewall or not. When I start up the test server in django using manage.py runserver my_ip:8000 I am able to connect to the machine from a different computer. I'm not sure what is causing me not to be able to connect from another computer using the code above...

Are you trying to reach the server from outside your local network? If that's the case, check if you've forwarded the port correctly. If you're trying to access it from a computer in the same network, be sure to use the internal IP and not the external. — Griffin
– Griffin, Commented Oct 20, 2011 at 18:39
Yes, when I type my_ip in to the machine the above code is running on it works. However when I use a different machine, nothing. — Alexis
– Alexis, Commented Oct 20, 2011 at 19:44

phihag · Accepted Answer · 2011-10-20 18:52:53Z

9

By setting HOST to 'my_ip', you may listen to a private IP that only resolves to your computer for your computer. The best-known example is 127.0.0.1. Instead, pass an empty string (HOST='') to listen to any requests coming in at the specified port. Make sure to use the same port number, i.e. either 5000 or 8000, on both machines.

Also, check whether a firewall between the computers (or installed on one of them) prevents the connection.

To test whether your computer is reachable in principle, run python -m SimpleHTTPServer in a directory without private information on the server and try to reach the webserver started with that from the client.

edited Oct 20, 2011 at 18:52

answered Oct 20, 2011 at 18:42

phihag

289k75 gold badges475 silver badges489 bronze badges

Sign up to request clarification or add additional context in comments.

7 Comments

Alexis Over a year ago

Thanks for the reply. I tried the -m SimpleHTTPServer and it worked on the local machine but not a remote machine. In Django, when I run manage.py runserver my_ip:8000 I am able to use a remote machine to access files. Could this be an issue with the firewall? I'm using Windows 7.

phihag Over a year ago

@AlexisK Yes, it could definitely be the local firewall. The result of running django and running the SimpleHTTPServer should definitely be the same though. Are you certain the IP is correct? By the way, you may want to use a packet dumper such as wireshark (potentially on both machines) to debug the problem.

Alexis Over a year ago

Yeah, I through running the django and SimpleHTTPServer should be the same but for some reason it is not :( I tried SimpleHTTPServer in the exact folder that I ran runserver in and it didn't work.

phihag Over a year ago

@AlexisK That strongly indicates the firewall. Does it work if you temporarily disable the Windows firewall? What does wireshark display?

Alexis Over a year ago

I turned off the firewall and same behavior. runserver works as expected SimpleHTTPServer does not. ;( SimpleHTTPServer says "Serving HTTP on 0.0.0.0 port 8000"

|

Raymond Hettinger · Accepted Answer · 2011-10-20 18:46:47Z

2

The code looks to be correct, so your problem lies elsewhere (perhaps a firewall issue or dns problem for "my_ip").

answered Oct 20, 2011 at 18:46

Raymond Hettinger

229k67 gold badges405 silver badges504 bronze badges

Collectives™ on Stack Overflow

Opening socket to outside computer with Python

2 Answers 2

7 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

7 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related