Dell PowerSwitch S4820T Configuration Guide for the S4820T System 9.14.1.0 - Page 818

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. 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. 818 Security