In this tutorial, I will demonstrate how to configure OPNsense with Freedom Internet (a Dutch internet provider that originated from XS4ALL). We will do more than just setting up internet access; we will also ensure IPv6 is working correctly and that the MTU is configured correctly.
Open the web interface and go to Interfaces -> Assignments, and make sure you have assigned the physical WAN interface to your router:
Enable interface: <check>
Prevent interface removal: <check>
Block private networks and loopback addresses: <Uncheck>
Block bogon networks: <Uncheck>
IPv4 Configuration type: <none>
IPv6 Configuration type: <none>
MTU: 1512
MSS: <empty>
Note: We have an MTU of 1512 at this interface because we are using a VLAN (+4) and PPPoE (+8) and we want 1500 at the IP level.
Now go to Interfaces -> Other Types -> VLAN and press + to add a new VLAN :
Device: vlan06
Parent interface: ix1 (choose the WAN interface we just created)
VLAN Tag: 6
VLAN Priority: [default]
Description: Freedom Internet Vlan
Now head back to Interfaces -> Assignments and you will see the newly created VLAN you just created. Add it as a new interface (it will probably show up as OPTx) and edit it.
Note: I am showing only the options that are relevant in the screenshot; you will see more options when you edit the interface.
Enable interface: <check>
Description: Freedom
Block private networks and loopback addresses: <Check>
Block bogon networks: <Check>
IPv4 Configuration type: <PPPoE>
IPv6 Configuration type: <DHCP6>
MTU: <empty>
MSS: <empty>
PPPoE Configuration:
Username: fake@freedom.nl
Password: 1234
Dial on demand: <uncheck>
Idle timeout: <empty>
DHCP6 Client configuration
Request only an IPv6 prefix: <check>
DHCPv6 Prefix Delegation size: 48
Send IPv6 prefix hint: <check>
Use IPv4 connectivity: <check>
Use VLAN priority: <Disabled>
Now head to the PPPoE interface you created in the previous step: Interfaces -> Point-to-Point -> Devices and edit the pppoe0 interface. Click on 'Show advanced options' and add a 1508 MTU.
Now you can apply all settings, and I recommend that you reboot your OPNsense instance. After we did this we are now going to check if we have the correct MTU, visit Speedguide.net TCP/IP Analyzer
The result should be:
Now let's check if IPv6 is configured correctly, visit Test IPv6
The result should be:
All done! Enjoy your fast internet 🙂
