Can't access HA from outside local LAN- DSL Router and PPPoE

Configuration
1

This is my first post ever.
I set up my Home Assistant Raspberry Pi4 at a vacation home using the information in this video : Home Assistant Remote Access for FREE - DuckDNS + LetsEncrypt + Single URL - YouTube
My setup is a DSL router that has been bridged feeding WAN to a TP-Link router configured using PPPoE.
Logging in to my DSL Modem, I see a WAN IP Address of 100.070.xxx.xxx.
Logging in to DuckDNS and/or my laptop, I see a wan IP address of 104.192.xxx.xxx.
My HA RPi4 has a static address of 192.168.1.45. Port forwarding has been done for 8123 to this IP.
The problem: I can log in to HA using my DuckDNS address (mydomain.duckdns.org:8123) when I am on same network as my HA RPi4 (in the same house). When I am away at my other home, I cannot log in to HA.
It has to be a DSL modem because there are no other “broadband” options here.
I do not know enough about network engineering to figure this one out. I looked online and saw something about CGNAT. I hope that someone out there can advise.

2

You need to open port on router to allow connection from outside

From the vacation home you can Google search “what’s my ip” and you will get your public ip. After you verify you can go to http://yourpublicip:8123 and see HA then you can worry about duckdns. Doesn’t have to be 8123 but whatever port you forwarded to HA

3

Thank you for your reply. I realized that I made a mistake in my post.

When I am at my vacation home with the HA RPi4…

  • I log into my router, I get a connection type of PPPoE and an IP of 100.70.xxx.xxx.
  • When I access DuckDNS or use whatismyip on my laptop I get an IP of 104.192.xxx.xxx.
  • I can get into my HA using mydomain.duckdns.org:8123

When I am away from my vacation home…

  • When I am away from the local network that has my Home Assistant RPi4, port forwarding will not work because DuckDNS thinks that my RPi4 is behind 104.192.xxx.xxx, and my router thinks that it is 100.070.xxx.xxx.

I tried your suggestion. I got my IP using whatismyip and it was 104.192.xxx.xxx. Trying to access my HA from 104.192.xxx.xxx:8123 did not work.

Is this something to do with using PPPoE?

4

duckdns will always resolve to same address regardless of location. so if it works locally, it should also work remote.

I strongly do not believe so.

dsl router should just pass through traffic. TP link should get WAN IP. you should only need open port on TP link and point it to HA server. DSL router may be blocking ports. If bridge is setup wrong or in case of some providers some ports are not allowed.

5

Thank you again for your quick reply. Your responses are bringing up a lot of new ideas and I have a lot of learning to do.
What seems to be the problem is that the router and the devices on that routers LAN have different IP addresses. DuckDNS and whatismyip report one IP address, and locally I can get to the HA. When I am away from the local network, it seems that the different IP address of the router is preventing the DuckDNS reported IP address from getting to HA. canyouseeme.org and yougetsignal.com cannot see port 8123 on either of the IP addresses from the router or the local LAN.
I will have to call my ISP tech support. I know nothing of modems and the DSL router might indeed be blocking ports. Most likely the problem is with the modem configuration.
Again, thank you and I will report back to this thread when I have an answer.

6

Did you manage to resolve this at all?

I think I’m in a similar situation. Switched to a new ISP and they use PPPOE and a VLAN tag. IP checking websites think my public IP is different to what my router thinks it is. If I use the IP from websites in DuckDNS I cannot access home assistant, but if I manually override to the IP in my router I can.

My work around will only last as long as my ISP leaves me on that IP. When it changes, I’ll need to redo this effort, as the DuckDNS addon pulls the same, incorrect, IP that websites do.