To configure SSH, you must first create RSA or DSA keys on each cluster node.

1. Log in as the software owner (in this example, the grid user).
2. To ensure that you are logged in as the grid user, and to verify that the user ID matches the expected user ID you have assigned to the grid user, enter the commands:

   $ id
   $ id grid

   Ensure that Oracle user group and user and the user terminal window process you are using have group and user IDs are identical.

   For example:

   uid=54322(grid) gid=54321(oinstall) groups=54321(oinstall),54322(grid,asmadmin,asmdba) 
   $ id grid uid=54322(grid) gid=54321(oinstall) groups=54321(oinstall),54322(grid,asmadmin,asmdba)

3. If necessary, create the .ssh directory in the grid user's home directory, and set permissions on it to ensure that only the oracle user has read and write permissions:

   $ mkdir ~/.ssh 
   $ chmod 700 ~/.ssh

   Note that the SSH configuration fails if the permissions are not set to 700.
4. Enter the following command:

   $ /usr/bin/ssh-keygen -t dsa

   Note:

   If you have OpenSSH version 7.8 or higher installed on your system, then enter the following command to create SSH keys on each node:

   $ /usr/bin/ssh-keygen -t dsa -m PEM

   At the prompts, accept the default location for the key file (press Enter).

   Never distribute the private key to anyone not authorized to perform Oracle software installations.

   This command writes the DSA public key to the ~/.ssh/id_dsa.pub file and the private key to the ~/.ssh/id_dsa file.
5. Repeat steps 1 through 4 on each node that you intend to make a member of the cluster, using the DSA key.