fix(lan): point split-horizon DNS at a second tower address to dodge the router's WiFi filter#480
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…the router's WiFi filter The Vodafone Station drops traffic from WiFi clients to the port-forward target IP (tower, .10) on the forwarded ports (80/443), making every web service unreachable from WiFi. A firmware audit found no setting to lift the filter — but it is keyed to the forward's target IP, not the port: the same services on a second tower address pass fine (verified live from aaron, HTTP 200). - add 192.168.0.11 as a second address on tower's enp11s0 profile - point pi's split-horizon host-records at .11 instead of .10 The port forwards keep targeting .10, so the external path is unchanged. An AAAA/IPv6 approach was tried first and abandoned: the Station advertises no IPv6 default route (and no external v6 exists), and without one macOS/iOS getaddrinfo filters out AAAA answers entirely. Documented in CLAUDE.md. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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Problem
Web services on tower are unreachable from WiFi clients on the home LAN: the Vodafone Station drops traffic from its WLAN to the port-forward target IP (tower,
.10) on the forwarded ports (80/443). A full firmware audit (via its/api/v1) found no setting to lift this — no DMZ/exposed host, no NAT-loopback toggle, and the per-ruleAllInterfacesflag is silently normalized back totrueeven when force-written through the API.Key discovery
The filter is keyed to the forward's target IP, not the port: the identical services on a second tower IPv4 address pass the WLAN bridge fine. Verified live from aaron (WiFi):
.10:443times out,.11:443answers HTTP 200.Change
192.168.0.11/24asaddress2on theenp11s0-staticprofile.host-records at.11..11mechanism, and why AAAA-based split horizon is a dead end on this LAN.The port forwards keep targeting
.10, so the external path is unchanged. Wired clients simply use.11like everyone else.Why not IPv6 (first attempt, abandoned)
An AAAA-based approach worked at the packet level (the Station doesn't filter IPv6 on-link) but fails at the client: the Station advertises SLAAC prefixes with no default route and there is no external IPv6 — and without a v6 default route, macOS/iOS
getaddrinfofilters AAAA answers out entirely (confirmed:digreturned the AAAA,getaddrinforeturned only the A). Plain requests kept timing out.Verification
nix build .#nixosConfigurations.tower.config.system.build.toplevelsucceeds; generated keyfile rendersaddress2=192.168.0.11/24.nix eval .#nixosConfigurations.pi.config.services.dnsmasq.settings.host-recordshows all eight names →.11.ncto.11:80/443OPEN andcurl --resolve test.etiennerobert.com:443:192.168.0.11→ 200; same from pi (wired).After merge + rebuild of both hosts:
sudo systemctl restart NetworkManager-ensure-profiles && nmcli connection up enp11s0-staticon tower (the ensure-profiles oneshot doesn't re-run on switch), then plaincurl -sI https://test.etiennerobert.com/from a WiFi client must answer instantly.🤖 Generated with Claude Code