Technical Tip: MAC-based 802.1X authentication

[sselvam]

Description
This article describes how to configure MAC-based 802.1X authentication to managed FortiSwitch ports when using FortiLink.

Solution
Managed FortiSwitch will authenticate and record the MAC addresses of user units.
If there is a hub after the FortiSwitch that connects multiple user units, each unit can access the network after passing authentication.

- The certificates and authentication protocol supported by the supplicant software and RADIUS server are compatible.
- The managed FortiSwitches using FortiLink act as authenticators.

1) Create a firewall policy to allow the RADIUS authentication related traffic from the FortiLink interface to the outbound interface on the FortiGate:

From CLI.

# config firewall policy
    edit <policy_ID>
        set srcintf "fortilink-interface"
        set dstintf "outbound-interface-to-RadiusSVR"
        set srcaddr "all"
        set dstaddr "all"
        set action accept
        set schedule "always"
        set service "RADIUS"
        set nat enable
    next
end

2) Designate a RADIUS server and create a user group.

From CLI.

# config user radius
      edit "Radius1"
         set server "172.18.60.203"
         set secret ENC 1dddddd
     next
end
# config user group
     edit "Radius-Grp1"
        set member "Radius1"
     next
end

From GUI.

- On the FortiGate, go to User & Device -> RADIUS Servers.
- Edit an existing server, or create a new one.
- If necessary, add a Name for the server.
- Set the IP/Name to 172.18.60.203 and Secret to 1dddddd .
- Configure other fields as necessary.
- Select 'OK'.
- Go to User & Device -> User Groups.
- Create a new group, and add the RADIUS server to the Remote Groups list.
- Select 'OK'.

3) Use the new user group in a security policy.

From CLI.

# config switch-controller security-policy 802-1X
    edit "802-1X-policy-default"
        set security-mode 802.1X-mac-based
        set user-group "Radius-Grp1"
        set mac-auth-bypass disable
        set open-auth disable
        set eap-passthru enable
        set guest-vlan disable
        set auth-fail-vlan disable
        set framevid-apply enable
        set radius-timeout-overwrite disable
    next
end

Configure the guest VLAN, authentication fail VLAN, and other parameters as needed.

From GUI.

- Go to Wi-Fi & Switch Controller -> FortiSwitch Security Policies.
- Use the default 802-1X-policy-default, or create a new security policy.
- Use the RADIUS server group in the policy.
- Set the Security mode to MAC-based.
- Configure other fields as necessary.
- Select 'OK'.

4) Apply the security policy to the ports of the managed FortiSwitches.

From CLI.

# config switch-controller  managed-switch
    edit S248EPTF1800XXXX
        # config ports
            edit "port6"      
                set port-security-policy "802-1X-policy-default"
            next
        end
    next
end

On the FortiSwitch, check the configuration.

# config switch interface
    edit "port6"
        set allowed-vlans 4093
        set untagged-vlans 4093
        set security-groups "Radius-Grp1"             
        set snmp-index 6
        # config port-security
            set auth-fail-vlan disable
            set eap-passthru enable
            set framevid-apply enable
            set guest-auth-delay 30
            set guest-vlan disable
            set mac-auth-bypass disable
            set open-auth disable
            set port-security-mode 802.1X-mac-based
            set radius-timeout-overwrite disable
            set auth-fail-vlanid 200
            set guest-vlanid 100
        end
    next
end

From GUI.

- On the FortiGate, go to WiFi & Switch Controller -> FortiSwitch VLANs.
- Configure the VLAN interfaces that are applied on FortiSwitch.
- On FortiGate, these switch VLAN interfaces are treated as layer-3 interfaces and are available to be applied by firewall policy and other security controls in FortiOS. This means that security boundary is extended to FortiSwitch.

Results.

Execute 802.1X authentication on a user unit.

On Linux, run wpa_supplicant.

wpa_supplicant -c /etc/wpa_supplicant/local_supplicant.conf  -D wired -i eth2 -dd
On the FortiGate, view the status of the 802.1X authentication:
diagnose switch-controller switch-info 802.1X
Managed Switch : S248EPTF1800XXXX

   port6 : Mode: mac-based (mac-by-pass disable)               <----- MAC-based.
           Link: Link up
           Port State: authorized: (  )                        <----- Showing authorized means auth passed. Otherwise, shown failed.
           EAP pass-through mode : Enable
           Native Vlan : 1
           Allowed Vlan list: 1,4093
           Untagged Vlan list: 1,4093
           Guest VLAN :
           Auth-Fail Vlan :

           Switch sessions 1/240,     Local port sessions:1/20
           Client    MAC          Type    Vlan  Dynamic-Vlan
           00:0c:29:d4:4f:3c     802.1x      1      0           <----- User unit of auth passed can access the network. Its MAC address is recored, while other User units under same FSW ports still not allowed to access.

           Sessions info:
           00:0c:29:d4:4f:3c     Type=802.1x,MD5,state=AUTHENTICATED,etime=6,eap_cnt=3 params:reAuth=3600