User Authentication.
Configuring 802.1x Port Authentication
Network switches can provide open and easy access to network resources by simply attaching a client PC. Although this automatic configuration and access is a desirable feature, it also allows unauthorized personnel to easily intrude and possibly gain access to sensitive network data.
The IEEE 802.1x (dot1x) standard defines a
This switch uses the Extensible Authentication Protocol over LANs (EAPOL) to exchange
authentication protocol messages with the client, and a remote RADIUS
authentication server to verify user identity and
access rights. When a client (i.e., Supplicant) connects to a switch port,
the switch (i.e., Authenticator) responds with an EAPOL identity request. The client provides its identity (such as a user name) in an EAPOL response to the switch, which it forwards to the RADIUS server. The RADIUS server verifies the client identity and sends an access challenge back to the client. The EAP packet from the RADIUS server contains not only the challenge, but the authentication method to be used. The client can reject the authentication method and request another, depending on the configuration of the client software and the RADIUS server. The authentication method can be MD5, TLS (Transport Layer Security), TTLS (Tunneled Transport Layer Security), or other. The client responds to the appropriate method with its credentials, such as a password or certificate. The RADIUS server verifies the client credentials and responds with an accept or reject packet. If authentication is successful, the switch allows the client to access the network. Otherwise, network access is denied and the port remains blocked.
The operation of 802.1x on the switch requires the following:
•The switch must have an IP address assigned.
•RADIUS authentication must be enabled on the switch and the IP address of the RADIUS server specified.
•Each switch port that will be used must be set to dot1x “Auto” mode.
•Each client that needs to be authenticated must have dot1x client software installed and properly configured.
•The RADIUS server and 802.1x client support EAP. (The switch only supports EAPOL in order to pass the EAP packets from the server to the client.)
•The RADIUS server and client also have to support the same EAP authentication type – MD5, TLS, TTLS, PEAP, etc. (Some clients have native support in Windows, otherwise the dot1x client must support it.)