feat: forward-by-default, auto recursive mode, Linux install fixes (#27)

* feat: auto recursive mode, fix Linux install

Auto mode (new default): probes a root server on startup; uses
recursive resolution if outbound DNS works, falls back to Quad9 DoH
if blocked. Dashboard shows mode indicator (green/yellow).

Linux install fixes:
- Add DNSStubListener=no to resolved drop-in (frees port 53)
- Configure DNS before starting service (correct ordering)
- Skip 127.0.0.53 in upstream detection
- `numa install` now does everything (service + DNS + CA)
- `numa uninstall` mirrors install (stop service + restore DNS)
- Extract is_loopback_or_stub() for consistent filtering

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* feat: enable DNSSEC validation by default

With recursive as the default mode, DNSSEC validation completes the
trustless resolution chain. Strict mode remains off by default.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* feat: forward search domains to VPC resolver on Linux

Parse search/domain lines from resolv.conf and create conditional
forwarding rules to the original nameserver or AWS VPC resolver
(169.254.169.253). Fixes internal hostname resolution on cloud VMs
where recursive mode can't resolve private DNS zones.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* refactor: single-pass resolv.conf parsing, eliminate redundancies

Parse resolv.conf once for both upstream and search domains instead
of 2-3 reads. Extract CLOUD_VPC_RESOLVER constant. Use &'static str
for mode in StatsResponse. Remove dead read_upstream_from_file.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: macOS install health check, harden recursive probe

Verify numa is listening (API port) before redirecting system DNS on
macOS — if the service fails to start (e.g. port 53 in use), unload
the service and abort instead of breaking DNS. Probe up to 3 root
hints before declaring recursive mode unavailable. Validate IPs from
resolvectl to avoid IPv6 fragment extraction. Extract DEFAULT_API_PORT
constant.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: widen make_rule cfg gate to include Linux

make_rule was gated to macOS-only but discover_linux() calls it for
search domain forwarding rules. CI failed on Linux with E0425.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: forward mode as default, recursive opt-in

Forward mode (transparent proxy to system DNS) is now the default.
Recursive and auto modes are explicit opt-in via config. This avoids
bypassing corporate DNS policies, captive portals, VPC private zones,
and parental controls on first install.

- Move #[default] from Auto to Forward on UpstreamMode
- DNSSEC defaults to off (no-op in forward mode)
- 3-way match in main: Forward/Recursive/Auto with clean separation
- Post-install message suggests mode = "recursive" for sovereignty
- Update README, site, and launch drafts messaging

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

README.md

@@ -8,7 +8,7 @@
 
 A portable DNS resolver in a single binary. Block ads on any network, name your local services (`frontend.numa`), and override any hostname with auto-revert — all from your laptop, no cloud account or Raspberry Pi required.
 
-Built from scratch in Rust. Zero DNS libraries. RFC 1035 wire protocol parsed by hand. Recursive resolution from root nameservers with full DNSSEC chain-of-trust validation. One ~8MB binary, everything embedded.
+Built from scratch in Rust. Zero DNS libraries. RFC 1035 wire protocol parsed by hand. Caching, ad blocking, and local service domains out of the box. Optional recursive resolution from root nameservers with full DNSSEC chain-of-trust validation. One ~8MB binary, everything embedded.
 
 ![Numa dashboard](assets/hero-demo.gif)
 
@@ -24,7 +24,7 @@ sudo numa                              # port 53 requires root
 
 Open the dashboard: **http://numa.numa** (or `http://localhost:5380`)
 
-Set as system DNS: `sudo numa install && sudo numa service start`
+Set as system DNS: `sudo numa install`
 
 ## Local Services
 
@@ -43,7 +43,7 @@ Add path-based routing (`app.numa/api → :5001`), share services across machine
 
 385K+ domains blocked via [Hagezi Pro](https://github.com/hagezi/dns-blocklists). Works on any network — coffee shops, hotels, airports. Travels with your laptop.
 
-Two resolution modes: **forward** (relay to Quad9/Cloudflare via encrypted DoH) or **recursive** (resolve from root nameservers — no upstream dependency, no single entity sees your full query pattern). DNSSEC validates the full chain of trust: RRSIG signatures, DNSKEY verification, DS delegation, NSEC/NSEC3 denial proofs. [Read how it works →](https://numa.rs/blog/posts/dnssec-from-scratch.html)
+By default, Numa forwards to your existing system DNS — everything works as before, just with caching and ad blocking on top. For full privacy, set `mode = "recursive"` — Numa resolves directly from root nameservers. No upstream dependency, no single entity sees your full query pattern. DNSSEC validates the full chain of trust: RRSIG signatures, DNSKEY verification, DS delegation, NSEC/NSEC3 denial proofs. [Read how it works →](https://numa.rs/blog/posts/dnssec-from-scratch.html)
 
 ## LAN Discovery
 

docs/marketing/launch-drafts.md

@@ -0,0 +1,618 @@
+# Launch Drafts
+
+## Lessons Learned
+
+**r/selfhosted** (0 upvotes, hostile) — "replaces Pi-hole" framing triggered
+defensive comparisons. Audience protects their stack.
+
+**r/programare** (26 upvotes, 22 comments, 12K views, 90.6% ratio) — worked
+because it led with technical achievement. But: "what does this offer over
+/etc/hosts?" and "mature solutions exist (dnsmasq, nginx)" were the top
+objections. Tool-replacement angle falls flat with generalist audiences.
+
+**r/webdev** — removed by moderators (self-promotion rules).
+
+Key takeaways:
+
+- Lead with what's *unique*, not what it *replaces*
+- Write like explaining to a colleague, not marketing copy
+- Pick ONE hook per community — don't try to be everything
+- Triple-check the GitHub link works before posting
+- Authentic tone > polished bullets
+- Agree with "just use X" — then show what X can't do
+- Don't oversell the pkarr/token vision — one sentence max
+- Benchmark request from r/programare (Mydocalm) — warm follow-up content
+
+---
+
+## Launch Order
+
+~~0. **r/programare** — done (2026-03-21). 12K views, 26 upvotes, 22 comments.~~
+~~1. **r/webdev** — removed by moderators.~~
+
+~~2. **r/degoogle** — done~~
+~~3. **r/node** — done~~
+
+4. **r/coolgithubprojects** — zero friction, just post the repo
+~~5. **r/sideproject** — done (2026-03-29)~~
+6. **r/dns** — technical DNS audience, recursive + DNSSEC angle
+7. **Show HN** — Tuesday-Thursday, 9-10 AM ET
+8. **r/rust** — same day as HN, technical deep-dive
+9. **r/commandline** — 24h after HN
+10. **r/selfhosted** — only if HN hits front page, lead with recursive + LAN discovery
+11. **r/programare follow-up** — benchmark post + recursive/DNSSEC update
+
+---
+
+## Community Drafts
+
+### Show HN
+
+**Title (72 chars):**
+Show HN: I built a DNS resolver from scratch in Rust – no DNS libraries
+
+**Body:**
+
+I wanted to understand how DNS actually works at the wire level, so I built
+a resolver from scratch. No dns libraries — the RFC 1035 protocol (headers,
+labels, compression pointers, record types) is all hand-parsed. It started
+as a learning project and turned into something I use daily as my system DNS.
+
+What it does today:
+
+- **Forward mode by default** — transparent proxy to your existing DNS with
+  caching and ad blocking. Changes nothing about your network.
+- **Full recursive resolver** — set `mode = "recursive"` and it resolves from
+  root nameservers. No upstream dependency. CNAME chasing, TLD priming, SRTT.
+- **DNSSEC validation** — chain-of-trust verification from root KSK.
+  RSA/SHA-256, ECDSA P-256, Ed25519. Sets the AD bit on verified responses.
+- **Ad blocking** — ~385K+ domains via Hagezi Pro, works on any network
+- **DNS-over-HTTPS** — encrypted upstream (Quad9, Cloudflare, or any
+  provider) as an alternative to recursive mode
+- **`.numa` local domains** — register `frontend.numa → localhost:5173` and
+  it creates both the DNS record and an HTTP/HTTPS reverse proxy with
+  auto-generated TLS certs. WebSocket passthrough works (Vite HMR).
+- **LAN service discovery** — run Numa on two machines, they find each other
+  via UDP multicast. Zero config.
+- **Developer overrides** — point any hostname to any IP, auto-reverts
+  after N minutes. REST API for scripting.
+
+Single binary, macOS + Linux. `sudo numa install` and it's your system DNS —
+forward mode by default, recursive when you're ready.
+
+The interesting technical bits: the recursive resolver walks root → TLD →
+authoritative with iterative queries, caching NS/DS/DNSKEY records at each
+hop. DNSSEC validation verifies RRSIG signatures against DNSKEY, walks the
+chain via DS records up to the hardcoded root trust anchor. ECDSA P-256
+verification takes 174ns (benchmarked with criterion). Cold-cache validation
+for a new domain is ~90ms, with only 1 network fetch needed (TLD chain is
+pre-warmed on startup). SRTT-based nameserver selection learns which
+servers respond fastest — average recursive query drops from 2.8s to
+237ms after warmup (12x).
+
+It also handles hostile networks: if your ISP blocks UDP port 53,
+Numa detects this after 3 failures and switches all
+queries to TCP automatically. Resets when you change networks. RFC 7816
+query minimization means root servers only see the TLD, not your full
+query.
+
+The DNS cache adjusts TTLs on read (remaining time, not original). Each
+query is an async tokio task. EDNS0 with DO bit and 1232-byte payload
+(DNS Flag Day 2020).
+
+Longer term I want to add pkarr/DHT resolution for self-sovereign DNS,
+but that's future work.
+
+https://github.com/razvandimescu/numa
+
+---
+
+### r/rust
+
+**Title:** I built a recursive DNS resolver from scratch in Rust — DNSSEC, no DNS libraries
+
+**Body:**
+
+I've been building a DNS resolver in Rust as a learning project that became
+my daily driver. The entire DNS wire protocol is implemented by hand —
+no `trust-dns`, no `hickory-dns`, no `simple-dns`. Headers, label sequences,
+compression pointers, EDNS, all of it.
+
+Some things I found interesting while building this:
+
+**Recursive resolution** — iterative queries from root hints, walking
+root → TLD → authoritative. CNAME chasing, A+AAAA glue extraction from
+additional sections, referral depth limits. TLD priming pre-warms NS + DS +
+DNSKEY for 34 gTLDs + EU ccTLDs on startup.
+
+**DNSSEC chain-of-trust** — the most involved part. Verify RRSIG signatures
+against DNSKEY, walk DS records up to the hardcoded root KSK (key tag 20326).
+Uses `ring` for crypto: RSA/SHA-256, ECDSA P-256 (174ns per verify), Ed25519.
+RFC 3110 RSA keys need converting to PKCS#1 DER for ring — wrote an ASN.1
+encoder for that. RRSIG time validity checks per RFC 4035 §5.3.1.
+
+**NSEC/NSEC3 denial proofs** — proving a name *doesn't* exist is harder than
+proving it does. NSEC uses canonical DNS name ordering to prove gap coverage.
+NSEC3 uses iterated SHA-1 hashing + base32hex + a 3-part closest encloser
+proof (RFC 5155 §8.4). Both require authority-section RRSIG verification.
+
+**Wire protocol parsing** — DNS uses a binary format with label compression
+(pointers back into the packet via 2-byte offsets). Parsing this correctly
+is surprisingly tricky because pointers can chain. I use a `BytePacketBuffer`
+that tracks position and handles jumps.
+
+**Performance** — TLD chain pre-warming means cold-cache DNSSEC validation
+needs ~1 DNSKEY fetch (down from 5). Referral DS piggybacking caches DS
+from authority sections during resolution. ECDSA P-256 verify: 174ns.
+RSA/SHA-256: 10.9µs. DS verify: 257ns.
+
+**LAN service discovery** — Numa instances on the same network find each
+other via UDP multicast. The tricky part was self-filtering: I initially
+filtered by IP, but two instances on the same host share an IP. Switched to
+a per-process instance ID (`pid ^ nanos`).
+
+**Auto TLS** — generates a local CA + per-service certs using `rcgen`.
+`numa install` trusts the CA in the OS keychain. HTTPS proxy via `rustls` +
+`tokio-rustls`.
+
+Single binary, no runtime dependencies. Uses `tokio`, `axum` (REST
+API/dashboard), `hyper` (reverse proxy), `ring` (DNSSEC crypto), `reqwest`
+(DoH), `socket2` (multicast), `rcgen` + `rustls` (TLS).
+
+Happy to discuss any of the implementation decisions.
+
+https://github.com/razvandimescu/numa
+
+---
+
+### r/degoogle
+
+**Title:** I replaced cloud DNS with a recursive resolver — resolves from root, no upstream, DNSSEC
+
+**Body:**
+
+I wanted a DNS setup with zero cloud dependency. No NextDNS account,
+no Cloudflare dashboard, no Pi-hole appliance, no upstream resolver seeing
+my queries. Just a single binary on my laptop that resolves everything
+itself.
+
+Built one in Rust. What it does:
+
+- **Forward mode by default** — transparent proxy to your existing DNS with
+  caching and ad blocking. Changes nothing about your network.
+- **Recursive resolution** — set `mode = "recursive"` and it resolves directly
+  from root nameservers. No Quad9, no Cloudflare, no upstream dependency.
+  Each authoritative server only sees the query for its zone — no single
+  entity sees your full browsing pattern.
+- **DNSSEC validation** — verifies the chain of trust from root KSK.
+  Responses are cryptographically verified — no one can tamper with them
+  in transit.
+- **System-level ad blocking** — Hagezi Pro list (~385K+ domains),
+  works on any network. Coffee shop WiFi, airport, hotel.
+- **ISP resistant** — in recursive mode, if UDP is blocked Numa switches
+  to TCP automatically. Or set `mode = "auto"` to probe on startup and
+  fall back to encrypted DoH if needed.
+- **Query minimization** — root servers only see the TLD (.com), not
+  your full domain. RFC 7816.
+- **Zero telemetry, zero cloud** — all data stays on your machine. No
+  account, no login, no analytics. Config is a single TOML file.
+- **Local service naming** — bonus for developers: `https://app.numa`
+  instead of `localhost:3000`, with auto-generated TLS certs
+
+Single binary, macOS + Linux. `sudo numa install` and it's your system
+DNS — forward mode by default, recursive when you're ready. No Docker,
+no PHP, no external dependencies.
+
+The DNS wire protocol is parsed from scratch — no DNS libraries. You can
+read every line of code.
+
+```
+brew install razvandimescu/tap/numa
+# or
+cargo install numa
+```
+
+MIT license. https://github.com/razvandimescu/numa
+
+---
+
+### r/node
+
+**Title:** I replaced localhost:5173 with frontend.numa — auto HTTPS, HMR works, no nginx
+
+**Body:**
+
+Running a Vite frontend on :5173, Express API on :3000, maybe docs on
+:4000 — I could never remember which port was which. And CORS between
+`localhost:5173` and `localhost:3000` is its own special hell.
+
+How do you get named domains with HTTPS locally?
+
+1. /etc/hosts + mkcert + nginx
+2. dnsmasq + mkcert + Caddy
+3. `sudo numa`
+
+What it actually does:
+
+```
+curl -X POST localhost:5380/services \
+  -d '{"name":"frontend","target_port":5173}'
+```
+
+Now `https://frontend.numa` works in my browser. Green lock, valid cert.
+
+- **HMR works** — Vite, webpack, socket.io all pass through the proxy.
+  No special config.
+- **CORS solved** — `frontend.numa` and `api.numa` share the `.numa`
+  cookie domain. Cross-service auth just works.
+- **Path routing** — `app.numa/api → :3000`, `app.numa/auth → :3001`.
+  Like nginx location blocks, zero config files.
+
+No mkcert, no nginx.conf, no Caddyfile, no editing /etc/hosts.
+Single binary, one command.
+
+```
+brew install razvandimescu/tap/numa
+# or
+cargo install numa
+```
+
+https://github.com/razvandimescu/numa
+
+---
+
+### r/dns
+
+**Title:** Numa — recursive DNS resolver from scratch in Rust, DNSSEC, no DNS libraries
+
+**Body:**
+
+I built a recursive DNS resolver where the entire wire protocol (RFC 1035 —
+headers, label compression, EDNS0) is hand-parsed. No `hickory-dns`,
+no `trust-dns`.
+
+What it does:
+- Full recursive resolver from root hints (iterative queries, no upstream needed)
+- DNSSEC chain-of-trust validation (RSA/SHA-256, ECDSA P-256, Ed25519)
+- EDNS0 with DO bit, 1232-byte payload (DNS Flag Day 2020 compliant)
+- DNS-over-HTTPS as an alternative upstream mode
+- Ad blocking (~385K+ domains via Hagezi Pro)
+- Conditional forwarding (auto-detects Tailscale/VPN split-DNS)
+- Local zones, ephemeral overrides with auto-revert via REST API
+
+DNSSEC implementation: DNSKEY/DS/RRSIG record parsing, canonical wire format
+for signed data, key tag computation (RFC 4034), DS digest verification.
+Chain walks from zone → TLD → root trust anchor. ECDSA P-256 signature
+verification in 174ns. TLD chain pre-warmed on startup. Referral DS records
+piggybacked from authority sections during resolution.
+
+NSEC/NSEC3 authenticated denial of existence: NXDOMAIN gap proofs, NSEC3
+closest encloser proofs (3-part per RFC 5155), NODATA type absence proofs,
+authority-section RRSIG verification. Iteration cap at 500 for NSEC3 DoS
+prevention.
+
+What it doesn't do (yet): no authoritative zone serving (AXFR/NOTIFY).
+
+Single binary, macOS + Linux. MIT license.
+
+https://github.com/razvandimescu/numa
+
+---
+
+### Lobsters (invite-only)
+
+**Title:** Numa — DNS resolver from scratch in Rust, no DNS libraries
+
+**Body:**
+
+I built a DNS resolver in Rust — RFC 1035 wire protocol parsed by hand,
+no `trust-dns` or `hickory-dns`. Started as a learning project, became
+my daily system DNS.
+
+Beyond resolving, it does local `.numa` domains with auto HTTPS reverse
+proxy (register `frontend.numa → localhost:5173`, get a green lock and
+WebSocket passthrough), and LAN service discovery via UDP multicast —
+two machines running Numa find each other's services automatically.
+
+Implementation bits I found interesting: DNS label compression (chained
+2-byte pointers back into the packet), browsers rejecting wildcard certs
+under single-label TLDs (`*.numa` fails — need per-service SANs), and
+`SO_REUSEPORT` on macOS for multiple processes binding the same multicast
+port.
+
+Set `mode = "recursive"` for DNSSEC-validated resolution from root
+nameservers — no upstream, no middleman.
+
+Single binary, macOS + Linux.
+
+https://github.com/razvandimescu/numa
+
+---
+
+### r/coolgithubprojects
+
+**Post type:** Image post with `hero-demo.gif`, GitHub link in first comment.
+
+**Title:** Numa — portable DNS resolver built from scratch in Rust. Ad blocking, local HTTPS domains, LAN discovery, recursive resolution with DNSSEC. Single binary.
+
+**First comment (post immediately):**
+
+https://github.com/razvandimescu/numa
+
+```
+brew install razvandimescu/tap/numa && sudo numa
+```
+
+No DNS libraries — RFC 1035 wire protocol parsed by hand.
+Recursive resolution from root nameservers with full DNSSEC
+chain-of-trust validation. 385K+ blocked ad domains.
+.numa local domains with auto TLS and WebSocket proxy.
+
+---
+
+### r/sideproject
+
+**Title:** I built a DNS resolver from scratch in Rust — it's now my daily system DNS
+
+**Body:**
+
+Last year I wanted to understand how DNS actually works at the wire
+level, so I started parsing RFC 1035 packets by hand. No DNS libraries,
+no trust-dns, no hickory-dns — just bytes and the spec.
+
+It turned into something I use every day. What it does now:
+
+- **Ad blocking** on any network (coffee shops, airports) — 385K+
+  domains blocked, travels with my laptop
+- **Local service naming** — `https://frontend.numa` instead of
+  `localhost:5173`, with auto-generated TLS certs and WebSocket
+  passthrough for HMR
+- **Recursive resolution** from root nameservers with DNSSEC
+  chain-of-trust validation — set `mode = "recursive"` for full
+  privacy, no upstream dependency, no single entity sees my query
+  pattern
+- **LAN discovery** — two machines running Numa find each other's
+  services automatically via mDNS
+
+Single Rust binary, ~8MB, MIT license. `sudo numa install` and it's your
+system DNS — caching, ad blocking, .numa domains, zero config changes.
+
+I wrote about the technical journey here:
+- [I Built a DNS Resolver from Scratch](https://numa.rs/blog/posts/dns-from-scratch.html)
+- [Implementing DNSSEC from Scratch](https://numa.rs/blog/posts/dnssec-from-scratch.html)
+
+https://github.com/razvandimescu/numa
+
+---
+
+### r/webdev (Showoff Saturday — posted 2026-03-28)
+
+**Title:** I replaced localhost:5173 with frontend.numa — shared cookie domain, auto HTTPS, no nginx
+
+**Body:**
+
+The port numbers weren't the real problem. It was CORS between
+`localhost:5173` and `localhost:3000`, Secure cookies not setting over
+HTTP, and service workers requiring a secure context.
+
+I built a DNS resolver that gives local services named domains under a
+shared TLD:
+
+```
+curl -X POST localhost:5380/services \
+  -d '{"name":"frontend","target_port":5173}'
+```
+
+Now `https://frontend.numa` and `https://api.numa` share the `.numa`
+cookie domain. Cross-service auth just works. Secure cookies set.
+Service workers run.
+
+What's under the hood:
+- **Auto HTTPS** — generates a local CA + per-service TLS certs. Green
+  lock, no mkcert.
+- **WebSocket passthrough** — Vite/webpack HMR goes through the proxy.
+  No special config.
+- **Path routing** — `app.numa/api → :3000`, `app.numa/auth → :3001`.
+  Like nginx location blocks.
+- **Also a full DNS resolver** — forward mode with caching and ad
+  blocking by default. Set `mode = "recursive"` for full DNSSEC-validated
+  resolution from root nameservers.
+
+Single Rust binary. `sudo numa install` and it's your system DNS — caching,
+ad blocking, .numa domains. No nginx, no Caddy, no /etc/hosts.
+
+```
+brew install razvandimescu/tap/numa
+# or
+cargo install numa
+```
+
+https://github.com/razvandimescu/numa
+
+**Lessons from r/node (2026-03-24):** "Can't remember 3 ports?" got
+pushback — the CORS/cookie angle resonated more. Lead with what you
+can't do without it, not what's annoying.
+
+---
+
+### r/commandline
+
+**Title:** numa — local dev DNS with auto HTTPS and LAN service discovery, single Rust binary
+
+**Body:**
+
+I run 5-6 local services and wanted named domains with HTTPS instead of
+remembering port numbers. Built a DNS resolver that handles `.numa`
+domains:
+
+```
+curl -X POST localhost:5380/services \
+  -d '{"name":"api","target_port":8000}'
+```
+
+Now `https://api.numa` resolves, proxies to localhost:8000, and has a
+valid TLS cert. WebSocket passthrough works — Vite HMR goes through
+the proxy fine.
+
+The part I didn't expect to be useful: LAN service discovery. Two
+machines running numa find each other via UDP multicast. I register
+`api.numa` on my laptop, my teammate's numa instance picks it up
+automatically. Zero config.
+
+Also blocks ~385K+ ad domains since it's already your DNS resolver.
+Portable — works on any network (coffee shops, airports). Set
+`mode = "recursive"` for full DNSSEC-validated resolution from root
+nameservers — no upstream dependency.
+
+```
+brew install razvandimescu/tap/numa
+sudo numa
+```
+
+Single binary, DNS wire protocol parsed from scratch (no DNS libraries).
+
+https://github.com/razvandimescu/numa
+
+---
+
+### r/selfhosted (only if Show HN hits front page)
+
+**Title:** Numa — recursive resolver + ad blocking + LAN service discovery in one binary
+
+**Body:**
+
+I built a DNS resolver in Rust that I've been running as my system DNS.
+Two features I'm most proud of:
+
+**Recursive resolution + DNSSEC** — set `mode = "recursive"` and it resolves
+from root nameservers, no upstream dependency. Chain-of-trust verification
+(RSA, ECDSA, Ed25519), NSEC/NSEC3 denial proofs. No single entity sees your
+full query pattern — each authoritative server only sees its zone's queries.
+
+**LAN service discovery** — I register `api.numa → localhost:8000` on my
+laptop. My colleague's machine, also running Numa, picks it up via UDP
+multicast — `api.numa` resolves to my IP on his machine. Zero config.
+
+The rest of what it does:
+- **Ad blocking** — ~385K+ domains (Hagezi Pro), portable. Works on any
+  network including coffee shops and airports.
+- **DNS-over-HTTPS** — encrypted upstream as an alternative to recursive mode.
+- **Auto HTTPS for local services** — generates a local CA + per-service
+  TLS certs. `https://frontend.numa` with a green lock, WebSocket passthrough.
+- **Hub mode** — point other devices' DNS to it, they get ad blocking +
+  `.numa` resolution without installing anything.
+
+Replaces Pi-hole + Unbound in one binary. No Raspberry Pi, no Docker, no PHP.
+
+Single binary, macOS + Linux. Config is one optional TOML file.
+
+**What it doesn't do (yet):** No web-based config editor (TOML + REST API).
+DoT listener is in progress.
+
+`brew install razvandimescu/tap/numa` or `cargo install numa`
+
+https://github.com/razvandimescu/numa
+
+---
+
+## Preparation Checklist
+
+- [ ] Verify GitHub repo is PUBLIC before any post
+- [ ] Build some comment history on posting account first
+- [ ] Post HN Tuesday-Thursday, 9-10 AM Eastern
+- [ ] Respond to every comment within 2 hours for the first 6 hours
+- [ ] Have fixes ready to ship within 24h for reported issues
+- [ ] Don't oversell the pkarr/token vision — one sentence max
+
+## Rules
+
+- Verify GitHub repo is PUBLIC before every post
+- Use an account with comment history, not a fresh one
+- Respond to every comment within 2 hours
+- Never be defensive — acknowledge valid criticism, redirect
+- If someone says "just use X" — agree it works, explain what's *uniquely different*
+- Lead with unique capabilities, not tool replacement
+
+---
+
+## Prepared Responses
+
+**"What does this offer over /etc/hosts?"** *(actual r/programare objection)*
+/etc/hosts is static and per-machine. Numa gives you: auto-revert after N
+minutes (great for testing), a REST API so scripts can create/remove entries,
+HTTPS reverse proxy with auto TLS, and LAN discovery so you don't have to
+edit hosts on every device. Different tools for different problems.
+
+**"Mature solutions already exist (dnsmasq, nginx, etc.)"** *(actual r/programare objection)*
+Absolutely — and they're great. The thing they don't do: register a service
+on machine A and have it automatically appear on machine B via multicast.
+Numa integrates DNS + reverse proxy + TLS + discovery into one binary so
+those pieces work together. If you only need DNS forwarding, dnsmasq is the
+right tool.
+
+**"Why not Pi-hole / AdGuard Home?"**
+They're network appliances — need dedicated hardware or Docker. Numa is a
+single binary on your laptop. When you move to a coffee shop, your ad
+blocking comes with you. Plus the reverse proxy + LAN discovery.
+
+**"Why from scratch / no DNS libraries?"**
+Started as a learning project to understand the wire protocol. Turned out
+having full control over the pipeline makes features like conditional
+forwarding and override injection trivial — they're just steps in the
+resolution chain.
+
+**"Vibe coded / AI generated?"**
+I use AI as a coding partner — same as using Stack Overflow or pair
+programming. I make the architecture decisions, direct what gets built,
+and review everything. The DNS wire protocol parser was the original
+learning project I wrote by hand. Later features were built collaboratively
+with AI assistance. You can read every line — nothing is opaque generated
+slop.
+
+**"Why sudo / why port 53?"**
+Port 53 requires root on Unix. Numa only needs it for the UDP socket.
+You can also bind to a high port for testing: `bind_addr = "127.0.0.1:5353"`.
+
+**"What about .numa TLD conflicts?"**
+The TLD is configurable in `numa.toml`. If `.numa` ever becomes official,
+change it to anything else.
+
+**"Does it support DoH/DoT?"**
+DoH is built in — set `address = "https://9.9.9.9/dns-query"` in
+`[upstream]` and your queries are encrypted. Or set `mode = "auto"` to
+probe root servers and fall back to DoH if blocked. DoT listener support
+is in progress (PR #25).
+
+**"But Quad9/Cloudflare still sees my queries"**
+In forward mode (the default), yes — your upstream resolver sees your queries.
+Set `mode = "recursive"` and Numa resolves directly from root nameservers —
+no single upstream sees your full query pattern. Each authoritative server
+only sees the query relevant to its zone. Add `[dnssec] enabled = true` to
+cryptographically verify responses.
+
+**"Show me benchmarks / performance numbers"** *(actual r/programare request)*
+Benchmark suite is in `benches/` (criterion). Cached round-trip: 691ns.
+Pipeline throughput: ~2.0M qps. DNSSEC: ECDSA P-256 verify 174ns, RSA/SHA-256
+10.9µs, DS verify 257ns. Cold-cache DNSSEC validation ~90ms (1 network fetch,
+TLD chain pre-warmed). Full comparison against system resolver, Quad9,
+Cloudflare, Google on the site.
+
+**"Why not just use Unbound?"**
+Numa supports recursive resolution with DNSSEC validation, same as Unbound
+(`mode = "recursive"`). The difference:
+Numa also has built-in ad blocking, a dashboard, `.numa` local domains with
+auto HTTPS, LAN service discovery, and developer overrides. Unbound does
+one thing well; Numa integrates six features into one binary.
+
+**"Why not Technitium?"**
+Technitium is the closest in features — recursive, DNSSEC, ad blocking,
+dashboard. Good tool. Two differences: (1) Numa is a single static binary,
+Technitium requires the .NET runtime; (2) Numa has developer tooling that
+Technitium doesn't — `.numa` local domains with auto TLS reverse proxy,
+path-based routing, LAN service discovery, ephemeral overrides with
+auto-revert. Different audiences: Technitium targets server admins, Numa
+targets developers on laptops.
+
+**"Does it support Windows?"**
+macOS and Linux are the primary targets. Windows has scaffolding in the code
+but is not tested. If there's demand, it's on the list.

install.sh

@@ -70,8 +70,10 @@ echo ""
 echo "  \033[38;2;107;124;78mInstalled:\033[0m $INSTALL_DIR/numa ($TAG)"
 echo ""
 echo "  Get started:"
-echo "    sudo numa                    # start the DNS server"
+echo "    sudo numa install            # install service + set as system DNS"
-echo "    sudo numa install            # set as system DNS"
-echo "    sudo numa service start      # run as persistent service"
 echo "    open http://localhost:5380   # dashboard"
 echo ""
+echo "  Other commands:"
+echo "    sudo numa                    # run in foreground (no service)"
+echo "    sudo numa uninstall          # restore original DNS"
+echo ""

site/dashboard.html

@@ -882,6 +882,9 @@ async function refresh() {
     document.getElementById('footerUpstream').textContent = stats.upstream || '';
     document.getElementById('footerConfig').textContent = stats.config_path || '';
     document.getElementById('footerData').textContent = stats.data_dir || '';
+    const modeEl = document.getElementById('footerMode');
+    modeEl.textContent = stats.mode || '—';
+    modeEl.style.color = stats.mode === 'recursive' ? 'var(--emerald)' : 'var(--amber)';
     document.getElementById('footerDnssec').textContent = stats.dnssec ? 'on' : 'off';
     document.getElementById('footerDnssec').style.color = stats.dnssec ? 'var(--emerald)' : 'var(--text-dim)';
     document.getElementById('footerSrtt').textContent = stats.srtt ? 'on' : 'off';
@@ -1236,6 +1239,7 @@ setInterval(refresh, 2000);
   Config: <span id="footerConfig" style="user-select:all;color:var(--emerald);"></span>
   · Data: <span id="footerData" style="user-select:all;color:var(--emerald);"></span>
   · Upstream: <span id="footerUpstream" style="user-select:all;color:var(--emerald);"></span>
+  · Mode: <span id="footerMode" style="color:var(--text-dim);">—</span>
   · DNSSEC: <span id="footerDnssec" style="color:var(--text-dim);">—</span>
   · SRTT: <span id="footerSrtt" style="color:var(--text-dim);">—</span>
   · Logs: <span style="user-select:all;color:var(--emerald);">macOS: /usr/local/var/log/numa.log · Linux: journalctl -u numa -f</span>

site/index.html

@@ -4,10 +4,10 @@
 <meta charset="UTF-8">
 <meta name="viewport" content="width=device-width, initial-scale=1.0">
 <title>Numa — DNS you own. Everywhere you go.</title>
-<meta name="description" content="DNS you own. Recursive resolver with full DNSSEC validation, ad blocking, .numa local domains, developer overrides. A single portable binary built from scratch in Rust.">
+<meta name="description" content="DNS you own. Portable DNS resolver with caching, ad blocking, .numa local domains, developer overrides. Optional recursive resolution with full DNSSEC validation. Built from scratch in Rust.">
 <link rel="canonical" href="https://numa.rs">
 <meta property="og:title" content="Numa — DNS you own. Everywhere you go.">
-<meta property="og:description" content="Recursive DNS resolver with full DNSSEC validation, ad blocking, .numa local domains, and developer overrides. Built from scratch in Rust.">
+<meta property="og:description" content="Portable DNS resolver with caching, ad blocking, .numa local domains, and developer overrides. Optional recursive resolution with full DNSSEC validation. Built from scratch in Rust.">
 <meta property="og:type" content="website">
 <meta property="og:url" content="https://numa.rs">
 <link rel="stylesheet" href="/fonts/fonts.css">
@@ -1232,17 +1232,17 @@ footer .closing {
     <div class="reveal">
       <div class="section-label">How It Works</div>
       <h2>What it does today</h2>
-      <p class="lead">A recursive DNS resolver with DNSSEC validation, ad blocking, local service domains, and a REST API. Everything runs in a single binary.</p>
+      <p class="lead">A DNS resolver with caching, ad blocking, local service domains, and a REST API. Optional recursive resolution with DNSSEC. Everything runs in a single binary.</p>
     </div>
     <div class="layers-grid">
       <div class="layer-card reveal reveal-delay-1">
         <div class="layer-badge">Layer 1</div>
         <h3>Resolve &amp; Protect</h3>
         <ul>
-          <li>Recursive resolution &mdash; resolve from root nameservers, no upstream needed</li>
+          <li>Forward mode by default &mdash; transparent proxy to your existing DNS, with caching</li>
-          <li>DNSSEC validation &mdash; chain-of-trust + NSEC/NSEC3 denial proofs (RSA, ECDSA, Ed25519)</li>
           <li>Ad &amp; tracker blocking &mdash; 385K+ domains, zero config</li>
-          <li>DNS-over-HTTPS &mdash; encrypted upstream as alternative to recursive mode</li>
+          <li>Recursive resolution &mdash; opt-in, resolve from root nameservers, no upstream needed</li>
+          <li>DNSSEC validation &mdash; chain-of-trust + NSEC/NSEC3 denial proofs (RSA, ECDSA, Ed25519)</li>
           <li>TTL-aware caching (sub-ms lookups)</li>
           <li>Single binary, portable &mdash; macOS, Linux, and Windows</li>
         </ul>

src/api.rs

@@ -160,6 +160,7 @@ struct QueryLogResponse {
 struct StatsResponse {
     uptime_secs: u64,
     upstream: String,
+    mode: &'static str, // "recursive" or "forward" — never "auto" at runtime
     config_path: String,
     data_dir: String,
     dnssec: bool,
@@ -486,6 +487,7 @@ async fn stats(State(ctx): State<Arc<ServerCtx>>) -> Json<StatsResponse> {
     Json(StatsResponse {
         uptime_secs: snap.uptime_secs,
         upstream,
+        mode: ctx.upstream_mode.as_str(),
         config_path: ctx.config_path.clone(),
         data_dir: ctx.data_dir.to_string_lossy().to_string(),
         dnssec: ctx.dnssec_enabled,

src/config.rs

@@ -59,18 +59,31 @@ fn default_bind_addr() -> String {
     "0.0.0.0:53".to_string()
 }
 
+pub const DEFAULT_API_PORT: u16 = 5380;
+
 fn default_api_port() -> u16 {
-    5380
+    DEFAULT_API_PORT
 }
 
 #[derive(Deserialize, Default, PartialEq, Eq, Clone, Copy)]
 #[serde(rename_all = "lowercase")]
 pub enum UpstreamMode {
+    Auto,
     #[default]
     Forward,
     Recursive,
 }
 
+impl UpstreamMode {
+    pub fn as_str(&self) -> &'static str {
+        match self {
+            UpstreamMode::Auto => "auto",
+            UpstreamMode::Forward => "forward",
+            UpstreamMode::Recursive => "recursive",
+        }
+    }
+}
+
 #[derive(Deserialize)]
 pub struct UpstreamConfig {
     #[serde(default)]
@@ -103,10 +116,14 @@ impl Default for UpstreamConfig {
     }
 }
 
-fn default_srtt() -> bool {
+fn default_true() -> bool {
     true
 }
 
+fn default_srtt() -> bool {
+    default_true()
+}
+
 fn default_prime_tlds() -> Vec<String> {
     vec![
         // gTLDs

src/main.rs

@@ -17,8 +17,7 @@ use numa::query_log::QueryLog;
 use numa::service_store::ServiceStore;
 use numa::stats::ServerStats;
 use numa::system_dns::{
-    discover_system_dns, install_service, install_system_dns, restart_service, service_status,
+    discover_system_dns, install_service, restart_service, service_status, uninstall_service,
-    uninstall_service, uninstall_system_dns,
 };
 
 #[tokio::main]
@@ -31,12 +30,12 @@ async fn main() -> numa::Result<()> {
     let arg1 = std::env::args().nth(1).unwrap_or_default();
     match arg1.as_str() {
         "install" => {
-            eprintln!("\x1b[1;38;2;192;98;58mNuma\x1b[0m — configuring system DNS\n");
+            eprintln!("\x1b[1;38;2;192;98;58mNuma\x1b[0m — installing\n");
-            return install_system_dns().map_err(|e| e.into());
+            return install_service().map_err(|e| e.into());
         }
         "uninstall" => {
-            eprintln!("\x1b[1;38;2;192;98;58mNuma\x1b[0m — restoring system DNS\n");
+            eprintln!("\x1b[1;38;2;192;98;58mNuma\x1b[0m — uninstalling\n");
-            return uninstall_system_dns().map_err(|e| e.into());
+            return uninstall_service().map_err(|e| e.into());
         }
         "service" => {
             let sub = std::env::args().nth(2).unwrap_or_default();
@@ -107,6 +106,46 @@ async fn main() -> numa::Result<()> {
     // Discover system DNS in a single pass (upstream + forwarding rules)
     let system_dns = discover_system_dns();
 
+    let root_hints = numa::recursive::parse_root_hints(&config.upstream.root_hints);
+
+    let (resolved_mode, upstream_auto, upstream, upstream_label) = match config.upstream.mode {
+        numa::config::UpstreamMode::Auto => {
+            info!("auto mode: probing recursive resolution...");
+            if numa::recursive::probe_recursive(&root_hints).await {
+                info!("recursive probe succeeded — self-sovereign mode");
+                let dummy = Upstream::Udp("0.0.0.0:0".parse().unwrap());
+                (
+                    numa::config::UpstreamMode::Recursive,
+                    false,
+                    dummy,
+                    "recursive (root hints)".to_string(),
+                )
+            } else {
+                log::warn!("recursive probe failed — falling back to Quad9 DoH");
+                let client = reqwest::Client::builder()
+                    .use_rustls_tls()
+                    .build()
+                    .unwrap_or_default();
+                let url = "https://dns.quad9.net/dns-query".to_string();
+                let label = url.clone();
+                (
+                    numa::config::UpstreamMode::Forward,
+                    false,
+                    Upstream::Doh { url, client },
+                    label,
+                )
+            }
+        }
+        numa::config::UpstreamMode::Recursive => {
+            let dummy = Upstream::Udp("0.0.0.0:0".parse().unwrap());
+            (
+                numa::config::UpstreamMode::Recursive,
+                false,
+                dummy,
+                "recursive (root hints)".to_string(),
+            )
+        }
+        numa::config::UpstreamMode::Forward => {
             let upstream_addr = if config.upstream.address.is_empty() {
                 system_dns
                     .default_upstream
@@ -129,10 +168,19 @@ async fn main() -> numa::Result<()> {
                     client,
                 }
             } else {
-        let addr: SocketAddr = format!("{}:{}", upstream_addr, config.upstream.port).parse()?;
+                let addr: SocketAddr =
+                    format!("{}:{}", upstream_addr, config.upstream.port).parse()?;
                 Upstream::Udp(addr)
             };
-    let upstream_label = upstream.to_string();
+            let label = upstream.to_string();
+            (
+                numa::config::UpstreamMode::Forward,
+                config.upstream.address.is_empty(),
+                upstream,
+                label,
+            )
+        }
+    };
     let api_port = config.server.api_port;
 
     let mut blocklist = BlocklistStore::new();
@@ -183,7 +231,7 @@ async fn main() -> numa::Result<()> {
         lan_peers: Mutex::new(numa::lan::PeerStore::new(config.lan.peer_timeout_secs)),
         forwarding_rules,
         upstream: Mutex::new(upstream),
-        upstream_auto: config.upstream.address.is_empty(),
+        upstream_auto,
         upstream_port: config.upstream.port,
         lan_ip: Mutex::new(numa::lan::detect_lan_ip().unwrap_or(std::net::Ipv4Addr::LOCALHOST)),
         timeout: Duration::from_millis(config.upstream.timeout_ms),
@@ -199,8 +247,8 @@ async fn main() -> numa::Result<()> {
         config_dir: numa::config_dir(),
         data_dir: numa::data_dir(),
         tls_config: initial_tls,
-        upstream_mode: config.upstream.mode,
+        upstream_mode: resolved_mode,
-        root_hints: numa::recursive::parse_root_hints(&config.upstream.root_hints),
+        root_hints,
         srtt: std::sync::RwLock::new(numa::srtt::SrttCache::new(config.upstream.srtt)),
         inflight: std::sync::Mutex::new(std::collections::HashMap::new()),
         dnssec_enabled: config.dnssec.enabled,

src/recursive.rs

@@ -65,6 +65,21 @@ pub async fn probe_udp(root_hints: &[SocketAddr]) {
     }
 }
 
+/// Probe whether recursive resolution works by querying root servers.
+/// Tries up to 3 hints before declaring failure.
+pub async fn probe_recursive(root_hints: &[SocketAddr]) -> bool {
+    let mut probe = DnsPacket::query(next_id(), ".", QueryType::NS);
+    probe.header.recursion_desired = false;
+    for hint in root_hints.iter().take(3) {
+        if let Ok(resp) = forward_udp(&probe, *hint, Duration::from_secs(3)).await {
+            if !resp.answers.is_empty() || !resp.authorities.is_empty() {
+                return true;
+            }
+        }
+    }
+    false
+}
+
 pub async fn prime_tld_cache(
     cache: &RwLock<DnsCache>,
     root_hints: &[SocketAddr],

src/system_dns.rs

@@ -2,6 +2,10 @@ use std::net::SocketAddr;
 
 use log::info;
 
+fn is_loopback_or_stub(addr: &str) -> bool {
+    matches!(addr, "127.0.0.1" | "127.0.0.53" | "0.0.0.0" | "::1" | "")
+}
+
 /// A conditional forwarding rule: domains matching `suffix` are forwarded to `upstream`.
 #[derive(Debug, Clone)]
 pub struct ForwardingRule {
@@ -26,10 +30,7 @@ pub fn discover_system_dns() -> SystemDnsInfo {
     }
     #[cfg(target_os = "linux")]
     {
-        SystemDnsInfo {
+        discover_linux()
-            default_upstream: detect_upstream_linux_or_backup(),
-            forwarding_rules: Vec::new(),
-        }
     }
     #[cfg(windows)]
     {
@@ -102,11 +103,7 @@ fn discover_macos() -> SystemDnsInfo {
                 if ns.parse::<std::net::Ipv4Addr>().is_ok() {
                     current_nameserver = Some(ns.clone());
                     // Capture first non-supplemental, non-loopback nameserver as default upstream
-                    if !is_supplemental
+                    if !is_supplemental && default_upstream.is_none() && !is_loopback_or_stub(&ns) {
-                        && default_upstream.is_none()
-                        && ns != "127.0.0.1"
-                        && ns != "0.0.0.0"
-                    {
                         default_upstream = Some(ns);
                     }
                 }
@@ -156,7 +153,7 @@ fn discover_macos() -> SystemDnsInfo {
     }
 }
 
-#[cfg(target_os = "macos")]
+#[cfg(any(target_os = "macos", target_os = "linux"))]
 fn make_rule(domain: &str, nameserver: &str) -> Option<ForwardingRule> {
     let addr: SocketAddr = format!("{}:53", nameserver).parse().ok()?;
     Some(ForwardingRule {
@@ -166,38 +163,100 @@ fn make_rule(domain: &str, nameserver: &str) -> Option<ForwardingRule> {
     })
 }
 
-/// Detect upstream from /etc/resolv.conf, falling back to backup file if resolv.conf
-/// only has loopback (meaning numa install already ran).
 #[cfg(target_os = "linux")]
-fn detect_upstream_linux_or_backup() -> Option<String> {
+const CLOUD_VPC_RESOLVER: &str = "169.254.169.253";
-    // Try /etc/resolv.conf first
+
-    if let Some(ns) = read_upstream_from_file("/etc/resolv.conf") {
+#[cfg(target_os = "linux")]
+fn discover_linux() -> SystemDnsInfo {
+    // Parse resolv.conf once for both upstream and search domains
+    let (upstream, search_domains) = parse_resolv_conf("/etc/resolv.conf");
+
+    let default_upstream = if let Some(ns) = upstream {
         info!("detected system upstream: {}", ns);
-        return Some(ns);
+        Some(ns)
-    }
+    } else {
-    // If resolv.conf only has loopback, check the backup from `numa install`
+        // Fallback to backup from a previous `numa install`
         let backup = {
             let home = std::env::var("HOME")
                 .map(std::path::PathBuf::from)
                 .unwrap_or_else(|_| std::path::PathBuf::from("/root"));
             home.join(".numa").join("original-resolv.conf")
         };
-    if let Some(ns) = read_upstream_from_file(backup.to_str().unwrap_or("")) {
+        let (ns, _) = parse_resolv_conf(backup.to_str().unwrap_or(""));
+        if let Some(ref ns) = ns {
             info!("detected original upstream from backup: {}", ns);
-        return Some(ns);
         }
-    None
+        ns
+    };
+
+    // On cloud VMs (AWS/GCP), internal domains need to reach the VPC resolver
+    let forwarding_rules = if search_domains.is_empty() {
+        Vec::new()
+    } else {
+        let forwarder = resolvectl_dns_server().unwrap_or_else(|| CLOUD_VPC_RESOLVER.to_string());
+        let rules: Vec<_> = search_domains
+            .iter()
+            .filter_map(|domain| {
+                let rule = make_rule(domain, &forwarder)?;
+                info!("forwarding .{} to {}", domain, forwarder);
+                Some(rule)
+            })
+            .collect();
+        if !rules.is_empty() {
+            info!("detected {} search domain forwarding rules", rules.len());
+        }
+        rules
+    };
+
+    SystemDnsInfo {
+        default_upstream,
+        forwarding_rules,
+    }
 }
 
+/// Parse resolv.conf in a single pass, extracting both the first non-loopback
+/// nameserver and all search domains.
 #[cfg(target_os = "linux")]
-fn read_upstream_from_file(path: &str) -> Option<String> {
+fn parse_resolv_conf(path: &str) -> (Option<String>, Vec<String>) {
-    let text = std::fs::read_to_string(path).ok()?;
+    let text = match std::fs::read_to_string(path) {
+        Ok(t) => t,
+        Err(_) => return (None, Vec::new()),
+    };
+    let mut upstream = None;
+    let mut search_domains = Vec::new();
     for line in text.lines() {
         let line = line.trim();
         if line.starts_with("nameserver") {
+            if upstream.is_none() {
                 if let Some(ns) = line.split_whitespace().nth(1) {
-                if ns != "127.0.0.1" && ns != "0.0.0.0" && ns != "::1" {
+                    if !is_loopback_or_stub(ns) {
-                    return Some(ns.to_string());
+                        upstream = Some(ns.to_string());
+                    }
+                }
+            }
+        } else if line.starts_with("search") || line.starts_with("domain") {
+            for domain in line.split_whitespace().skip(1) {
+                search_domains.push(domain.to_string());
+            }
+        }
+    }
+    (upstream, search_domains)
+}
+
+/// Query resolvectl for the real upstream DNS server (e.g. VPC resolver on AWS).
+#[cfg(target_os = "linux")]
+fn resolvectl_dns_server() -> Option<String> {
+    let output = std::process::Command::new("resolvectl")
+        .args(["status", "--no-pager"])
+        .output()
+        .ok()?;
+    let text = String::from_utf8_lossy(&output.stdout);
+    for line in text.lines() {
+        if line.contains("DNS Servers") || line.contains("Current DNS Server") {
+            if let Some(ip) = line.split(':').next_back() {
+                let ip = ip.trim();
+                if ip.parse::<std::net::IpAddr>().is_ok() && !is_loopback_or_stub(ip) {
+                    return Some(ip.to_string());
                 }
             }
         }
@@ -236,10 +295,7 @@ fn detect_dhcp_dns_macos() -> Option<String> {
                     // Take the first non-loopback DNS server
                     for addr in inner.split(',') {
                         let addr = addr.trim();
-                        if !addr.is_empty()
+                        if !is_loopback_or_stub(addr) && addr.parse::<std::net::Ipv4Addr>().is_ok()
-                            && addr != "127.0.0.1"
-                            && addr != "0.0.0.0"
-                            && addr.parse::<std::net::Ipv4Addr>().is_ok()
                         {
                             log::info!("detected DHCP DNS: {}", addr);
                             return Some(addr.to_string());
@@ -278,7 +334,7 @@ fn discover_windows() -> SystemDnsInfo {
         if trimmed.contains("DNS Servers") || trimmed.contains("DNS-Server") {
             if let Some(ip) = trimmed.split(':').next_back() {
                 let ip = ip.trim();
-                if !ip.is_empty() && ip != "127.0.0.1" && ip != "::1" {
+                if !is_loopback_or_stub(ip) {
                     upstream = Some(ip.to_string());
                     break;
                 }
@@ -316,43 +372,6 @@ pub fn match_forwarding_rule(domain: &str, rules: &[ForwardingRule]) -> Option<S
 
 // --- System DNS configuration (install/uninstall) ---
 
-/// Set the system DNS to 127.0.0.1 so all queries go through Numa.
-/// Saves the original DNS settings for later restoration.
-pub fn install_system_dns() -> Result<(), String> {
-    #[cfg(target_os = "macos")]
-    let result = install_macos();
-    #[cfg(target_os = "linux")]
-    let result = install_linux();
-    #[cfg(not(any(target_os = "macos", target_os = "linux")))]
-    let result = Err("system DNS configuration not supported on this OS".to_string());
-
-    if result.is_ok() {
-        if let Err(e) = trust_ca() {
-            eprintln!("  warning: could not trust CA: {}", e);
-            eprintln!("  HTTPS proxy will work but browsers will show certificate warnings.\n");
-        }
-    }
-    result
-}
-
-/// Restore the original system DNS settings saved during install.
-pub fn uninstall_system_dns() -> Result<(), String> {
-    let _ = untrust_ca();
-
-    #[cfg(target_os = "macos")]
-    {
-        uninstall_macos()
-    }
-    #[cfg(target_os = "linux")]
-    {
-        uninstall_linux()
-    }
-    #[cfg(not(any(target_os = "macos", target_os = "linux")))]
-    {
-        Err("system DNS configuration not supported on this OS".to_string())
-    }
-}
-
 // --- macOS implementation ---
 
 #[cfg(target_os = "macos")]
@@ -500,21 +519,25 @@ const SYSTEMD_UNIT: &str = "/etc/systemd/system/numa.service";
 /// Install Numa as a system service that starts on boot and auto-restarts.
 pub fn install_service() -> Result<(), String> {
     #[cfg(target_os = "macos")]
-    {
+    let result = install_service_macos();
-        install_service_macos()
-    }
     #[cfg(target_os = "linux")]
-    {
+    let result = install_service_linux();
-        install_service_linux()
-    }
     #[cfg(not(any(target_os = "macos", target_os = "linux")))]
-    {
+    let result = Err::<(), String>("service installation not supported on this OS".to_string());
-        Err("service installation not supported on this OS".to_string())
+
+    if result.is_ok() {
+        if let Err(e) = trust_ca() {
+            eprintln!("  warning: could not trust CA: {}", e);
+            eprintln!("  HTTPS proxy will work but browsers will show certificate warnings.\n");
         }
+    }
+    result
 }
 
 /// Uninstall the Numa system service.
 pub fn uninstall_service() -> Result<(), String> {
+    let _ = untrust_ca();
+
     #[cfg(target_os = "macos")]
     {
         uninstall_service_macos()
@@ -609,7 +632,7 @@ fn install_service_macos() -> Result<(), String> {
     std::fs::write(PLIST_DEST, plist)
         .map_err(|e| format!("failed to write {}: {}", PLIST_DEST, e))?;
 
-    // Load the service
+    // Load the service first so numa is listening before DNS redirect
     let status = std::process::Command::new("launchctl")
         .args(["load", "-w", PLIST_DEST])
         .status()
@@ -619,14 +642,34 @@ fn install_service_macos() -> Result<(), String> {
         return Err("launchctl load failed".to_string());
     }
 
-    // Set system DNS to 127.0.0.1 now that the service is running
+    // Wait for numa to be ready before redirecting DNS
-    eprintln!("  Service installed and started.");
+    let api_up = (0..10).any(|i| {
+        if i > 0 {
+            std::thread::sleep(std::time::Duration::from_millis(500));
+        }
+        std::net::TcpStream::connect(("127.0.0.1", crate::config::DEFAULT_API_PORT)).is_ok()
+    });
+    if !api_up {
+        // Service failed to start — don't redirect DNS to a dead endpoint
+        let _ = std::process::Command::new("launchctl")
+            .args(["unload", PLIST_DEST])
+            .status();
+        return Err(
+            "numa service did not start (port 53 may be in use). Service unloaded.".to_string(),
+        );
+    }
+
     if let Err(e) = install_macos() {
         eprintln!("  warning: failed to configure system DNS: {}", e);
     }
+
+    eprintln!("  Service installed and started.");
     eprintln!("  Numa will auto-start on boot and restart if killed.");
     eprintln!("  Logs: /usr/local/var/log/numa.log");
-    eprintln!("  Run 'sudo numa service stop' to fully uninstall.\n");
+    eprintln!("  Run 'sudo numa uninstall' to restore original DNS.\n");
+    eprintln!("  Want full DNS sovereignty? Add to numa.toml:");
+    eprintln!("    [upstream]");
+    eprintln!("    mode = \"recursive\"\n");
     Ok(())
 }
 
@@ -708,7 +751,10 @@ fn install_linux() -> Result<(), String> {
             .map_err(|e| format!("failed to create {}: {}", resolved_dir.display(), e))?;
 
         let drop_in = resolved_dir.join("numa.conf");
-        std::fs::write(&drop_in, "[Resolve]\nDNS=127.0.0.1\nDomains=~.\n")
+        std::fs::write(
+            &drop_in,
+            "[Resolve]\nDNS=127.0.0.1\nDomains=~.\nDNSStubListener=no\n",
+        )
         .map_err(|e| format!("failed to write {}: {}", drop_in.display(), e))?;
 
         let _ = run_systemctl(&["restart", "systemd-resolved"]);
@@ -802,17 +848,21 @@ fn install_service_linux() -> Result<(), String> {
 
     run_systemctl(&["daemon-reload"])?;
     run_systemctl(&["enable", "numa"])?;
-    run_systemctl(&["start", "numa"])?;
 
-    eprintln!("  Service installed and started.");
+    // Configure system DNS before starting numa so resolved releases port 53 first
-
-    // Set system DNS now that the service is running
     if let Err(e) = install_linux() {
         eprintln!("  warning: failed to configure system DNS: {}", e);
     }
+
+    run_systemctl(&["start", "numa"])?;
+
+    eprintln!("  Service installed and started.");
     eprintln!("  Numa will auto-start on boot and restart if killed.");
     eprintln!("  Logs: journalctl -u numa -f");
-    eprintln!("  Run 'sudo numa service stop' to fully uninstall.\n");
+    eprintln!("  Run 'sudo numa uninstall' to restore original DNS.\n");
+    eprintln!("  Want full DNS sovereignty? Add to numa.toml:");
+    eprintln!("    [upstream]");
+    eprintln!("    mode = \"recursive\"\n");
     Ok(())
 }