Multiple SSH Keys

Most of the times we need to create multiple ssh keys in our machine and then configure them. To create ssh-key, run following command

ssh-keygen -t rsa -f filename -b 4096-C "your_email@youremail.com"

In macbook / ubuntu you would already have ssh-keygen lib installed. -t specified the type of key we want to generate. -f specifies the file name, -b specifies the number of bits in the key to create and -C is actually a comment. When you execute above command it asks you to enter a phrase where you must remember for future. Now you have created new ssh key and you can see there will be 2 new files in .ssh folder which will be filename.pub and filename .

Now once you got the files generated you must configure the rsa key in config. So, run command sudo vi ~/.ssh/config and it as shown as below

# Work 
    Host work.github
    HostName github.com
    User git
    PreferredAuthentications publickey
    IdentityFile ~/.ssh/id_rsa_work

# Personal GITHUB
    Host personal.github
    HostName github.com
    User personal_user_name
    PreferredAuthentications publickey
    IdentityFile ~/.ssh/id_rsa_personal

And copy the content from filename.pub and add it in github. So you have loaded you local ssh-key into your github account. Now you can clone / checkout projects of that github account into your local.