ssh reads configuration information from a config file (if you have one) before connecting to a machine. This way you can tell ssh how you want to connect toparticular machines. If you have a lot of different machines that you connect to, especially if youconnect to them on different ports and with different user names then it is a great idea to create the following file .ssh/config type vi .ssh/config and popultate the config file with the information of the machines that you connect to. eg Host *netaxiz.com Port 2222 User clive Host ipcop1 Port 222 User root Host home Hostname 192.168.0.10 User clive Port 768 with the above information in the config file if you typessh machine.netaxiz.com will be the equivalent of typing ssh -p 2222 firstname.lastname@example.org and typing scp file1 ipcop1:file1 will be the equavelent of typing scp -P222 file1 root@ipcop1 as you can see the config file can save you a lot of time. The port and the username from the config file will automatically be used every time you connect to the machines listed in the config file. Were this is especially usefull is when you want to copy ssh keys to a remote machine using the ssh-copy id command when the remote machine uses a different port to 22. Lets say you want to copy your public keys to your machine called home but machine home only allows ssh connection on port 768. By adding in the information above for machine home. I can now simply type ssh-copy-id -i ~/.ssh/id_rsa.pub home to transfer the keys.
if you get the following error when using ssh Bad owner or permissions on .ssh/config then you must change the permissions of the config file.
chmod 600 config