SSH client authentication using a password, SSH client authentication using a public key, and SSH client authentication using a keyboard

For an SSH client, the three types of client authentication.  Two of these client authentication types are complementary rather than mutually exclusive.

• If client authentication using a public key is specified, then the SSH client attempts to do client authentication using a public key.
• If client authentication using a public key is not specified, or if this type of client authentication is tried and fails, then the SSH client attempts to do client authentication using a password.

The keyboard-interactive authentication is enabled on the SSH server side.

When both keyboard interactive and password authentications are enabled, the keyboard-interactive authentication has the priority and the password authentication will not be used.  That is, keyboard-interactive authentication and password authentication are mutually exclusive.

When both keyboard-interactive and public key authentications are enabled, the public key authentication has the priority, but the keyboard-interactive authentication still might be used if the public key authentication failed.  That is, keyboard-interactive authentication and public authentication are complimentary rather than mutually exclusive.