RADIUS/
TACACS+ server
1. Client attempts management access.
2. Switch contacts authentication server.
3. Authentication server challenges client.
4. Client responds with proper password or key.
5. Authentication server approves access.
6. Switch grants management access.
Web
Telnet
console

3 Configuring the Switch

Configuring Local/Remote Logon Authentication

Use the Authentication Settings menu to restrict management access based on specified user names and passwords. You can manually configure access rights on the switch, or you can use a remote access authentication server based on RADIUS or TACACS+ protocols.

Remote Authentication Dial-in

User Service (RADIUS) and Terminal Access Controller Access Control System Plus (TACACS+) are logon

authentication protocols that use software running on a central

server to control access to RADIUS-aware or TACACS-

aware devices on the network. An authentication server contains

a database of multiple user name/password pairs with associated privilege levels for each user that requires management access to the switch.

RADIUS uses UDP while TACACS+ uses TCP. UDP only offers best effort delivery, while TCP offers a connection-oriented transport. Also, note that RADIUS encrypts only the password in the access-request packet from the client to the server, while TACACS+ encrypts the entire body of the packet.

Command Usage

•By default, management access is always checked against the authentication database stored on the local switch. If a remote authentication server is used, you must specify the authentication sequence and the corresponding parameters for the remote authentication protocol. Local and remote logon authentication control management access via the console port, web browser, or Telnet.

•RADIUS and TACACS+ logon authentication assign a specific privilege level for each user name/password pair. The user name, password, and privilege level must be configured on the authentication server.

•You can specify up to three authentication methods for any user to indicate the authentication sequence. For example, if you select (1) RADIUS, (2) TACACS and

(3) Local, the user name and password on the RADIUS server is verified first. If the RADIUS server is not available, then authentication is attempted using the TACACS+ server, and finally the local user name and password is checked.

Command Attributes

•Authentication – Select the authentication, or authentication sequence required:

-Local – User authentication is performed only locally by the switch.

-Radius – User authentication is performed using a RADIUS server only.

-TACACS – User authentication is performed using a TACACS+ server only.

-[authentication sequence] – User authentication is performed by up to three authentication methods in the indicated sequence.

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