Deno long-running process retains stale DNS entries beyond TTL

Goal

Determine whether Deno's DNS resolution cache in long-running server processes respects record TTL values or retains entries indefinitely.

Constraints and uncertainty

Deno's underlying Rust networking stack manages DNS caching, but cache duration is not consistently documented across Deno APIs. Behavior may differ between Deno versions due to Rust implementation changes, and network stack behavior varies significantly across operating systems. Third-party modules may implement additional caching layers without respecting Deno's permission boundaries.

Questions

1. Does Deno's standard library provide any programmatic mechanism to flush or invalidate the DNS cache at runtime?
2. How does the cache behave when a resolved IP address changes due to DNS failover or load-balancer rotation?
3. Are there documented version-specific differences in cache TTL handling between Deno 1.x and 2.x releases?