Administrator Guide

The system provides several ways to congure access classes for VTY lines, including:
VTY Line Local Authentication and Authorization
VTY Line Remote Authentication and Authorization
VTY Line Local Authentication and Authorization
The system retrieves the access class from the local database.
To use this feature:
1 Create a username.
2 Enter a password.
3 Assign an access class.
4 Enter a privilege level.
You can assign line authentication on a per-VTY basis; it is a simple password authentication, using an access-class as authorization.
Congure local authentication globally and congure access classes on a per-user basis.
The system can assign dierent access classes to dierent users by username. Until users attempt to log in, the system does not know if
they will be assigned a VTY line. This means that incoming users always see a login prompt even if you have excluded them from the VTY
line with a deny-all access class. After users identify themselves, the system retrieves the access class from the local database and applies
it. (The system can then close the connection if a user is denied access.)
NOTE
: If a VTY user logs in with RADIUS authentication, the privilege level is applied from the RADIUS server only if you
congure RADIUS authentication.
The following example shows how to allow or deny a Telnet connection to a user. Users see a login prompt even if they cannot log in. No
access class is congured for the VTY line. It defaults from the local database.
NOTE
: For more information, refer to Access Control Lists (ACLs).
Example of Conguring VTY Authorization Based on Access Class Retrieved from a Local Database (Per User)
Dell(conf)#user gooduser password abc privilege 10 access-class permitall
Dell(conf)#user baduser password abc privilege 10 access-class denyall
Dell(conf)#
Dell(conf)#aaa authentication login localmethod local
Dell(conf)#
Dell(conf)#line vty 0 9
Dell(config-line-vty)#login authentication localmethod
Dell(config-line-vty)#end
VTY Line Remote Authentication and Authorization
The system retrieves the access class from the VTY line.
The Dell Networking OS takes the access class from the VTY line and applies it to ALL users. The system does not need to know the
identity of the incoming user and can immediately apply the access class. If the authentication method is RADIUS, TACACS+, or line, and
you have congured an access class for the VTY line, the system immediately applies it. If the access-class is set to deny all or deny for the
incoming subnet, the system closes the connection without displaying the login prompt. The following example shows how to deny
incoming connections from subnet 10.0.0.0 without displaying a login prompt. The example uses TACACS+ as the authentication
mechanism.
Example of Conguring VTY Authorization Based on Access Class Retrieved from the Line (Per Network Address)
Dell(conf)#ip access-list standard deny10
Dell(conf-ext-nacl)#permit 10.0.0.0/8
Dell(conf-ext-nacl)#deny any
Security
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