DuckDNS,Companion,AdGuard as DNS Network Security advice

Configuration
1

My ambition is to setup an AWS hosted Alexa skill in order to use assist on my Amazon echo devices. I have pretty much got this working, the lambda, the skill account linking. However to get it working I have made a number of settings as follows: Stop NGINX addon, change http configuration yaml, dns rewrite on AdGuard addon to write from external duckdns to internal ip address, port forward on router from 443 to 8123 for Alexa skill and adding loop back to network interfaces for ipv4 in home assistant to make sure AdGuard is primary dns not router for home assistant. As far as I can tell all of these changes are ‘working’. I can access my home assistant instance from the web both locally and remotely using duckdns url.

But here’s the question, I cannot get the companion app to accept the same duckdns address for local access as works on mobile web?? I have no idea why. I get 403 forbidden, this does not happen on browser. I’ve tried reinstalling the app.

IMG_2347
IMG_23471284×594 143 KB

IMG_2346
IMG_23461284×2778 289 KB

IMG_2345
IMG_23451284×2778 162 KB

IMG_2344
IMG_23441284×2778 309 KB

IMG_2348
IMG_23481284×2778 243 KB

2

My advice…
Never use AdGuard, PiHole, or any other man-in-the-middle-attack DNS Re-directors if you don’t know exactly what it’s doing and monitor it VERY closely.
It is probably the #1 cause of DNS problems in this forum.

1 Like
3

Thanks for your reply.
The DNS rewrite on AdGuard was really quite a late addition it was in an effort to be able to use the the external duckdns address as the internal url in the iOS companion app. It didn’t help.