Adds section documenting the redundant subnet router architecture:
both netinfra-01 and netinfra-02 now advertise 192.168.0.0/22 for
automatic failover. This fixes the SPOF where all remote monitoring
(Uptime Kuma on Cloudron VPS) routed through netinfra-01 alone —
any DERP bounce or Docker LinkChange event took down visibility to
every LAN host simultaneously.
Also documents the resolv.conf immutable flag fix on netinfra-01
(chattr -i) that was preventing tailscaled from updating DNS config
after every link change event.
[#377]
mrcharles
75e229c0ab