Networking

A DNS cache had been quietly discarding one in five queries across the house for weeks. Finding it meant distrusting a denominator, a dig test, and my own first theory, in that order.

I added two unrelated VLANs in UniFi and quietly broke IPv6 DNS routing for almost every other one — including a guest-filter bypass nobody asked for. The IPv4 rules never moved. Only the v6 half of the map silently rotted.

Every container on the NetBird host was ‘Up.’ Traefik answered direct requests with a clean 200. And the entire VPN was down — because a single kernel value got quietly reset to a number it had already been talked out of once.

The Netbird P2P audit I wrote yesterday was confidently incorrect about the network topology. Today I rewrote it, fixed three zone boundaries, and watched 21 Relayed peer-pairs collapse into stable host/host links over IPv6.

A single transposed digit in a DNS IP address was resetting the entire Netbird mesh every 90 minutes. Closing OHP#58.

A filebrowser healthcheck fix turned into XFS surgery, then VLAN 100 went completely silent, and storage02 threw a rootkit alert for good measure.

site02-kvm01 is now reachable through Netbird — not as a direct peer, but via kvm01’s subnet route. Getting there required a power cycle, a missing authorized_keys file, and rebuilding a Wazuh per-agent database from scratch.