title: OSError [Errno 99] - python
body: <p>i want to execute the following simple server code: </p>
  
  <pre><code>import socket
  
  s = socket.socket()         # Create a socket object
  host = socket.gethostname() # Get local machine name
  port = 22331                # Reserve a port
  s.bind((host, port))        # Bind to the port
  
  s.listen(5)                 # Now wait for client connection.
  while True:
     c, addr = s.accept()     # Establish connection with client.
     print('Got connection from', addr)
     c.send('Thank you for connecting')
     c.close() 
  </code></pre>
  
  <p>gives the following error while executing: </p>
  
  <pre><code>OSError: [Errno 99] Cannot assign requested address
  </code></pre>
  
  <p>why the OS cannot bind the specified port with the address?</p>