Brocade Communications Systems Brocade ICX 6650 6650 - Manual (Page 90)

70 Brocade ICX 6650 Security Configuration Guide
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Optional SSH parameters
• Whether the Brocade device allows users to log in without supplying a password
• The port number for SSH connections
• The SSH login timeout value
• A specific interface to be used as the source for all SSH traffic from the device
• The maximum idle time for SSH sessions
Setting the number of SSH authentication retries
By default, the Brocade device attempts to negotiate a connection with the connecting host three
times. The number of authentication retries can be changed to between 1–5.
For example, the following command changes the number of authentication retries to 5.
Brocade(config)# ip ssh authentication-retries 5
Syntax: ip ssh authentication-retries number
Deactivating user authentication
After the SSH server on the Brocade device negotiates a session key and encryption method with
the connecting client, user authentication takes place. The Brocade implementation of SSH
supports DSA or RSA challenge-response authentication and password authentication.
With DSA or RSA challenge-response authentication, a collection of clients’ public keys are stored
on the Brocade device. Clients are authenticated using these stored public keys. Only clients that
have a private key that corresponds to one of the stored public keys can gain access to the device
using SSH.
With password authentication, users are prompted for a password when they attempt to log into the
device (provided empty password logins are not allowed). If there is no user account that matches
the user name and password supplied by the user, the user is not granted access.
You can deactivate one or both user authentication methods for SSH. Note that deactivating both
authentication methods essentially disables the SSH server entirely.
To disable DSA or RSA challenge-response authentication, enter the following command.
Brocade(config)# ip ssh key-authentication no
Syntax: ip ssh key-authentication yes | no
The default is yes.
To deactivate password authentication, enter the following command.
Brocade(config)# ip ssh password-authentication no
Syntax: ip ssh password-authentication no | yes
The default is yes.