Glossary

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.
Configure local authentication globally and configure access classes on a per-user basis.
can assign different access classes to different users by username. Until users attempt to log in, 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, retrieves the access class from the local database and applies
it. ( then can 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
configure 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 configured for the VTY line. It defaults from the local database.
Example of Configuring VTY Authorization Based on Access Class Retrieved from a Local Database (Per User)
DellEMC(conf)#user gooduser password abc privilege 10 access-class permitall
DellEMC(conf)#user baduser password abc privilege 10 access-class denyall
DellEMC(conf)#
DellEMC(conf)#aaa authentication login localmethod local
DellEMC(conf)#
DellEMC(conf)#line vty 0 9
DellEMC(config-line-vty)#login authentication localmethod
DellEMC(config-line-vty)#end
VTY Line Remote Authentication and Authorization
retrieves the access class from the VTY line.
The takes the access class from the VTY line and applies it to ALL users. 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 configured an access class for the VTY line, immediately applies it. If the access-class is set to deny all or deny for
the incoming subnet, 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 Configuring VTY Authorization Based on Access Class Retrieved from the Line (Per Network Address)
DellEMC(conf)#ip access-list standard deny10
DellEMC(conf-ext-nacl)#permit 10.0.0.0/8
DellEMC(conf-ext-nacl)#deny any
DellEMC(conf)#
DellEMC(conf)#aaa authentication login tacacsmethod tacacs+
DellEMC(conf)#tacacs-server host 256.1.1.2 key Force10
DellEMC(conf)#
DellEMC(conf)#line vty 0 9
DellEMC(config-line-vty)#login authentication tacacsmethod
DellEMC(config-line-vty)#
DellEMC(config-line-vty)#access-class deny10
DellEMC(config-line-vty)#end
(same applies for radius and line authentication)
VTY MAC-SA Filter Support
supports MAC access lists which permit or deny users based on their source MAC address.
With this approach, you can implement a security policy based on the source MAC address.
To apply a MAC ACL on a VTY line, use the same access-class command as IP ACLs.
The following example shows how to deny incoming connections from subnet 10.0.0.0 without displaying a login prompt.
Security
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