Example: Configuring MAC RADIUS Authentication on an EX Series Switch

Requirements

• Junos OS Release 9.3 or later for EX Series switches.
• An EX Series switch acting as an authenticator port access entity (PAE). The ports on the authenticator PAE form a control gate that blocks all traffic to and from supplicants until they are authenticated.
• A RADIUS authentication server. The authentication server acts as the backend database and contains credential information for hosts (supplicants) that have permission to connect to the network.

Before you configure MAC RADIUS authentication, be sure you have:

• Configured basic access between the EX Series switch and the RADIUS server. See Example: Connecting a RADIUS Server for 802.1X to an EX Series Switch.
• Performed basic bridging and VLAN configuration on the switch. See Example: Setting Up Basic Bridging and a VLAN for an EX Series Switch.
• Performed basic 802.1X configuration. See Configuring 802.1X Interface Settings (CLI Procedure).

Overview and Topology

IEEE 802.1X Port-Based Network Access Control (PNAC) authenticates and permits devices access to a LAN if the devices can communicate with the switch using the 802.1X protocol (are 802.1X-enabled). To permit non-802.1X-enabled end devices to access the LAN, you can configure MAC RADIUS authentication on the interfaces to which the end devices are connected. When the MAC address of the end device appears on the interface, the switch consults the RADIUS server to check whether it is a permitted MAC address. If the MAC address of the end device is configured as permitted on the RADIUS server, the switch opens LAN access to the end device.

You can configure both MAC RADIUS authentication and 802.1X authentication methods on an interface configured for multiple supplicants. Additionally, if an interface is only connected to a non-802.1X-enabled host, you can enable MAC RADIUS and not enable 802.1X authentication using the mac-radius restrict option, and thus avoid the delay that occurs while the switch determines that the device is does not respond to EAP messages.

Figure 1 shows the two printers connected to the switch.

Figure 1: Topology for MAC RADIUS Authentication Configuration

Table 1 shows the components in the example for MAC RADIUS authentication.

The printer with the MAC address 00040ffdacfe is connected to access interface ge-0/0/19. A second printer with the MAC address 0004aecd235f is connected to access interface ge-0/0/20. In this example, both interfaces are configured for MAC RADIUS authentication on the switch, and the MAC addresses (without colons) of both printers are configured on the RADIUS server. Interface ge-0/0/20 is configured to eliminate the normal delay while the switch attempts 802.1X authentication; MAC RADIUS authentication is enabled and 802.1X authentication is disabled using the mac-radius restrict option.

Configuration

To configure MAC RADIUS authentication on the switch, perform these tasks:

CLI Quick Configuration

To quickly configure MAC RADIUS authentication, copy the following commands and paste them into the switch terminal window:

Note: You must also configure the two MAC addresses as usernames and passwords on the RADIUS server, as is done in step 2 of the Step-by-Step Procedure.

Step-by-Step Procedure

1. On the switch, configure the interfaces to which the printers are attached for MAC RADIUS authentication, and configure the restrict option on interface ge-0/0/20, so that only MAC RADIUS authentication is used:
   [edit]
user@switch# set protocols dot1x authenticator interface ge-0/0/19 mac-radius
user@switch# set protocols dot1x authenticator interface ge-0/0/20 mac-radius restrict

2. On the RADIUS server, configure the MAC addresses 00040ffdacfe and 0004aecd235f as usernames and passwords:
   [root@freeradius]#
edit /etc/raddb
vi users
00040ffdacfe Auth-type:=EAP, User-Password = "00040ffdacfe"
0004aecd235f Auth-type:=EAP, User-Password = "0004aecd235f"

Results

Display the results of the configuration on the switch:

Verification

Verify that the supplicants are authenticated:

• Verifying That the Supplicants Are Authenticated

Verifying That the Supplicants Are Authenticated

Purpose

After supplicants are configured for MAC RADIUS authentication on the switch and on the RADIUS server, verify that they are authenticated and display the method of authentication:

Action

ge-0/0/19.0
  Role: Authenticator
  Administrative state: Auto
  Supplicant mode: Single
  Number of retries: 3
  Quiet period: 60 seconds
  Transmit period: 30 seconds
  Mac Radius: Enabled
  Mac Radius Restrict: Disabled
  Reauthentication: Enabled
  Configured Reauthentication interval: 3600 seconds
  Supplicant timeout: 30 seconds
  Server timeout: 30 seconds
  Maximum EAPOL requests: 2
  Guest VLAN member: <not configured>
  Number of connected supplicants: 1
    Supplicant: user101, 00:04:0f:fd:ac:fe
      Operational state: Authenticated
      Authentication method: Radius
      Authenticated VLAN: vo11
      Dynamic Filter: match source-dot1q-tag 10 action deny
      Session Reauth interval: 60 seconds
      Reauthentication due in 50 seconds

ge-0/0/20.0
  Role: Authenticator
  Administrative state: Auto
  Supplicant mode: Single
  Number of retries: 3
  Quiet period: 60 seconds
  Transmit period: 30 seconds
  Mac Radius: Enabled
  Mac Radius Restrict: Enabled
  Reauthentication: Enabled
  Configured Reauthentication interval: 3600 seconds
  Supplicant timeout: 30 seconds
  Server timeout: 30 seconds
  Maximum EAPOL requests: 2
  Guest VLAN member: <not configured>
  Number of connected supplicants: 1
    Supplicant: user102, 00:04:ae:cd:23:5f
      Operational state: Authenticated
      Authentcation method: Radius
      Authenticated VLAN: vo11
      Dynamic Filter: match source-dot1q-tag 10 action deny
      Session Reauth interval: 60 seconds
      Reauthentication due in 50 seconds

Meaning

The sample output from the show dot1x interface detail command displays the MAC address of the connected end device in the Supplicant field. On interface ge-0/0/19, the MAC address is 00:04:0f:fd:ac:fe, which is the MAC address of the first printer configured for MAC RADIUS authentication. The Authentication method field displays the authentication method as MAC Radius. On interface ge-0/0/20, the MAC address is 00:04:ae:cd:23:5f, which is the MAC address of the second printer configured for MAC RADIUS authentication. The Authentication method field displays the authentication method as MAC Radius.