topic Re: DDNS with Asus Router in Broadband

DDNS with Asus Router

sinanx — Tue, 27 May 2025 16:37:47 GMT

I want to use DDNS for my Home Assistant to be reached from outside, so I bought an Asus RT-AX53U. I have Full Fibre, I removed Sky router and I connected cable from ONT unit directly to Asus Router WAN input. Wifi etc works fine.

When I try to set DDNS from Asus router settings, its says the Router is behind another router and has a private IP, requiring port forwarding from parent router. In this case I assume router sees ONT as parent modem. Is there a way to use DDNS in this setup?

Re: DDNS with Asus Router

TimmyBGood — Tue, 27 May 2025 17:44:52 GMT

@sinanx wrote:

In this case I assume router sees ONT as parent modem.

I think that's incorrect: while an ONT is indeed a modem, it doesn't do Network Address Translation or have IP functionality (i.e. it's specifically not a 'router')

Re: DDNS with Asus Router

sinanx — Tue, 27 May 2025 18:32:40 GMT

Thanks Timmy. BTW with Sky Router, the connection from ONT is goint to a LAN port. I used WAN port of the Asus Router. might this be the problem?

Or is there any other way to set up DDNS with Sky Full Fibre?

Re: DDNS with Asus Router

cookiemonsteruk — Tue, 27 May 2025 18:35:25 GMT

@sinanx

The asus has a seperate blue wan port whilst with the skyhub you sacrifice a lan port by plugging into lan port 4

Re: DDNS with Asus Router

TimmyBGood — Wed, 28 May 2025 07:09:18 GMT

@sinanx wrote:

BTW with Sky Router, the connection from ONT is goint to a LAN port.

By definition eth #4 is acting as a WAN port when connected an ONT: it has to for the broadband to work. They've just saved some money in manufacturing by using a standard four port ethernet module.

Re: DDNS with Asus Router

jamesn123 — Wed, 28 May 2025 09:26:26 GMT

@sinanx

What WAN IP is your Asus router showing? (Obviously dont post the IP on the forum but is it a public or private one)

Re: DDNS with Asus Router

sinanx — Wed, 28 May 2025 09:32:53 GMT

Thank you all for the answers. I guess it was a transient issue. I reconnected the cables again and now it is working.