Enhancing Network Security with 802.1X Authentication

A Cisco Protocol Overview

The 802.1X standard is a method for authentication to prevent unauthorized access to switch ports. Until a user is authenticated, traffic other than Extensible Authentication Protocol Over LAN (EAPOL) is not permitted through the switch port. This capability is also used to control wireless access.

Understanding Switch Port States under 802.1X Protocol:

• Force-Authorized: This is the default state for ports where the 802.1X protocol is not enabled.
• Force-Unauthorized: This state applies to ports where the protocol is enabled. In this state, traffic except for authentication traffic is blocked, and when authentication is successful, the port moves to the authorized state.

Configuration Steps:

Firstly, the RADIUS Server needs to be configured:

Switch(config)#aaa new-model

Next, the user authentication method for the 802.1X protocol based on RADIUS will be set up:

Switch(config)#aaa authentication dot1x radius group default

In the subsequent step, the address and necessary information for the Radius Server are established:

Switch(config)#radius-server host [RADIUS-Server-IPAddress] key [Secret-Key]
Switch(config)#radius-server host [RADIUS-Server-IP-Address] auth port 1812

To activate the protocol on the switch:

Switch(config)#dot1x system-auth-control

To enable 802.1X authentication on switch ports:

Switch(config-if)#dot1x portcontrol auto

These configurations establish the foundation for implementing the 802.1X standard for user authentication, ensuring secure access to switch ports and enhancing network security against unauthorized access attempts.