DNS and DHCP (needed to replace a dnsmasq-based router):
- router.dns.domain/hosts/overrides/forwardZones: authoritative local
domain, split-horizon host records with reverse entries, wildcard
overrides and per-zone forwarders (private zones skip DNSSEC).
- lans.<n>.dhcp.reservations: Kea host reservations, published in DNS.
- Tunnels with dns = true admit what their peers route, so a
site-to-site peer without a transfer address can use the resolver.
Installer:
- router-install wipes a disk, creates an ESP and an ext4 root and
installs a prebuilt system with its secrets; nothing is built on the
box. installed-layout is the shared disk layout contract.
- lib.mkInstaller builds an ISO for a given nixosSystem;
packages.installer-example is the example's ISO.
Covered by the dns and installer VM tests (the latter installs onto an
empty disk and boots it under UEFI), wireguard DNS and assertion cases.
PLAN.md records the remaining gaps for replacing the hand-written router.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
router.wireguard.<name> configures tunnels through networkd: road warrior
(listening, dual-stack), site-to-site (no transfer network) and provider
dial-out with masquerade. A tunnel has a zone like a LAN, so inter-zone rules
apply; management, DNS and internet are opt-in. Peers' allowedIPs become
routes (destination-based routing; default-route tunnels are rejected).
Tunnels have a kill switch (default on): forwarded packets for their
allowedIPs are dropped if they would leave via an uplink, before the
established-accept so flows that used the tunnel are cut too.
Private keys stay outside the Nix store and are passed to the unprivileged
systemd-networkd with LoadCredential, so key files can be root-only.
Assertions cover CIDR/key/endpoint formats, duplicate allowedIPs, overlaps
with LAN subnets, port and device clashes, and rule destinations inside
tunnel networks. A five-VM `wireguard` check covers road warrior, site-to-site,
the provider tunnel with an IPv6 transfer net, zone rules and the kill switch.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
IPv6: router.wan.ipv6.enable mirrors the existing uplink config (DHCPv6 with
WithoutRA=solicit, delegated prefix). The ISP delegates a single /64, so
exactly one LAN may claim it via router.lans.<name>.ipv6.pd (asserted); other
LANs stay IPv4-only. SLAAC only, no NAT66.
PPPoE: router.wan.ipv4.type = "pppoe" runs pppd on an optional VLAN of the
uplink, with the password read from a file at service start (never the Nix
store). NAT, forwarding and MSS clamping (MTU 1492) use the derived PPP
device; native IPv6 stays on the untagged link.
Tests: basic.nix is parameterised by uplink type; the pppoe variant uses a
fake ISP with pppoe-server (VLAN 7, CHAP). Both variants cover IPv6 PD, SLAAC,
routing without NAT and WAN-deny. Assertion tests gain PD/PPPoE cases and a
full-system evaluation step.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
router.* schema (wan, lans, dns.forwarders) compiled to systemd-networkd,
a generated nftables ruleset with NAT, Kea DHCPv4 and Unbound, plus build-time
assertions against lock-out and interface conflicts.
tests/basic.nix is a three-node VM test (upstream/router/client) covering WAN
DHCP, LAN DHCP and DNS, NAT, WAN-deny and LAN SSH/ping. `nix run .#lab` boots
the same topology in tmux with one console pane per VM and the driver REPL.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
nilsandClaude Sonnet 5.5