title: Python telnetlib read_all hangs until timeout
body: <p>I have some Python code that connects via telnet to an OSPF daemon (ran by Quagga) and then does the following:  </p>
  
  <pre><code>tn.write("show ip ospf database router\n")
  tn.write("exit\n")
  my_text = tn.read_all()
  </code></pre>
  
  <p>When the output of <strong>show ip ospf database router</strong> is small, the script works fine, but when it is big (approximately 73kb) the code freezes in the <strong>read_all()</strong> call until it timeouts.</p>
  
  <p>My question is: why is this happening? Is there some sort of maximum size of output that read_all can handle?</p>
  
  <p>I should note that if I use <strong>read_very_eager()</strong> instead of <strong>read_all()</strong> the code works fine.</p>
  
  <p>Thank you in advance.
  Santiago Vidal.</p>