Product and Software: This article applies to all Aruba controllers and ArubaOS versions.
From the WebUI Configuration page:
1) Upload a client certificate to the controller. Navigate to Management > Certificates > Upload.
2) Enable SSH authentication using the client public key. Navigate to Management > General.
3) Add a management user. Navigate to Management > Administration > Add User.
On a Linux machine:
1) Copy the client certificate private key to the user's directory ~/.ssh/ folder
2) Change its owner to the user and its access permissions to 600.
3) Optionally rename it to id_rsa.
4) If not renamed, run this command:
ssh -i ~/.ssh//<private key> <username>@<controller IP address>
5) You may be prompted for the private key passcode, if it has been set. Enter it and you will get the controller prompt.