1.2.0

Adds an optional, advanced feature to actively prevent the IPv6 default-route loss instead of only detecting/repairing it — built on the host-side pf filter proven over a 48h A/B test (0 losses, ndp -rn collapsed from 8 routers to 1).

New: RA Protection (advanced, opt-in)

• What it does: blocks incoming IPv6 Router Advertisements on your primary interface except from the real gateway, removing the multi-RA trigger of the default-route bug. The existing detect-and-repair stays active as a safety net regardless.
• Hidden by default — only offered when your network actually shows the risk pattern (multiple RA senders, or a prior recorded route loss).
• Requires a one-time setup: a small privileged helper (Scripts/ipv6monitor-pf) installed to /Library/PrivilegedHelperTools plus a narrow sudoers rule (fixed subcommands only — never broad pfctl access). See Scripts/README-ra-protection.md for the exact steps.
• Safety built in: an explicit confirm step before arming (shows the detected gateway and freshness), a live progress indicator during detection, pings the gateway before and after arming and auto-reverts if it becomes unreachable, continuous health monitoring that auto-disarms if the filter stops helping (gateway RAs stop arriving, the interface changes, or the rule disappears externally), a menu-bar status line with an always-available one-click Off, and an optional "re-arm on launch" setting that re-validates before ever applying anything automatically.
• Fully German-localized, matching the rest of the app.

Note

The bundled app is ad-hoc signed (no paid Apple Developer account). On first launch you may need to right-click → Open, or remove the quarantine attribute. Building from source (see README) is equally supported.