1-9
To do… Use the command… Remarks
Destroy the RSA key pair public-key local destroy rsa Optional
This task is to create an SSH user and specify an authentication type. Specifying an authentication type
for a new user is a must to get the user login.
An SSH user is represented as a set of user attributes on the SSH server. This set is uniquely identified
with the SSH username. When a user logs in to the SSH server from the SSH client, a username is
required so that the server can looks up the database for matching the username. If a match is found, it
authenticates the user using the authentication mode specified in the attribute set. If not, it tears down
the connection.
To prevent illegal users from logging in to the device, SSH supports the authentication modes of
password, publickey, and password-publickey.
z Password authentication
SSH uses the authentication function of AAA to authenticate the password of the user that is logging in.
Based on the AAA authentication scheme, password authentication can be done locally or remotely. For
local authentication, the SSH server saves the user information and implements the authentication. For
remote authentication, the user information is saved on an authentication server (such as a RADIUS
server) and authentication is implemented through the cooperation of the SSH server and the
authentication server. For AAA details, refer to AAA Operation.
z Publickey authentication
Publickey authentication provides more secure SSH connections than password authentication does.
At present, the device supports RSA for publickey authentication. After configuration, authentication is
implemented automatically without asking you to enter the password. In this mode, you need to create a
key pair on each client, and configure each client's public key on the server. This may be complicated
when multiple SSH clients want to access one SSH server in the network.
z Password-publickey authentication
An SSH user must pass both types of authentication before logging in. In this mode, you do not need to
create a key pair on each client. You can configure the clients to use the same key pair that is created
on one client for publickey authentication. With the AAA function in password authentication, the level of
commands available to a logged-in SSH user is determined by the AAA scheme..
Follow these steps to configure an SSH user and specify an authentication type for the user:
To do... Use the command... Remarks
Enter system view system-view —
ssh authentication-type default
{ all | password |
password-publickey |
publickey }
Specify the default
authentication type for all SSH
users
ssh user username
Use either command.
By default, no SSH user is
created and no authentication
type is specified.
Note that: If both commands