Dell N3200-ON Networking N-Series Switches User Guide version 6.8.0 - Page 257

DACL IP-DACL-IN00000018 Redirect ACL Redirect URL Acct SessionId testUser:a00000018 Linksec policy should-secure Using RADIUS The RADIUS client on the switch supports multiple RADIUS servers. When multiple authentication servers are configured, they can help provide redundancy. One server can be designated as the primary and the other(s) will function as backup server(s). The switch attempts to use the primary server first. if the primary server does not respond, the switch attempts to use the backup servers. A priority value can be configured to determine the order in which the backup servers are contacted. How Does RADIUS Control Management Access? Many networks use a RADIUS server to maintain a centralized user database that contains per-user authentication information. RADIUS servers provide a centralized authentication method for: • Network Access (IEEE 802.1X) • User Manager (Management access) • Captive Portal Like TACACS+, RADIUS access control utilizes a database of user information on a remote server. Making use of a single database of accessible information-as in an Authentication Server-can greatly simplify the authentication and management of users in a large network. One such type of Authentication Server supports the Remote Authentication Dial In User Service (RADIUS) protocol as defined by RFC 2865. For authenticating users, the RADIUS standard has become the protocol of choice by administrators of large networks. To accomplish the authentication in a secure manner, the RADIUS client and RADIUS server must both be configured with the same shared password or "secret". This "secret" is used to generate one-way encrypted authenticators that are present in all RADIUS packets. The "secret" is never transmitted over the network. Authentication, Authorization, and Accounting 257