It took me a while to figure out why many of my self-hosted services were intermittently failing to connect on my phone after updating to Android 17. I eventually figured out there's a new ACCESS_LOCAL_NETWORK permission which means the "Nearby devices" permission is now required to access devices on the same network subnet. For an avid self-hoster, this can be quite a bit.
I had my DNS configured so my public-facing server resolved to a local IP address when on my LAN. This meant that my web, immich, xmpp, NTP, jellyfin and DoH servers all resolved to a local IP address on wifi. On Android 17, it all broke without warning. No error messages. No asking for extra permissions. Just silent packet dropping.
I've solved it by configuring my public-facing services to resolve to my external (static) IP address, even when inside the network. I couldn't make any internal services resolve to the external address (SMB, CUPS etc) because they are (obviously) not bound to my WAN interface.
I get why the change was made. A lot of apps were snooping around people's networks to gather intel. A potentially massive privacy violation.
Has anyone else had this issue? Is this the cleanest solution?
I had this issue in firefox. And only firefox. Was pulling my hair for hours. Wish I had been warned.
Anyway I just gave firefox the permission and the issue was resolved. Native apps seem unaffected. Which makes me think maybe this is an opt in setting right now?
I think Firefox also gave me the first clue that something was up.
Native apps all have a backwards-compatible setting so it's allowed by default. That will surely get dropped when Google bumps the minimum Android target API so newly published apps need to explicitly configure it.
I actually went through my apps list and disabled nearby devices for all the apps that don't need it. It's a good security measure. I just don't like how it was rolled out.