Learn F5 Technologies, Get Answers & Share Community Solutions Join DevCentral

Filter by:
  • Solution
  • Technology

TCP Keepalive v HTTP Keepalive?

What is Difference? by Default, HTTP 1.1 Keep as 15 seconds for connection TCP profile for 300 Seconds for connection

        How HTTP VIP will handle the traffic? 
        Will every 15 seconds, it make new  connection? and override the TCP profile settings?
        Will every 300 seconds, it make new  connection? and override the HTTP  profile settings?
Rate this Question

Answers to this Question


HTTP Keep-alive timeout is mostly controlled by the server. Example, Server says, if you don't send me a request, after 15 seconds of idleness, I will close the connection.

When server closes the connection, the TCP idle timeout is irrelevant, because connection is explicitly being closed.

So in effect, http keep-alive timeout overrides the TCP one. If conneciton is closed for any reason, then client must initiate a new connection to send a new request.

The TCP idle timeout is only in effect if the connection is idle (no data transmitted) and the connection was not closed for any other reason (such as http keep-alive timeout). You can think of it as the default timeout when nothing else closes the connection.

Comments on this Answer
Comment made 22-Sep-2017 by BinaryCanary

Note, it is an idle timeout. It is not a "maximum lifetime". A TCP connection can live forever if it is not closed due to any other reason (error, timeout, power failure, nuclear apocalypse), as long as it does not remain idle for more than 300 seconds (default config).