Zen FTTP & Opnsense Config (Likely works for Pfsense also)

I've recently migrated from BT FTTP to Zen FTTP. I run Opnsense (and some Unifi access points) connected directly to my ONT.

Whilst I was awaiting activation of my Zen FTTP I was looking around for some reassurance that it would be straightforward to get Opnsense working well and was 99% confident it would be, but couldn't find any conclusive proof so thought I'd put a post here for anyone that might be looking for the same.

Just before activation you receive an email from Zen with your broadband username and broadband password, (this is different to the username and password you use to log in to your account online) and it will take the form:

Username: zenXXXXX@zen
Password: XXXXXXXX
(Click to see screenshot from my email)

Then it's simply a matter of putting that information in the Interfaces:WAN section of your Opnsense configuration.

Link to Basic Configuration

Link to PPPoE Configuration

I don't currently use IPV6 although I believe it needs requesting and activating and I confess I haven't quite got my head confidently enough around the firewall rules to use it yet. If I do so I'll endeavour to update this post.

Hope this helps someone in the same boat as me. I use Opnsense but am familiar with Pfsense and can't see any reason why it wouldn't be incredibly similar in config (if not identical).

Edited by deleted (Tue 20-Sep-22 22:30:45)

Thanks for the guide, I assume this is for Zen via Openreach FTTP?

Does anyone on Zen via Cityfibre FTTP want to add their config guide to this thread (or in a new thread)?

I used opnsense/ dhcpv6 for sometime but have encountered a number of issues where opnsense loses the prefix/wan address for example if the ppoe goes down. I was seeing the same issue with zen when I was on fttc.

Recently I configured static ipv6 using the info zen gave me. Its been absolutely stable since so my recommendation is to use static ipv6 config.

In reply to a post by Aaron_01:

Thanks for the guide, I assume this is for Zen via Openreach FTTP?

Does anyone on Zen via Cityfibre FTTP want to add their config guide to this thread (or in a new thread)?

It is, sorry I ddn't consider there might be a difference between Openreach and Cityfibre. It may well work the same as the generic instructions I saw on Zen's website for "other routers" doesn't indicate a difference between the two.

In reply to a post by choppersrock:

I used opnsense/ dhcpv6 for sometime but have encountered a number of issues where opnsense loses the prefix/wan address for example if the ppoe goes down. I was seeing the same issue with zen when I was on fttc.

Recently I configured static ipv6 using the info zen gave me. Its been absolutely stable since so my recommendation is to use static ipv6 config.

I haven't even looked at IPV6, either how to obtain an address (I believe I need to email Zen) nor how to configure Opnsense to take advantage of this. Any advice and I'm all ears!

I'm on FTTC rather than FTTP, but IPv6 was already enabled on my account but disabled in the FritzBox configuration. I enabled it, and Zen assigned me an IPv6 /48 prefix and we were good to go. I didn't need to contact them at all.

No idea about any of the other stuff though, or how to do it in non-FritzBox equipment though - sorry!

if you contact zen and ask them to enable it they should send you some details.

You can try it using dhcpv6 first once its enabled, then if you want to use it, I would have a go at enabling the static config once they send you some details of your ipv6 address's etc. Static requires a bit more config but the below should be ok for dhcpv6.

for the wan interface.
interfaces,wan, ipv6 type = dhcpv6, apply.

then for the lan side
interfaces, lan, ipv6 type = track interface, apply.

reboot and hopefully you will see the ipv6 addresses under interfaces on the gui,


LAN 1000baseT <full-duplex> 192.168.1.2
2xxxxxxxxxxxxx::

WAN xx.xx.xx.xx
2xxxxxxxxxxxxxxx



Windows etc should then pick up an ipv6 address provided you have enabled it.

I'm not sure about Zen as I chose Giganet over Zen on Cityfibre - but I suspect its the same or similar.

In Giganet's case CityFibre require VLAN ID 911 under the PPPoE connection... So setup a VLAN on the WAN port with VLAN TAG 911, then set the PPPoE interface to use the VLAN interface rather than the WAN interface.

In reply to a post by misstuned:

I'm on FTTC rather than FTTP, but IPv6 was already enabled on my account but disabled in the FritzBox configuration. I enabled it, and Zen assigned me an IPv6 /48 prefix and we were good to go. I didn't need to contact them at all.

Out of interest did your router get a WAN address from within the /48 or a different range (/56 or /64 I forget which) The original set-up was 2 separate blocks. 1 for delegation and 1 for the link.

And was your service a new provision with Zen or an upgrade of an existing service?

I know I'm replying to an old post, but in case anyone else on Zen & Cityfibre comes looking, this worked for me, so thank you philg