SSH Connection

Keep SSH Connected

There is always one issue that bothers me when using SSH to access server (e.g. EC2) which is that the ssh connection can disconnect very soon. I tried to make changes in the local ssh config: ~/.ssh/config

Host remotehost
	HostName remotehost.com
	ServerAliveInterval 50

Then do a permission change

chmod 600 ~/.ssh/config

However, this doesn’t work for me on Mac, and I don’t know why. :(

Then I tried to make changes on server side. In /etc/ssh/sshd_config, add or uncomment the following lines:

ClientAliveInterval 50
ClientAliveCountMax 10

Then restart or reload SSH server to help it recognize the configuration change

sudo service ssh restart  # for ubuntu linux
sudo service sshd restart  # for other linux dist

Finally, log out and try to login again

logout

This time it works! :)

Adding SSH Public Key to Server

Adding ssh public key to server sometimes can make the connections eaiser. The command is simple:

cat ~/.ssh/id_ras.pub | ssh -i "my-keypair.pem"  ubuntu@myserver 'cat >> ~/.ssh/authorized_keys'

SSH Config

We can add the following into the ssh config file so that we can directly ssh pdn into the server. Note that here hostname doesn’t have username, i.e. it’s not Hostname ubuntu@my.compute.aws.com.

# in .ssh/config

Host pdn
    Hostname  my.compute.cloud.com
    User ubuntu
    IdentityFile ~/.ssh/id_rsa