OmitDefaultRegions=true leaves no DERP fallback if custom node fails
warningavailabilityUpdated Mar 2, 2026(via Exa)
Technologies:
How to detect:
With OmitDefaultRegions: true in derpMap ACL, if custom DERP node becomes unreachable, clients have no relay fallback and cannot establish connections when direct peer-to-peer fails
Recommended action:
Use OmitDefaultRegions: false to retain Tailscale default DERP regions as fallback. Test custom node selection with tailscale netcheck. Monitor node reachability and latency to ensure custom node is preferred when available