title: network unavailable from python script
body: <p>I tried to access wikipedia page from python</p>
  
  <pre><code>a = urllib2.urlopen("http://en.wikipedia.org/wiki/LALR_parser")
  </code></pre>
  
  <p>this caused an error </p>
  
  <pre><code>&lt;urlopen error [Errno 101] Network is unreachable&gt;
  </code></pre>
  
  <p>So I tried</p>
  
  <pre><code>req = urllib2.Request(url, headers={'User-Agent' : "MyBrowser"})
  a = urllib2.urlopen(req)
  </code></pre>
  
  <p>Still I get the same error</p>
  
  <p><strong>Now I am unable to view wikipedia in chrome or firefox</strong>..It says 'chrome cannot find the page'</p>
  
  <p>But if I type in the wikipedia url in an anonymous proxy ,the page is displayed without any problem</p>
  
  <p>What do you think is the problem?Is my IP blocked? I checked firewall(in ubuntu lucid)</p>
  
  <pre><code>sudo ufw status
  
  Status: inactive
  </code></pre>
  
  <p>I also tried</p>
  
  <pre><code>sudo iptables -L -n
  Chain INPUT (policy ACCEPT)
  target     prot opt source               destination         
  
  Chain FORWARD (policy ACCEPT)
  target     prot opt source               destination         
  
  Chain OUTPUT (policy ACCEPT)
  target     prot opt source               destination
  </code></pre>
  
  <p>can somebody please help?</p>