Setting up and configuring 802.1X Open VLAN mode

Preparation:

This section assumes use of both the unauthorized-client and authorized-client VLANs.

Before you configure the 802.1X Open VLAN mode on a port:
  • Statically configure an Unauthorized-Client VLAN in the switch. The only ports that should belong to this VLAN are ports offering services and access you want available to unauthenticated clients. (802.1X authenticator ports do not have to be members of this VLAN.)
    CAUTION:

    Do not allow any port memberships or network services on this VLAN that would pose a security risk if exposed to an unauthorized client.

  • Statically configure an Authorized-Client VLAN in the switch. The only ports that should belong to this VLAN are ports offering services and access you want available to authenticated clients. 802.1X authenticator ports do not have to be members of this VLAN.Note that if an 802.1X authenticator port is an untagged member of another VLAN, the port’s access to that other VLAN will be temporarily removed while an authenticated client is connected to the port.For example, if:

    1. Port 5 is an untagged member of VLAN 1 (the default VLAN).

    2. You configure port 5 as an 802.1X authenticator port.

    3. You configure port 5 to use an Authorized-Client VLAN.

    Then, if a client connects to port 5 and is authenticated, port 5 becomes an untagged member of the Authorized-Client VLAN and is temporarily suspended from membership in the default VLAN.

  • If you expect friendly clients to connect without having 802.1X supplicant software running, provide a server on the Unauthorized-Client VLAN for downloading 802.1X supplicant software to the client, and a procedure by which the client initiates the download.

  • A client must either have a valid IP address configured before connecting to the switch, or download one through the Unauthorized-Client VLAN from a DHCP server. In the latter case, you will need to provide DHCP services on the Unauthorized-Client VLAN.

  • Ensure that the switch is connected to a RADIUS server configured to support authentication requests from clients using ports configured as 802.1X authenticators. (The RADIUS server should not be on the Unauthorized-Client VLAN.)
    NOTE:

    As an alternative, you can configure the switch to use local password authentication instead of RADIUS authentication. However, this is less desirable because it means that all clients use the same passwords and have the same access privileges. Also, you must use 802.1X supplicant software that supports the use of local switch passwords.

    CAUTION:

    Ensure that you do not introduce a security risk by allowing Unauthorized- Client VLAN access to network services or resources that could be compromised by an unauthorized client.