Like changing password at times, it is good practice to change your SSH key at times. But updating all servers with your new SSH key can be time consuming. Here is what i done to change my SSH key.

First i renamed my .ssh folder to .ssh-old

mv ~/.ssh ~/.ssh-old

Now generate new SSH keys with command

ssh-keygen -t rsa -b 4096 -C "[email protected]"

Lets remove SSH key cache with command

ssh-add -D

Add new and old SSH keys back in

ssh-add ~/.ssh/id_rsa
ssh-add ~/.ssh-old/id_rsa

Verify both keys are listed with command

ssh-add -l

Now you will be able to use old and new key to login to servers. You can use new SSH key now on wards, replace old key with new key slowly, there is no rush as both of your keys will work.