DNS APUs

Two PC Engines APU2 boxes (apu01 / apu02) run Unbound as a household anycast recursive resolver at **10.53.53.53**. FRR advertises that address over OSPF to the CCR2116 core, which ECMP-hashes clients onto whichever APUs are currently advertising. This book is the operator view: architecture, the anycast self-heal that closes the Sep 2026 OSPF-Full / empty-FIB blackholes, and the HOST-APU-01 listen map plus how the hp02 dashboard still scrapes metrics after Prometheus and node_exporter moved to localhost.