Highlights Cloudflare: The benefits of serving stale DNS entries when using Consul Cloudflare faced an issue with long latencies for DNS responses in certain parts of the world. In addition DNS over TLS is also a factor. They use Unbound as a DNS resolver. For a better failover, they set 30 seconds TTL for such responses. There are two options to solve this problem. The first is prefetching. This means that on each request TTL is checked.