How RADIUS/802.1X authentication affects VLAN operation

Static VLAN requirement:

RADIUS authentication for an 802.1X client on a given port can include a (static) VLAN requirement. (Refer to the documentation provided with your RADIUS application.) The static VLAN to which a RADIUS server assigns a client must exist on the switch. If it does not exist or is a dynamic VLAN (created by GVRP), authentication fails. Also, for the session to proceed, the port must be an untagged member of the required VLAN. If it is not, the switch temporarily reassigns the port.

If the port used by the client is not configured as an untagged member of the required static VLAN:

When a client is authenticated on port “N”, if port “N” is not already configured as an untagged member of the static VLAN specified by the RADIUS server, then the switch temporarily assigns port “N” as an untagged member of the required VLAN (for the duration of the 802.1X session). At the same time, if port “N” is already configured as an untagged member of another VLAN, port “N” loses access to that other VLAN for the duration of the session. (This loss of access occurs because a port can be an untagged member of only one VLAN at a time.)

Using a RADIUS server to authenticate clients, you can provide port-level security protection from unauthorized network access for the following authentication methods:

  • 802.1X: Port-based or client-based access control to open a port for client access after authenticating valid user credentials.

  • MAC address: Authenticates a device MAC address to grant access to the network

  • WebAgent: Authenticates clients for network access using a webpage for user login.


You can use 802.1X (port-based or client-based) authentication and either Web or MAC authentication at the same time on a port, with a maximum of 32 clients allowed on the port. (The default is one client.) Web authentication and MAC authentication are mutually exclusive on the same port. Also, you must disable LACP on ports configured for any of these authentication methods.