The system’s default settings send nine probes at 75-second intervals, totaling 675 seconds, after which the session is considered failed and closed. However, this does not mean your SSH session will be kept alive for 2 hours, as the following two parameters are crucial. What does it all mean? Keepalive time is 7200 seconds, or 120 minutes (2 hours). cat /proc/sys/net/ipv4/tcp_keepalive_timeĬat /proc/sys/net/ipv4/tcp_keepalive_probesĬat /proc/sys/net/ipv4/tcp_keepalive_intvl Checking keepalive values in Linux. tcp_keepalive_intvl: controls the interval between sending keepalive probes on an idle TCP connection.Įach value is in seconds and can be easily checked with the commands below.It detects if the remote endpoint has become unreachable or the connection has been lost due to network issues. tcp_keepalive_probes: a small packet sent by a TCP endpoint to check the health and responsiveness of the remote endpoint in an idle connection.

Keepalive probes check whether a remote peer is still alive and responsive, even when no data is being transferred. tcp_keepalive_time: determines the interval between sending out TCP keepalive probes on an idle TCP connection.In the case of keeping the SSH connection alive, there are three key system parameters that we will briefly discuss below. This mechanism is crucial for ensuring that network communication is reliable and efficient. In Linux, TCP timeout settings determine how long a TCP connection or operation should wait before assuming that a packet has been lost or a connection has become unresponsive. TCP timeout refers to the duration that a TCP connection or a network operation waits for a response before considering the process failed. The short answer is that it all comes down to TCP timeouts. But before we move forward, let’s answer an important question. So, say goodbye to frustration and hello to efficient, uninterrupted SSH sessions. This comprehensive guide unveils the secrets to maintaining active and responsive SSH connections, ensuring a seamless experience devoid of freezing troubles. Moreover, the sudden disruption of a session can lead to lost work, delayed projects, and a sense of helplessness.īut fear not, for there is a solution at hand.

However, its convenience and security can sometimes be marred by a common frustration: frozen SSH sessions. In remote server management and secure data transfer, SSH (Secure Shell) stands as an indispensable tool.

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