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Asus RT-AC88U and community fibre - how do I do it?!

johjames

Casual Member
We have just had CF installed. Prior to this we had VM fibre and we used the Asus RT-AC88U as the router, without issue. When I plugged CF's optic fibre network modem into the Asus router, I was met with the 'Your ISP's DHCP does not function properly' message. I suspect some of the Asus settings may need changing, but I'm not sure which or why. What do I need to do to get the router to work and provide internet access please folks?
 
Not sure, but it looks like CF is doing CGNAT and offer IP address within the same class your Asus uses for NAT. If your Asus gives you IP like 192.168.0.x/24 then plug your computer to CF modem/ONT and check if it also gives you IP from the same 192.168.0.0/24 address space. If so, in yours Asus router try changing LAN network space to 192.168.100.0/24 or 10.0.0.0/24 or 172.16.0.0/24.

/24 means netmask: 255.255.255.0
 
@rain111 maybe able to help, they got an Asus working in the community fibre forum:
 
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@johjames

Best first guess is that you need to enable IP V6 on the WAN side (it isn’t required on the LAN side).

With the CG NAT (lower speed) packages you get a “proper” CG NAT address issued by DHCP (in my case the 100.70.xxx.xxx range)


If enabling IPv6 on the WAN side doesn’t sort it, I would back up the configuration and factory reset the router and start again.
 
One further thought.

It might be worth checking if a manufacturer firmware update is available for the router.

I didn’t leave it like that, but my first use of my Draytek with Community Fibre was just to connect to the LAN port on the supplied router. That has potential for LAN address range clashes (you could fix that on the supplied Linksys if needed) but won’t be fussed about IPv6.

There is no need to clone the Linksys MAC address to make your Asus work (from my experience).
 
Not sure, but it looks like CF is doing CGNAT and offer IP address within the same class your Asus uses for NAT. If your Asus gives you IP like 192.168.0.x/24 then plug your computer to CF modem/ONT and check if it also gives you IP from the same 192.168.0.0/24 address space. If so, in yours Asus router try changing LAN network space to 192.168.100.0/24 or 10.0.0.0/24 or 172.16.0.0/24.

/24 means netmask: 255.255.255.0
Thank you.
 
@rain111 maybe able to help, they got an Asus working in the community fibre forum:
Thank you, I had read the post, but it was a wee bit over my head. Hopefully they'll see this post.
 
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@johjames

Best first guess is that you need to enable IP V6 on the WAN side (it isn’t required on the LAN side).

With the CG NAT (lower speed) packages you get a “proper” CG NAT address issued by DHCP (in my case the 100.70.xxx.xxx range)


If enabling IPv6 on the WAN side doesn’t sort it, I would back up the configuration and factory reset the router and start again.
Thank you Barnet, I'll see if I can work out how to do this.
 
One further thought.

It might be worth checking if a manufacturer firmware update is available for the router.

I didn’t leave it like that, but my first use of my Draytek with Community Fibre was just to connect to the LAN port on the supplied router. That has potential for LAN address range clashes (you could fix that on the supplied Linksys if needed) but won’t be fussed about IPv6.

There is no need to clone the Linksys MAC address to make your Asus work (from my experience).
I've updated the firmware on the ASUS router and I haven't even used the Linksys router. As I write, I'm using a Firewalla Purple as the router and the ASUS router as the AP, but I want to change the set-up to use the ASUS as the primary router.
 
@johjames

I'm not familiar with either the "Firewalla Purple" or the "Asus RT-AC88U" but I note from the Firewalla documentation that it supports IPv6 on both the WAN and LAN side.


If the setup works with the Firewalla Purple but not without, I strongly suspect it is IPv6 related (my understanding is that Community Fibre need the device connected to their ONT to support IPv6).

I've had a quick look at the Asus RT-AC88U manual:

https://dlcdnets.asus.com/pub/ASUS/wireless/RT-AC88U/E10302_RT_AC88U_Manual.pdf?model=RT-AC88U

Section 4.4 (page 82) talks about IPv6 and has 4 steps listed.

"Connection type" selection seems the most relevant but sadly doesn't list the choices.

My Draytek (in the similar setup section) has:

Connection Type: DHCPv6 Client

WAN Connection Detection: Always On
Then I have two options unchecked (RIPng Protocol & Bridge Mode).

The Asus manual shows this in the IPv6 setup:

1678608523890.png


What options do you have in "Connection Type"?

Asus' generic support suggests that "Native" might be an option, I would give that a go. If it then offers DHCP try that (edit).

I might start with Router Advertisement off and see how that goes (from my extremely limited understanding that is intended to help IPv6 work on the WAN side which isn't the current objective).

Hope this helps!
 
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@johjames

I'm not familiar with either the "Firewalla Purple" or the "Asus RT-AC88U" but I note from the Firewalla documentation that it supports IPv6 on both the WAN and LAN side.


If the setup works with the Firewalla Purple but not without, I strongly suspect it is IPv6 related (my understanding is that Community Fibre need the device connected to their ONT to support IPv6).

I've had a quick look at the Asus RT-AC88U manual:

https://dlcdnets.asus.com/pub/ASUS/wireless/RT-AC88U/E10302_RT_AC88U_Manual.pdf?model=RT-AC88U

Section 4.4 (page 82) talks about IPv6 and has 4 steps listed.

"Connection type" selection seems the most relevant but sadly doesn't list the choices.

My Draytek (in the similar setup section) has:

Connection Type: DHCPv6 Client

WAN Connection Detection: Always On
Then I have two options unchecked (RIPng Protocol & Bridge Mode).

The Asus manual shows this in the IPv6 setup:

View attachment 5569

What options do you have in "Connection Type"?

Asus' generic support suggests that "Native" might be an option, I would give that a go. If it then offers DHCP try that (edit).

I might start with Router Advertisement off and see how that goes (from my extremely limited understanding that is intended to help IPv6 work on the WAN side which isn't the current objective).

Hope this helps!
Thank you for your generous advice Barnet.

Unfortunately neither IPv6 Native mode, nor Passthrough worked when I used the Asus router in Router mode, and removed the Firewall Purple. I was still met with following message:
Your ISP'S DHCP does not function properly.

The options provided for IPv6 connection type are:
Disable
Native
Static IPv6
Passthrough
FLET'S IPv6 service
Tunnel 6t04
Tunnel 6in4
Tunnel 6rd


Because the internet works with the ONT plugged into the Firewalla Purple, being used in router mode, with the Asus being in AP mode, it does suggest a setting issue.
 
@johjames

Sadly I'm more or less out of ideas.

Clearly it is possible to use an Asus router with Community Fibre as @rain111 got the RT-AX89X working using IPv6 set to "Native".

Interestingly that router worked without IPv6 (at least fully) working.

I wonder if the next step is Asus support.

I would try pointing out to Asus that it works with the "Firewalla Purple" in line and that their RT-AX89X also works so have they got some suggested settings for your RT-AC88U.

It doesn't seem to me like there can be a lot wrong with the setup as the "Firewalla Purple" seems to take DHCP from the downstream (Asus) router.

At the risk of asking the obvious, have you tried powering off both units?

Then power up the Community Fibre ONT until it is stable (as I recall you won't get the final green light at that point) then power up the Asus (set to IPv6 "Native").

You should get traffic indications on the ONT and the Asus WAN port as you power the Asus up and they attempt to negotiate.
 
@johjames , @Barnet and All.

Sorry for not replying, I have not checked the forum for some time.

Anyway, regarding the IPv6, honestly, I haven't done many configurations, I sort of figured it out while reading the ASUS manual for my specific router, seeing your screenshot, it is missing a few things compared to mine, also I can't tell which version you are using, I am going to include a screenshot of how mine is set up and looks I really hope it will be helpful.

ASUS-Wireless-Router-RT-AX89X-IPv6.jpg
 
Thanks to all who responded. The solution was as simple as contacting Community Fibre, who reprovisioned the port at their end. I'd also enabled Ipv6 and entered the Community Fibre router MAC address, but it may be that this wasn't required.
 
My guess is that the enabling IPv6 may have helped in it working once Community Fibre did whatever they did.

Some others have found a call to Community Fibre was needed but I'm not clear what they do to make the connection work with the third party device.

I was set up to use the Community Fibre router MAC address when I first connected my Draytek but didn't find it was needed.
 
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The most common case I've come across in my reading is when the ISP has not delegated a prefix to the device and the change on their side is to delegate an appropriately sized IPv6 prefix.
 
Hi guys,

I stumbled on this thread as I have just moved to CF. I also use the Asus RT-AC88U however I am running the Asuswrt Merlin firmware.

CF came in earlier this morning and installed the line (went with the 1gbps package).

The only configuration change I made to my Asus router was to enable IPV6 based on the settings rain111 posted.

All is working and I didnt touch any other settings such as clone MAC address nor did I need to call CF to make changes on their end.

Figured I would just post up my experience in case it helps other readers.

Cheers,
 
Had CF installed today and had the same issue, I have an AX86U. What fixed it for me was to use the MAC Clone feature in the WAN settings. I just entered the ISP router's MAC, hit apply and it immediately connected. Did not need to mess with IPv6, I still have it disabled.

I think if I'd called to have the port reprovisioned that would have worked too, they would have just authorised my router's MAC. I guess they only want one authorised device connected to their service at a time. I actually called them, but then started googling while waiting to be connected, and then hung up as soon as I got it working. For once I was glad to be put on hold.
 
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