🔄

DNS-Based Failover

Simple

Free preview · 2 of 5 steps

DNS failover: redirect by changing the answer

DNS failover uses DNS itself as the routing layer: when a server is unhealthy, the authoritative DNS simply returns a different IP. Clients automatically connect to the backup server next time they resolve the hostname.

This works because DNS is stateless and time-bounded by TTL. By keeping TTL low (30–60 seconds), failover completes in about a minute.

Packets in motion — click to inspect:

1 / 2

Space to play/pause · ← → to step