title: Python ipwhois ASN Registry Error
body: <p>I am using <code>ipwhois</code> for the first time. Running the basic usage example with a Google IP address works:</p>
  
  <pre><code>from ipwhois import IPWhois
  obj = IPWhois('74.125.225.229')
  results = obj.lookup_rdap(depth=1)
  </code></pre>
  
  <p>Any other IP address results in this error:</p>
  
  <pre><code>ASNRegistryError                          Traceback (most recent call last)
  &lt;ipython-input-62-03afc25be9cd&gt; in &lt;module&gt;()
  ----&gt; 1 results = obj.lookup_rdap(depth=1)
  
  ~\_installed\anaconda\envs\geocode\lib\site-packages\ipwhois\ipwhois.py in lookup_rdap(self, inc_raw, retry_count, depth, excluded_entities, bootstrap, rate_limit_timeout, asn_alts, extra_org_map, inc_nir, nir_field_list, asn_methods, get_asn_description)
      306                 inc_raw=inc_raw, retry_count=retry_count, asn_alts=asn_alts,
      307                 extra_org_map=extra_org_map, asn_methods=asn_methods,
  --&gt; 308                 get_asn_description=get_asn_description
      309             )
      310 
  
  ~\_installed\anaconda\envs\geocode\lib\site-packages\ipwhois\asn.py in lookup(self, inc_raw, retry_count, asn_alts, extra_org_map, asn_methods, get_asn_description)
      569         if asn_data is None:
      570 
  --&gt; 571             raise ASNRegistryError('ASN lookup failed with no more methods to '
      572                                    'try.')
      573 
  
  ASNRegistryError: ASN lookup failed with no more methods to try.
  </code></pre>
  
  <p>I attempted to switch the lookup method to ARIN with <code>bootstrap=True</code> to no avail. How do I remedy this error?</p>