Replacing Connect Box 3 with my own router on DSL connection

o_dark_o · 2025-05-23T17:50:23+00:00

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o_dark_o

Hi everyone,

I know this question was asked many times on this forum, and I read success and fail stories, but key data is still missing.

Recently I moved to a location where only DSL internet is available. In my previous apartment I had cable internet with UPC / Sunrise Connect box in bridge mode to which I connected my ASUS ZenWiFi AC router and mesh network and world was a happy place. I could set up VPN, DDNS and all other much needed things.

In my new apartment I received the DSL modem with Connect Box 3 DSL. Obviously, this connection is working, but as my router is assigned private IP from Connect Box 3, all my infrastructure is inaccessible from the outside.

I was able to deduct the following facts from different threads here:

DSL version of Connect Box 3 can’t work in bridge mode
Sunrise support on the forum claims that DSL box should work with any router
IP address is automatically assigned from DSL box via DHCP
Public IP address is IPv4 (as seen on my Connect Box 3)

I tried connecting my Asus router (which is in Automatic IP WAN Connection Type) to DSL box, but it doesn’t get IP. Here I found that DSL box does not support IPv4, only IPv6, which is odd because Connect Box 3 gets public IPv4 address.

I even tried setting up my Asus router from scratch as recommended by Sunrise support here on forum (it is in Wireless router mode / AiMesh Router mode).

And finally, yes I already called technical support without any success.

My questions are:

Are there any additional DHCP settings or any other requirements for a router WAN connection towards DSL box
Do I need to enable IPv6 on WAN connection
Does anyone have exact parameters, and not only that it started working by itself
Do DSL box or router need to be power cycled / rebooted in any particular order
Or does anyone have any tricks in their sleeves to make this work

Thanks and best regards.

Xydocq

hello o_dark_o

The hardware you got from Sunrise doesn’t work with a third party router.

But you can use your own hardware on a DSL connection. You just need to replace all the hardware and get a device that is accepted by Swisscom. A list can be found here.

Daniele_Sunrise

o_dark_o Welcome to the community!

I have just corrected the error regarding IPv4 and the Connect Box 3 DSL. IPv4 is possible in any case.

I have now set NO CGN on your modem. As soon as your modem restarts, No CGN should be active. Can you please test it once? You should then be able to connect your router.

Greetings
Daniele

o_dark_o

Daniele_Sunrise I tested it, but sadly it’s still not working. I restarted DSL box and my router multiple times.

My router has default settings for WAN, to obtain IP via DHCP.

Daniele_Sunrise

o_dark_o The change has been made and is active. I will now check the user manual for your router to see if I can find anything there.

Has the router already been used with a provider? If so, could you please reset it once and test it again?

Greetings
Daniele

Daniele_Sunrise

o_dark_o I have found the QIS in the user manual, can you please start an installation with the wizard?

Greetings
Daniele

o_dark_o

Daniele_Sunrise Thanks for your support! This didn’t work either.

For the record, I did not reset my router to factory settings as suggested by manual, but there is possibility to start the wizard manually. I would strongly like to avoid restarting it to factory settings as I have many other custom configurations for my local network.

The router was used with UPC / Sunrise, as I described in my initial post. It was connected to old Connect Box (white) for cable internet. Connect Box was in bridge mode (modem). In this case my router got public IP automatically.

The only way it works now is if router is connected to Connect Box 3, from which it gets local IP address.
Here is the screenshot of current WAN settings page

Daniele_Sunrise

o_dark_o Unfortunately I don’t have any other solutions.

Can’t you backup your settings and then start a new installation and restore the settings as soon as your router is online?

What happens if you clone the MAC address of the Sunrise modem and enter it into your router?

Greetings
Daniele

o_dark_o

Daniele_Sunrise Sorry for the delay in replying.

I have tried several things so far - I cloned the MAC address, restore the router to factory settings and even enabled IPv6 on my router. None of this worked.

I also sniffed the traffic with WireShark between DSL box and Connect Box 3 from the moment when cable is connected, and between DSL box and my router. What I observed is the following:

DSL and Connect Box 3 publish couple of IPv6 multicast packets, after which Connect Box 3 gets connection
My router does not exchange these packets if IPv6 is disabled. When enabled, it does publish these IPv6 packages, but still does not get connection
My router sends DHCP discovery IPv4 packet (0.0.0.0) but there is no reply from DSL box
I don’t see any IPv4 DHCP packets exchange between DSL box and Connect Box 3

My question is: Is DHCP really enabled on DSL box? And which discovery protocol is used in case of your devices?
Just to be clear that we are talking about same setup, this is what I have vs what I want to achieve:

Best regards,

Darko

Daniele_Sunrise

o_dark_o What happens if you connect your own modem/router directly without the receiver and the Connect Box 3 DSL?

Greetings
Daniele

o_dark_o

Hi Daniele_Sunrise

I can’t connect it that way as my router does not have support for DSL connection (RJ-11), only for Ethernet via RJ-45. I assume DSL Box (receiver) is needed as “translator” between DSL line (RJ-11) to Ethernet.

Daniele_Sunrise

o_dark_o In your case, you will need a Brige or a DSL modem with router function. Any certified modem from Swisscom (DSL) will also work for us.

Here is one example of a bridge:
https://www.brack.ch/zyxel-g-fast-bridge-gm4100-1577674

Greetings and I apologize for not providing all the information’s before.
Daniele

o_dark_o

Daniele_Sunrise So just to clarify - the DSL box (modem / bridge) that I was provided by Sunrise to connect to DSL (the one in picture above) works only with Connect Box 3 Ethernet from Sunrise? There is no chance it can work with any other Ethernet router? Because it looks like almost the same model (only branded to Sunrise) as the one by Zyxel in the link you provided…

There is no any kind of options/configuration that can be done by Sunrise to make this DSL box work with other ethernet routers?

And if I buy certified Swisscom DSL modem, is there any specific configuration or is it just plug-and-play?

Best regards,

Darko

Daniele_Sunrise

o_dark_o The DSL receiver from Sunrise is branded and has its own FW. We cannot provide this receiver for your own configurations. Regarding your question - yes, the DSL receiver from Sunrise only works with the CB3 from Sunrise.

If you buy a Swisscom certified modem, you can plug it in without any further configuration.

Greetings
Daniele

o_dark_o

Daniele_Sunrise Thank you for your feedback and your support so far!

o_dark_o

Hi @Daniele_Sunrise and @Xydocq

To follow up - I bought zyxel DSL bridge and it worked out of the box. My router connected directly to zyxel, and immediately assigned with public IP on WAN port.

Thank you both!