Definitions for "keepalive "
Powerful yet small, keepalive is a script that monitors vital applications and takes the necessary actions to insure the high availability of those core applications on your machines. Utilizing a modular method for the monitoring scripts, the level of complexity for those scripts is entirely in the hands of the systems administrator.
A server feature which keeps a TCP connection open after fulfilling an initial request in order to fulfill subsequent requests. Keepalive minimizes the server overhead normally required to open and close an individual connection for each request.
Keywords:  sent, message, virtual, device, still
A message sent by one network device to inform another network device that the virtual circuit between the two is still complete and functioning.
A keepalive is a message sent by one device to another to check that the link between the two is operating.