Scribbles for my bad memory

I recently signed a new broadband contract with One NZ and received a HUAWEI DN8245X6-10 wifi router. This new router offers WIFI6 connection, which is faster than the Vodafone UltraHub. Unfortunately, I was unable to get port forwarding to work on this router, which was quite frustrating. Even One NZ's customer support couldn't assist me, as they admitted to not having training on port forwarding support. However, they did provide me with some useful information - One NZ doesn't block any ports, and the old Vodafone Ultrahub can also support the cable modem. This gave me some hope. I decided to use the Vodafone Ultrahub as the main router and DN8245 as a secondary WIFI router. After spending a few hours on it this afternoon, I finally made it work. Here are the key steps.

1. Connect the Ultrahub's WAN port to the cable modem. I didn't change any settings; it simply works. I was happy to find that the port map settings work with this new HFC broadband as well!

2. Connect the DN8245X6-10's WAN port to one of the LAN ports of the Ultrahub.

3. Go to http://192.168.1.1/ and log in to the router using "admin" as the username and the password printed on the router.

4. Go to Advanced => Wan.

   • Remove all three existing WAN interfaces.
   • Create a new one with the following settings.
   • Apply.

5. Go to Route => IPV4 default route. (I spent at two hours before I found this step is critical)

   • Enable default route.
   • Set the new WAN interface you just created as the default route.
   • Apply

And, that's all! BTW, don't waste your time to try to set a bridge wan. It simply doesn't work：cannot get an IP from master router for unknown reason.

tl;dr

The root cause is that the default route was not set to the router's IP address.

My journey to resolve the issue:

The issue is that port mapping can work with my raspberry pi while it couldn't work with a virtual machine in the same LAN. I firstly think it must be a bug from the router. I upgrade the router to its latest firmware, but it still doesn't work. I google back and forth, I learned much from all kinds of answers, but they were just not my case. I almost decided to give up.

Then I found the following answer from E. van Putten, he answered this question and nobody gave his answer a "Like"!!!

In case you landed on this page because you can't reach a server running inside a Xen Guest from the internet (but can connect locally), then read on...

1. The fritzbox can get confused by different OS'es appearing from the same MAC-address etc. (could happen while you are setting up / experimenting with Xen)
2. The fritzbox has seemingly duplicate entries in the list, but with different settings, you need to delete the portmap from the incorrect entry, cleanup the list and reapply the portmap settings.
3. It might be that your guest OS has no default gateway IP-address set. You'd expect a default gateway set to the local IP-address of your fritzbox.

The symptoms of a missing default gateway is that your LAN PCs can access the server running inside the guest just fine, but external users from the internet cannot connect.

He gave three possible causes, and my case is the third one! here's my solution

opts = {
    :name => "yt-gateway",
    :ip => "192.168.178.173",
    :mem => "1024",
    :cpu => "1"
}
Vagrant.configure("2") do |config|
  config.vm.box = "bento/ubuntu-20.04"
  config.vm.hostname = opts[:name]
  config.vm.network :public_network, ip: opts[:ip], bridge: "eno1"
  config.vm.provision "shell", run: "always", inline: "route add default gw 192.168.178.1 || true"
  config.vm.provider "virtualbox" do |v|
    v.name = opts[:name]
    v.customize ["modifyvm", :id, "--memory", opts[:mem]]
    v.customize ["modifyvm", :id, "--cpus", opts[:cpu]]
    v.customize ["modifyvm", :id, "--name", opts[:name]]
  end
end

I love you E. van!