FTOS Configuration Guide for the C-Series - Force10 Networks

TACACS+ Remote Authentication and Authorization
FTOS takes the access class from the TACACS+ server. Access class is the class of service that restricts
Telnet access and packet sizes. If you have configured remote authorization, then FTOS ignores the access
class you have configured for the VTY line. FTOS instead gets this access class information from the
TACACS+ server. FTOS needs to know the username and password of the incoming user before it can
fetch the access class from the server. A user, therefore, will at least see the login prompt. If the access
class denies the connection, FTOS closes the Telnet session immediately.
Figure 69 demonstrates how to configure the access-class from a TACACS+ server. This causes the
configured access-class on the VTY line to be ignored. If you have configured a deny10 ACL on the
TACACS+ server, FTOS downloads it and applies it. If the user is found to be coming from the 10.0.0.0
subnet, FTOS also immediately closes the Telnet connection. Note, that no matter where the user is coming
from, they see the login prompt.
Figure 69 Specifying a TACACS+ server host
Force10#
Force10(conf)#
Force10(conf)#ip access-list standard deny10
Force10(conf-ext-nacl)#permit 10.0.0.0/8
Force10(conf-ext-nacl)#deny any
Force10(conf)#
Force10(conf)#aaa authentication login tacacsmethod tacacs+
Force10(conf)#aaa authentication exec tacacsauthorization tacacs+
Force10(conf)#tacacs-server host 25.1.1.2 key force10
Force10(conf)#
Force10(conf)#line vty 0 9
Force10(config-line-vty)#login authentication tacacsmethod
Force10(config-line-vty)#authorization exec tacauthor
Force10(config-line-vty)#
Force10(config-line-vty)#access-class deny10
Force10(config-line-vty)#end
When configuring a TACACS+ server host, you can set different communication parameters, such as the
the key password.
FTOS Configuration Guide, version 7.7.1.0 153