Why am I getting the error "connection refused" in Python? (Sockets)

Question

I'm new to Sockets, please excuse my complete lack of understanding.

I have a server script(server.py):

#!/usr/bin/python

import socket #import the socket module

s = socket.socket() #Create a socket object
host = socket.gethostname() #Get the local machine name
port = 12397 # Reserve a port for your service
s.bind((host,port)) #Bind to the port

s.listen(5) #Wait for the client connection
while True:
    c,addr = s.accept() #Establish a connection with the client
    print "Got connection from", addr
    c.send("Thank you for connecting!")
    c.close()

and client script (client.py):

#!/usr/bin/python 

import socket #import socket module

s = socket.socket() #create a socket object
host = '192.168.1.94' #Host i.p
port = 12397 #Reserve a port for your service

s.connect((host,port))
print s.recv(1024)
s.close

I go to my desktop terminal and start the script by typing:

python server.py

after which, I go to my laptop terminal and start the client script:

python client.py

but I get the following error:

File "client.py", line 9, in

s.connect((host,port))

File "/usr/lib/python2.7/socket.py", line 224, in meth

return getattr(self._sock,name)(*args)

socket.error: [Errno 111] Connection refused

I've tried using different port numbers to no avail. However, I was able to get the host name using the same ip and the gethostname() method in the client script and I can ping the desktop (server).

Answer 1

Instead of

host = socket.gethostname() #Get the local machine name
port = 12397 # Reserve a port for your service
s.bind((host,port)) #Bind to the port

you should try

port = 12397 # Reserve a port for your service
s.bind(('', port)) #Bind to the port

so that the listening socket isn't too restricted. Maybe otherwise the listening only occurs on one interface which, in turn, isn't related with the local network.

One example could be that it only listens to 127.0.0.1, which makes connecting from a different host impossible.