@VictorSF 

  @VictorSF 

Hi,

What is your WAN (Internet) connection type? Is it PPPoE?

If it is, then verify that the IP address that dnschecker_org resolves for your DNS is indeed the same IP address that your Archer C5400 shows on its Status page for the PPPoE connection.

  @woozle 

Hi,

The router is set to dynamic ip and the ip address is the same on the router and in dnchecker.

When I try to set it to PPPoE it keeps saying connecting and the ip becomes 0.0.0.0

  @VictorSF 

Ok.

What type of broadband Internet connection do you actually have?

I ask, because it is quite rare to have a broadband connection where an Ethernet cable and "Dynamic IP" connects right to the Internet with a public IPv4 address.

In most cases where the router is connected via Dynamic IP there is another device (e.g. modem, ONT) at the other end of the Ethernet cable and that device acquires the public IPv4 address.

  @woozle 

My router is connected directly to the wall.

I have also tried to ask my ISP if they can see any errors but they say that everything looks right on their end. So it's my router that isn't set up correctly, but they couldn't help further :)

I have a Fiber connection provided by my local cable TV provider, if that's what you were asking...
I wasn't sure

  @VictorSF 

If the Internet is routed to your house via TV cable, then I think there should be a cable modem somewhere. Does one of the walls in your home maybe have a smaller metal cover or metal door that can be opened, behind which the TV cable company might house some equipment?

Anyway, can you maybe do the following test?

- Disable the "DMZ" feature on the C5400 for now.
- Go to "Advanced" -> "Administration" -> "Remote Management" and enable remote management for all devices. Set the port to a number you don't already forward to another device. (e.g. 1080)
- Grab another device that is connected to the Internet via a separate Internet connection, like a smartphone with 4G cellular connection, open a web browser and type your DNS name and add port 1080. (e.g. http://mydomainname:1080)

See if that opens the C5400's login screen. If even that doesn't work, then there either must be a problem with your ISPs connection or the IPv4 address of your C5400's WAN is not a true public IPv4 address.

  @woozle 

Thanks,
When you wrote that my router might not have a rigitg public ip, it occurred to me that my ISP might not have opened my router's ip.

I gave them a call today. They say that my incoming traffic was blocked by their firewall. So the technician I spoke to last time either hadn't seen it or forgot to say it.

But all in all, now it works :D thank you very much for the help, nice to have an extra pair of eyes on the matter as I had been staring at it blindly for the last week :P