Get OpenWRT 5.15 to work on Octaplus networks

CityFibre provides fast, fiberoptic internet to the UK. Octaplus is one of the providers for CityFibre but they didn't make it straight forward for me to set up my own router. The only thing that support told me to do was to:

Tag the VLAN with 911.
Set the username to firstName_lastName.
Set the password to london.

At the time, I was very much new to OpenWRT, and I didn't understand anything (I still don't 100%) about how the system worked. I couldn't get it to work during the support call. However, through trial and error and intense web searching, I managed to do it.

Add a new device configuration

Navigate to: Network -> Interfaces -> Devices (tab)

You should end up around here.

Now, add a new device configuration by clicking the "Add device configuration..." button and net up your new device something like this:

Remember to choose the proper base device that is connected to your ISP's provided box. In this example, that device is eth1. The most important thing is that the VLAN ID tag is 911 and the device type is 802.1q. Every other setting can be left on default. At the time of writing, Octaplus doesn't provide IPv6 addresses, you can disable it if you so choose.

At the end, you can save and create the device and you should end up with something looking like this.

Add the WAN zone

Navigate to: Network -> Interfaces -> Interfaces (tab)

I simply reused the default wan interface that came with OpenWRT. However, you can create a new interface something like this:

Make sure to base it on the eth1.911 device you made previously and select the interface protocol as PPPoE.

After you made your interface or entered the configuration, you will end up with a form asking for details.

The CHAP/PAP username is your name with an underscore between you first and last name. For example, if your name is John Doe the username will be john_doe. The CHAP/PAP password is london.

You might want to ask Octaplus support for your details if your credentials are not working. Their website claims to help you set up your own router, so this should be given to you at the very least.

If you've created your own interface, remember to add it to the firewall.

This is my interface connected successfully with an IP address. Once you set up your interface and save and give it some time, you will see something like this.

Caveats & Troubleshooting

Initially setting up all of these things still didn't make it work straight away. I had to take the following steps.

Octaplus support pointed out that regardless that the service is bound to a mac address. To make it fully work, I simply spoofed my previous device's mac address. To change the mac address, you just have to go into Network -> Interfaces -> Devices (tab) and then click on configure under the device that you need to change the mac address on. This step should only be applicable if you have previously set up your router old and set up OpenWRT on a new device.

You might also need to reset both the router and the termination device. Simply turn the termination device off for around 5 mins, then turn it back on. You can just reboot the OpenWRT instance.

You can also try and call Octaplus as they have some insight onto what is going on at their end. From time to time, they have outages. Sometimes something is configured wrong on their end. Doesn't hurt to try.