Remote Authentication Dial-In User Service (RADIUS) is a is a networking protocol and management system for users under a particular network. It is a client-server protocol that provides centralized authentication for users connected to the network. The RADIUS protocol provides Authentication, Authorization, and Accounting (AAA) management to users. The RADIUS protocol was first introduced in 1991 by Livingston Enterprises, Inc. as access control and authentication protocol and was later brought into the Internet Engineering Task Force (IETF) standards.
The RADIUS protocol serves three primary functions as follows:
1. Authentication – It authenticates users and devices before allowing them access to the network to protect the network from malicious users.
2. Authorization – It authorizes the users and devices to be able to avail specific network services.
3. Accounting – It accounts for the usage of these services by tracking and recording statistics which can later be used for billing purposes.
Let us discuss the working of the RADIUS protocol. These are the basic steps that a RADIUS protocol follows:
1. The client first tries to authenticate the server using verified user credentials i.e. a username and password combination.
2. The user device sends a request in the form of a message or signal to a Network Access Server (NAS) to gain access to a particular network source. The password is encrypted in the client-server message and is done secretively.
3. The RADIUS server, upon receiving the message from the client, verifies if the message is coming from an authorized user. If the user is identified as unauthorized, the request is deemed illegitimate and denied immediately.
4. If the client is authorized, the RADIUS server reviews and allows the authentication method. Once the authentication method is allowed, the server matches the user credentials against the user database to verify it.
5. The server then checks the profile that the user matches. If no such profile is found, the transaction is ended and user access is denied. If the matching profile is found, an Access-Accept relationship is created between the server and the client to continue the technical authentication process.
6. The client is then authenticated and authorized to gain access to the RADIUS client.
The RADIUS server helps the company to record and maintain the profiles of all users under a centralized database which is accessible to all users under the network. A centralized database approach helps bring the administration to a single point to avoid confusion and boost the performance of the network. This allows efficient server administration and also helps in better security management of the network. It is also quite important in recording network statistics which help in the billing process. RADIUS is an open standard protocol for the AAA framework which can be used by any vendor. It is a protocol in which authentication and authorization are coupled together.
The RADIUS protocol is incredibly flexible and can be used for authentication and authorization purposes for any network. It is a great network protocol to be employed in workspaces with large networks to keep the network safe and also to ensure that there is the optimum usage of the network. It helps to keep unwanted users at bay and record the network usage of authentic users for administration and billing purposes. The RADIUS protocol is one of the best in the market as it an open and scalable network solution, it is flexible and has a very simple client implementation process.