tcpkeepaliveintvl

tcpkeepaliveintvl is a kernel parameter that controls the interval between keepalive probes sent by the TCP stack when a connection is idle. It is a sub-parameter of tcpkeepalive probes, which are designed to detect and terminate dead connections.

When TCP keepalive is enabled, the operating system periodically sends a probe packet to the other end of an idle connection. If no response is received after a certain number of probes, the connection is considered to be dead and is closed. The tcpkeepaliveintvl parameter determines how often these probes are sent.

The default value for tcpkeepaliveintvl varies depending on the operating system, but it is often set to 60 seconds. A lower value will result in more frequent probes, which can help to detect dead connections more quickly. However, it can also increase network traffic and consume more system resources. A higher value will reduce network traffic but may lead to longer detection times for dead connections.

This parameter is typically adjusted on systems that experience frequent network interruptions or where quick detection of unresponsive hosts is critical. For most general-purpose systems, the default value is usually sufficient. Modifying this value should be done with an understanding of the trade-offs between rapid dead connection detection and network overhead.