Android: Adding lighthouse DNS server breaks lookups of non-Nebula names

[genpfault]

Adding a lighthouse DNS server to the new DNS Resolvers list breaks resolution of non-Nebula names.

Adding Google's 8.8.8.8 or Quad9's 9.9.9.9 to the list doesn't help, lookups of non-lighthouse names remain broken.

I'm using ping <nebula hostname> or ping google.com in a ConnectBot Protocol: local connection to test name resolution.

Running the v0.8.0 APK on Android 14 (LineageOS 21) on a Pixel 8.

[JackDoan]

You seem to have encountered another unfortunate pitfall related to lighthouse DNS :)

Lighthouses will only resolve nebula names, so if you list them as a primary DNS resolver for your system, you'll fail to resolve non-Nebula hosts. There's two ways to deal with this:

1. Configure a real DNS server to use lighthouse DNS to look up records for your nebula network (kind of a pain)

2. List your nebula hosts in "real" DNS with a "real" domain.

In my opinion, the vast majority of users are best served by the second option.

[genpfault]

Lighthouses will only resolve nebula names, so if you list them as a primary DNS resolver for your system, you'll fail to resolve non-Nebula hosts.

Ah, bummer :(

1. Configure a real DNS server to use lighthouse DNS to look up records for your nebula network (kind of a pain)

That actually wasn't too hard to set up, running dnsmasq on the lighthouse node appears to do the trick with only a few flags, though I did have to move the lighthouse DNS server off of port 53 so dnsmasq could use it:

sudo dnsmasq \
--no-daemon \
--bind-interfaces \
--interface=nebula1 \
--server=/sn/100.100.100.42#53535

(My Nebula hostnames include a made-up internal TLD, sn (ex. lighthouse0.sn), so the --server flag can route queries for that domain to the lighthouse DNS server and "fall through" to the system /etc/resolv.conf server(s) for everything else.)