Chapter 9: Ports Menu and Forms 113
2.Click the Access tab. The Access form appears.
3.To restrict access to one or more users or to a group of users, enter previously defined user or group names in the Authorized Users/Groups field, with names separated by commas.
4.To deny access to one or more users or groups, preface the user or group names with an exclamation point (!).
5.Click Done.
6.Click apply changes.
Authentication methods and fallback mechanism
The following table provides a brief description of the authentication methods. When an authentication method is configured to be performed by an authentication server such as Kerberos, LDAP, RADIUS or TACACS+, the user can get access denial if either the authentication server is down or it does not authenticate. An authentication fallback mechanism can be defined in case the first authentication level fails. The following table describes the authentication methods and fallback mechanisms.
Table 9.5: Expert - Authentication Methods and Fallback Mechanisms
Authentication Type | Definition |
None | No authentication. |
Kerberos | Authentication is performed using a Kerberos server. |
Kerberos/Local | Kerberos authentication is tried first, switching to Local if unsuccessful. |
KerberosDownLocal | Local authentication is performed only when the Kerberos server is down. |
LDAP | Authentication is performed against an LDAP database using an LDAP server. |
LDAP/Local | LDAP authentication is tried first, switching to Local if unsuccessful. |
LDAPDownLocal | Local authentication is performed only when the LDAP server is down. |
Local | Authentication is performed locally. For example, using the /etc/passwd file. |
Local/Radius | Authentication is performed locally first, switching to Radius if unsuccessful. |
Local/TACACS+ | Authentication is performed locally first, switching to TACACS+ if unsuccessful. |
Local/NIS | Authentication is performed locally first, switching to NIS if unsuccessful. |
NIS | NIS authentication is performed. |
NIS/Local | NIS authentication is tried first, switching to Local if unsuccessful. |
