title: When is TCP option SO_LINGER (0) required?
body: <p>I think I understand the formal meaning of the option. In some legacy code I'm handling now, the option is used. The customer complains about RST as response to FIN from its side on connection close from its side.</p>
  
  <p>I am not sure I can remove it safely, since I don't understand when it should be used.</p>
  
  <p>Can you please give an example of when the option would be required?</p>