TCP Keep Alive
TCP keepalive means that GCC can check the connected session and determine whether the TCP connection is alive or has been interrupted.
When this option is enabled, the TCP subsystem starts monitoring the socket traffic. If there is no activity for a certain timeout (specified by the Idle timeout value), the TCP subsystem starts sending keepalive packets. Typically, this is no more than 10 packets with an interval of one second. If there is no response to any of the packets, the connection is closed.
This mechanism is used by GCC to terminate hung sessions. A hung session is any interruption of the connection with the client. This can be a client application crash, a network adapter or cable disconnection, a client reboot, etc. In this case, the hung session continues to occupy the network resource until the inactivity timeout expires. At this point, the occupied network resource cannot be reused.
If the client application terminates normally, GCC closes the session and releases the network resource immediately.
To check the TCP keepalive settings follow the steps below:
- In the upper right corner, click the Settings icon.
- Enter your password and click Login.
- Select the Session page.
- Make sure the Keep TCP active switch is set to On.
- Set the Idle timeout in minutes (default is 120 minutes).
- Click Submit.
