Discover WAN via ddns:<host> then trace:<url> before listen. Persist to
self_ip.json. Previous addresses stay denied for keep_previous. Failure
keeps the last known set. /healthz reports age and source.
Single Fetcher.Fetch on the Guard that holds DenyPrefixes. skipTlsVerification
is ignored. No 502. keys add writes the secret only to --out. Release binary
has no -test-allow-prefix.
Block 6to4/Teredo/NAT64-local/site-local/benchmarking/reserved
ranges from the IANA registries (families, not decoded embeds).
Guard.DenyPrefixes / -deny-prefix covers hairpin WAN /32s; home
addresses stay on-box, not in git. Control is tcp/tcp4/tcp6 only.
Go service with /healthz, SSRF guard (parse + resolve-all + Control),
exhaustive tests, NixOS module, and Makefile as source of truth for
build flags. nix flake check runs make test lint.
kyle