Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 840

TACACS+ Remote Authentication and Authorization The system 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, the system ignores the access class you have configured for the VTY line and gets this access class information from the TACACS+ server. The system must know the username and password of the incoming user before it can fetch the access class from the server. A user, therefore, at least sees the login prompt. If the access class denies the connection, the system closes the Telnet session immediately. The following example demonstrates how to configure the access-class from a TACACS+ server. This configuration ignores the configured access-class on the VTY line. If you have configured a deny10 ACL on the TACACS+ server, the system downloads it and applies it. If the user is found to be coming from the 10.0.0.0 subnet, the system also immediately closes the Telnet connection. Note, that no matter where the user is coming from, they see the login prompt. When configuring a TACACS+ server host, you can set different communication parameters, such as the key password. Example of Specifying a TACACS+ Server Host Dell# Dell(conf)# Dell(conf)#ip access-list standard deny10 Dell(conf-std-nacl)#permit 10.0.0.0/8 Dell(conf-std-nacl)#deny any Dell(conf)# Dell(conf)#aaa authentication login tacacsmethod tacacs+ Dell(conf)#aaa authentication exec tacacsauthorization tacacs+ Dell(conf)#tacacs-server host 25.1.1.2 key Force10 Dell(conf)# Dell(conf)#line vty 0 9 Dell(config-line-vty)#login authentication tacacsmethod Dell(config-line-vty)#authorization exec tacauthor Dell(config-line-vty)# Dell(config-line-vty)#access-class deny10 Dell(config-line-vty)#end Specifying a TACACS+ Server Host To specify a TACACS+ server host and configure its communication parameters, use the following command. • Enter the host name or IP address of the TACACS+ server host. CONFIGURATION mode tacacs-server host {hostname | ip-address} [port port-number] [timeout seconds] [key key] Configure the optional communication parameters for the specific host: - port port-number: the range is from 0 to 65335. Enter a TCP port number. The default is 49. - timeout seconds: the range is from 0 to 1000. Default is 10 seconds. - key key: enter a string for the key. The key can be up to 42 characters long. This key must match a key configured on the TACACS+ server host. This parameter must be the last parameter you configure. If you do not configure these optional parameters, the default global values are applied. Example of Connecting with a TACACS+ Server Host To specify multiple TACACS+ server hosts, configure the tacacs-server host command multiple times. If you configure multiple TACACS+ server hosts, the system attempts to connect with them in the order in which they were configured. To view the TACACS+ configuration, use the show running-config tacacs+ command in EXEC Privilege mode. To delete a TACACS+ server host, use the no tacacs-server host {hostname | ip-address} command. Security 840