title: telnetlib python read_all() not working(hangs)
body: <p>I am trying to read from a cisco router using telnetlib </p>
  
  <pre><code>import telnetlib
  tn = telnetlib.Telnet(’10.106.218.50’, 17280)
  cmd1=”enable”
  cmd2=”show run”
  #session.write("command".encode('ascii') + b"\r")
  tn.write(cmd1.encode('ascii') + b"\r")
  tn.write(cmd2.encode('ascii') + b"\r")
  #op=tn.read_very_eager()
  #op=tn.read_some()
  #op=tn.read_until('#')
  op=tn.read_all()
  print op
  </code></pre>
  
  <p>I am able to write to the console of the router successfully
  However the system just hangs,when i try to read from the console of the router.
  <strong>When i use read_some(), i get a part of the output</strong>.But read_all() just hangs and gives no response 
  Please suggest a solution</p>