title: How to run pycrate corenet
body: <p>I want to run the core simulator of <a href="https://github.com/P1sec/pycrate" rel="nofollow noreferrer">https://github.com/P1sec/pycrate</a>.
  And I want to run SERVER_ENB only, so configure like below and create a server.</p>
  
  <pre><code>from pycrate_corenet import Server
  
  Server.CorenetServer.SERVER_HNB = {}
  Server.CorenetServer.SERVER_ENB['IP'] = '127.0.0.1'
  Server.CorenetServer.SERVER_ENB['GTPU'] = '127.0.0.1'
  
  epc = Server.CorenetServer()
  </code></pre>
  
  <p>But, I got following error.</p>
  
  <pre><code>$ sudo /usr/local/anaconda3/bin/python EPC.py 
  CorenetServer: loading all ASN.1 and NAS modules, be patient...
  Exception in thread Thread-1:
  Traceback (most recent call last):
    File "/usr/local/anaconda3/lib/python3.6/threading.py", line 916, in _bootstrap_inner
      self.run()
    File "/usr/local/anaconda3/lib/python3.6/threading.py", line 864, in run
      self._target(*self._args, **self._kwargs)
    File "/usr/local/anaconda3/lib/python3.6/site-packages/pycrate-0.3-py3.6.egg/pycrate_corenet/Server.py", line 345, in start
      self.GTPUd = self.__class__.GTPUd()
    File "/usr/local/anaconda3/lib/python3.6/site-packages/pycrate-0.3-py3.6.egg/pycrate_corenet/ServerGTPU.py", line 466, in __init__
      sk.bind((gtpip, self.GTP_PORT))
  OSError: [Errno 99] Cannot assign requested address
  </code></pre>
  
  <p>How can I run the server?
  Could you give a usage for this pycrate corenet?</p>