FTTP with Zen and Cityfibre - Asus AX88u and AX86u

Hello, I hope someone out there with the necessary technical knowledge can help. I recently upgraded to Zen's FTTP network which is installed and run by Cityfibre. It's an asynchronous 900Mb connection and I am using the supplied 7530 Fritz!box. Prior to that I was also with Zen on ADSL using my own equipment - An Asus RT-AX88U and a DrayTek Vigor130 modem. Theoretically I can just connect my ASUS to the Callix ONT and everything should work. That is not the case. No matter what settings I use - PPPoE, static IP, automatic ip etc, setting the VLAN to the figure in my Zen portal, cloning the 7530 MAC, using the built in wizards - the connection either fails to sync, syncs with some errors or syncs and then won't route. Zen are no help at all as they don't support 3rd party equipment but they have assured me they are not stopping anyone from using their own equipment. I have tried with both the routers mentioned in the subject. The 88u is running the latest merlin firmware and the 86u is running stock. I can post logs from the 88u if needed - The 86u was borrowed to see if it would work. The Wifi signal from the 7530 just isn't up to the job in my house and I'm not prepared to pay Zen extra just to get a better router when I've already got one that's more than up to the task. Also it is not possible to configure the 7530 as a modem only and to then use the 88u as a router.

Hope someone can help. Thanks in advance for reading.

How are you setting the VLAN on the Asus?

Reading instructions for another CityGibre ISP you need to go to: LAN > IPTV tab select the "manual" profile and set the VLAN ID to 911

Looks like this on my ax86u running Merlin.

Edited by j0hn83 (Sun 19-Sep-21 01:10:27)

Thanks, that's exactly how it looks on mine. Zen said the VLAN is 70 and that doesn't work either. I've also tried 101.

Try 911 , or you've tried that already? No idea then sorry.

Edited by j0hn83 (Sun 19-Sep-21 02:39:36)

What do the logs on the router say?

As a stop-gap while you try and get the Asus working is it possible to leave the network/DHCP stuff to the Fritzbox but turn the WiFi off on that and use the Asus as a WAP?

In reply to a post by Ax88u_Ax86u:

It's an asynchronous 900Mb connection

You mean symmetric?

You could capture the packets between the Zen Fritz!box router's WAN port and the ONT by putting a switch in between with a mirror port, and using wireshark/tcpdump to capture packets. Then you'd be able to see the PPPoE packets and their VLAN tags, then configure the Asus to match. Assuming you had access to such a switch.

You could also rule out problems with Asus firmware by plugging a PC/laptop directly into the ONT, configuring PPPoE with a VLAN tag, and see if you can bring the link up that way.

However, a much simpler solution would be to keep the FB router for routing, and use your Asus just as a wireless access point. You'd need to disable the DHCP server on the Asus, then connect its LAN side to a LAN port on the FB. If you wish, you could then disable wireless on the FB entirely.

In reply to a post by Ax88u_Ax86u:

Also it is not possible to configure the 7530 as a modem only and to then use the 88u as a router

This wouldn't apply to FTTP anyway. The ONT is the "modem", performing essentially the same job as your Draytek Vigor130 did for your ADSL setup. Both of them present Ethernet to the router.

Thanks for the reply. If that's the correct term then yes (same speed up and down). I do have a switch so I'll try that suggestion sometime this week when I've got spare time and if that doesn't help I'll try the other options.

Thanks for the reply and yes I'm going to try that in the meantime.

Thanks but yes I've tried that already.

In reply to a post by Ax88u_Ax86u:

I do have a switch so I'll try that suggestion sometime this week when I've got spare time and if that doesn't help I'll try the other options.

Great. It'll need to be a switch with an admin UI; you should be able to configure it so that all traffic entering through ports 1 and 2 (say) has an extra copy sent out of port 3. That function may be called "mirror port" or "span port" depending on the vendor - but not "spanning tree", as that's something completely different!

In reply to a post by candlerb:

You could also rule out problems with Asus firmware by plugging a PC/laptop directly into the ONT, configuring PPPoE with a VLAN tag, and see if you can bring the link up that way.

Would presumably be a heck of lot faster and easier to quickly check the correct PPPoE and VLAN id is set in this way.

If that doesn’t work then there’s a problem that could be resolved without resorting to extra switches, packet sniffing etc. etc.

This is a log from today using Zen supplied credentials which for the record (minus my IP) are:

IP - xx.xx.xx.xx
Subnet mask - 255.255.255.255
DNS1 - 212.23.3.100
DNS2 - 212.23.6.100
No gateway supplied but ascertained as - 51.148.77.180 - using FritzBox logs and traceroute
VLAN - 70

Forum won't allow me to post the log.

Router Log

The results are exactly the same whatever VLAN I set.

I see no evidence of any PPPoE connection attempt there.

You can ignore the multicast DNS (avahi) and lldp stuff on the WAN port - Zen will ignore all these packets.

What about 802.1p? I have to set this parameter for VDSL.

Doesn’t look like it.

Your suggestion of using a laptop to connect direct to the ONT, should instantly prove/disprove the PPPoE credentials and correct VLAN id is all set correctly.

Sorry wrong log, that one was with static ip setup. This one is with PPPoE. The only method which doesn't result in a red light on the router is static ip setup btw. Log is from stopped service after reboot and then turning back on.

Zen VLAN 911

In reply to a post by Ax88u_Ax86u:

Sorry wrong log, that one was with static ip setup. This one is with PPPoE. The only method which doesn't result in a red light on the router is static ip setup btw. Log is from stopped service after reboot and then turning back on.

Zen VLAN 911

Looks like you’ve got a PPPoE issue there.

Logs from when you're trying PPPoE may be of more interest (red light or not). They'll show whether the PPPoE discovery (PADI) is working, and whether you get as far as trying to authenticate.

Does your router support sending PPPoE *with* VLAN tagging enabled?

In the log snippet, looks like the PPP daemon starts but there are two timeouts for PADO response shown in the posted log above. I haven’t mucked in with PPPoE troubleshooting but that looks like a miscommunication between router and ISP.

The laptop method would at least prove he’s on the right track with basic settings for PPPoE creds and the correct VLAN.

I believe this router has been successfully used on the CityFibre network but with Vodafone on a different VLAN to that used by OP. So it should theoretically work with Zen on the same net?

That log is from boot up - there are no other entries.

As for pppoe with vlan tagging I'm beginning to think that it the 88u doesn't support it. It has an IPTV vlan option but there is nothing in the pppoe settings for vlan tagging. Zen actually say vlan should be 0 to start and cityfibre set it to 911 afterwards. I have noticed from the fb router logs than whenever I turn it off it has a log entry "the service provider successfully transmitted settings to this device" just after the pppoe connection succeeds. There is also an option for vlan in the fb pppoe settings which allows an entry of 0. IPTV settings on the 88u do not allow 0.

Might be time time look for a new router.

They likely don't allow 0 because they don't need to. VLAN 0 is the default VLAN (i.e no VLAN) so you shouldn't need to specify it. The thing that's probably failing is the "set it to 911".

I'd be considering instead going for dedicated WAPs.
Separating the traffic routing from WiFi provision makes things a bit easier to manage at home.

In reply to a post by aidanh:

They likely don't allow 0 because they don't need to. VLAN 0 is the default VLAN (i.e no VLAN) so you shouldn't need to specify it.

From what I gather, there are some providers who require you to include the 802.1p/q header (2 bytes) with the VLAN bits set to zero. It's a bit funky, but there you go.

It's what you do to send "untagged" packets with the 802.1p priority bits. This is different from the "default" VLAN, which is VLAN ID 1 on every switch I have come across.

In reply to a post by Ax88u_Ax86u:

Zen actually say vlan should be 0 to start and cityfibre set it to 911 afterwards

Potentially for the initial autoprovisioning if that is supported on CityFibre, otherwise complete tosh - there is no mechanism to just change VLANs in the PPPoE link control protocol (LCP) or network control protocols (NCP).

I have noticed from the fb router logs than whenever I turn it off it has a log entry "the service provider successfully transmitted settings to this device" just after the pppoe connection succeeds

That is likely the client IP and DNS server IP addresses which are sent as part of the internet protocol control protocol (IPCP) (one of the network control protocols) negotiation.

It is a pity Zen don't just have a list of the required protocols in their support pages, the "fibre" examples are at least 5 years old and mostly relate to FTTC, and there is nothing for IPv6.

In reply to a post by candlerb:

From what I gather, there are some providers who require you to include the 802.1p/q header (2 bytes) with the VLAN bits set to zero. It's a bit funky, but there you go.

It's what you do to send "untagged" packets with the 802.1p priority bits.

It appears to be more common in the US where some large providers require you to make the initial DHCP request untagged but with a specific priority, there seems no particular reason other than making it more difficult to use your own equipment - they typically rent you their router, so a nice little earner.

Openreach do support priority-only packets on ingress so you can mark higher-priority traffic, e.g. VoIP, but only between the client router and Cablelink handover. See SIN506 issue 1.9, section 2.3.9

In reply to a post by tdw42:

It is a pity Zen don't just have a list of the required protocols in their support pages, the "fibre" examples are at least 5 years old and mostly relate to FTTC, and there is nothing for IPv6.

Does the OP actually know which is the correct VLAN for Zen? Seems he’s tried variously 70, 101 and 911. Not clear whether the issue is the router PPPoE with VLAN capability or simply the wrong settings.

I do, my official portal notified Zen VLAN is 70 but in an email they have told me it needs to be 0. I have tried them all.

In reply to a post by Ax88u_Ax86u:

I do, my official portal notified Zen VLAN is 70 but in an email they have told me it needs to be 0. I have tried them all.

Have you got a clean connection using VLAN 70 from a direct connected laptop/PC?

I haven't done that yet. I've got some free time tomorrow afternoon so I'll try it then.

When I change the vlan settings for the ethernet adapter windows crashes. So doesn't look like I'm going to be able to try that. I can set up a basic pppoe connection without crashing but it won't connect.

Can you try Ubuntu on a bootable stick?

Just tried using 'hirsute hippo'. vlan support appears to not be included by default and requires lots of cli jiggery pokery to install. I've run out of time this afternoon as the mob is back soon and will be baying for the internet!

somebody has found a "solution", i say solution in quotes as it may not work

https://www.snbforums.com/threads/rt-ax88u-vlan-tagg...

I don't normaly like to post links to other forums but as this could help you i feel thats fine

Edited by Taras (Wed 22-Sep-21 19:03:10)

Thanks for that, that's one I hadn't come across. I'll check it out.

Did you make any headway with this?

Why not just factory reset the router and set it up again following 0hn83#s guidance.

It could just be down to a bug that's developed as a result of some corrupt data somewhere.

I am on a BT Wholesale FTTP circuit with Zen and am using a Fritzbox 7530 so the help I can give is limited but have had issues with routers before (such as random sites being blocked) that have been fixed by a reset.

Edited by techguy (Fri 24-Sep-21 18:34:27)

Unfortunately not. I'm using my 88u as a wifi access point at the moment and I've bought a draytek v2927ax in the hopes that that will be able to connect. It should arrive towards the end of next week.

Hey buddy

Did you manage to get a third party router working on Cityfibre/Zen FTTP? If so, what settings did you use? VLAN =911?

My area has just been enabled with Cityfibre FTTP and thinking of signing up to Zen's 900/900 service for £40/m but using my own router is a must. My existing router (Netgear RAX200) supports VLAN tagging.

Cheers

I did get a draytek 2927ax to connect easily. Ignore the zen portal settings about vlan and set vlan id to 0. I returned the draytek as it was incredibly slow and am still looking for a viable alternative to the fritzbox.

In reply to a post by Ax88u_Ax86u:

I did get a draytek 2927ax to connect easily. Ignore the zen portal settings about vlan and set vlan id to 0. I returned the draytek as it was incredibly slow and am still looking for a viable alternative to the fritzbox.

Thanks. Did Zen provide you with PPPoE credentials or did you have to extract these yourself from their supplied router? Are you consisntently getting 900 down/900 up speeds?

In reply to a post by Ax88u_Ax86u:

I did get a draytek 2927ax to connect easily. Ignore the zen portal settings about vlan and set vlan id to 0. I returned the draytek as it was incredibly slow and am still looking for a viable alternative to the fritzbox.

Out of interest, what's the issue with the Fritzbox? They seem to be reasonably well regarded for a consumer-grade router.

In reply to a post by candlerb:

In reply to a post by Ax88u_Ax86u:

I did get a draytek 2927ax to connect easily. Ignore the zen portal settings about vlan and set vlan id to 0. I returned the draytek as it was incredibly slow and am still looking for a viable alternative to the fritzbox.

Out of interest, what's the issue with the Fritzbox? They seem to be reasonably well regarded for a consumer-grade router.

AFAIK its only a wifi 5 router so will max out at ~600 Mbps over wifi on the 900 service. A wifi 6 router is an absolute must for getting close to gigabit speeds wirelessly, provided you have wifi 6 clients as well of course. Though in the past I've managed to squeeze ~ 800 Mbps out of a wifi 5 4x4 router (Netgear R7800) paired with a 4x4 wifi client, Asus PCE-AC88U.

Edited by Pizza_Lover (Sun 17-Oct-21 09:52:06)

If that's all, then you could just connect an access point of your choice to the ISP-supplied router. Sort of the "hifi separates" approach.

I don't know if Zen are providing it to new customers yet but the latest iteration of the standard supplied
Fritzbox 7530 is the 7530AX which is wifi 6

A bit of both and the speeds are great yes. Usually about 900/750.

It is the wifi - it's rubbish. Zen will provide the better model for a small monthly fee of course.
I am using my old asus as an access point at the moment.

In reply to a post by Ax88u_Ax86u:

A bit of both and the speeds are great yes. Usually about 900/750.

Did Zen refuse to provide you with full PPPoE details when you asked them? I really don't want to be faffing around 'sniffing' packets from their supplied router in order to capture PPPoE details when a quick phone call should sort it out.

Edited by Pizza_Lover (Sun 17-Oct-21 17:52:44)

username and password with a vlan id of 0 is all I needed and that info is on the portal.

Thought you said earlier in the thread the official Zen portal said it was VLAN 70?

You were rather confused at the time. Has their portal been updated?

No their information is wrong. It definitely needs to be set to 0 and their portal states it needs to be 70. It still says 70 this evening.

I've tried everything now. 101, 911 leaving it blank and still nothing! It's driving me crazy

Please help.

WAN Connection Type: PPPoE
Enable WAN: Yes
Enable NAT: Yes
Enable UPnP: Yes
In the WAN IP Setting section set Get the WAN IP automatically to Yes.
In the WAN DNS Setting section set Connect to DNS Server automatically to Yes.
zenXXXXX@zen
password - per customer portal

IPTV - manual setup - then internet I've tried everything now. 101, 911 leaving it blank and still nothing!

Edited by h1x (Sat 12-Mar-22 08:47:25)

I got stuck for a while trying different methods. Engineer put ONT cable to a LAN port on the fritzbox, instead of the DSL port, with a VLAN ID of 101. Was puzzled by this so I connected the ONT cable to LAN port 4 on the Asus and tried various VLAN IDs - no dice.

What did work was putting it on the DSL port, and its set up as:

Internet VID 911 PRIO 0

All good, the AX86U can max out my 500mbit connection no problem, it's also giving me 900mbit upload, nice to have that uncapped I suppose!