SSH Connection Freezes after being inactive for few minutes? We can help you.

Here, at Bobcares, we assist several of our customers with errors as part of our Server Management Services.

In this article, let us see how our techs resolve this issue.

SSH Connection Freezes

Most often the ssh terminal freezes after being inactive for few minutes.

We can try to change the /etc/ssh/sshd_config to the following:

TCPKeepAlive yes
ClientAliveInterval 30
ClientAliveCountMax 99999

However, the restart of the ssh daemon service will not work.

Moving ahead, let us see how our Support Techs fix this issue for our customers.

First and foremost, we make these configuration changes on the client:

/etc/ssh/ssh_config
Host *
ServerAliveInterval 100

Here, the ServerAliveInterval means the client will send a null packet to the server every 100 seconds to keep the connection alive.

A NULL packet is sent by the server to the client. Similarly, the client sends the same packet to the server.

Then we configure the sshd part on the server:

/etc/ssh/sshd_config

ClientAliveInterval 60
TCPKeepAlive yes
ClientAliveCountMax 10000

In this case, clientAliveInterval indicates, the server will wait 60 seconds before sending a null packet to the client to keep the connection alive.

We have TCPKeepAlive to ensure that certain firewalls don’t drop idle connections.

ClientAliveCountMax Server will send alive messages to the client even if it does not receive any message back from the client.

Finally, we restart the ssh server:

service ssh restart or service sshd restart

This depends on the system we are on.

[Stuck in between? We are here for you 24*7]

Conclusion

In short, we saw how our Support Techs fix the SSH connection error.