What Is DNS Cache?

Why It Matters

DNS caching makes the internet faster by avoiding redundant DNS lookups. But when you change DNS records — like pointing your domain to Domain Forward — caching means the change doesn’t take effect everywhere instantly.

This is why DNS propagation takes time. Old cached records must expire before new ones are used.

How It Works

DNS caching happens at multiple levels:

Cache Level	Location	Duration
Browser cache	Chrome, Firefox, etc.	Usually 1-2 minutes
OS cache	Your computer’s resolver	Controlled by TTL
ISP resolver	Your internet provider	Controlled by TTL
Public resolver	Google (8.8.8.8), Cloudflare (1.1.1.1)	Controlled by TTL

When you visit example.com:

1. Browser checks its cache → not found
2. OS checks its cache → not found
3. ISP resolver checks its cache → found! Returns cached A record
4. No query to the authoritative nameserver needed

DNS Cache and Domain Forwarding

When you set up Domain Forward and change your DNS records:

• Before change: DNS cache has your old A record (pointing to old server)
• After change: New A record points to Domain Forward’s server
• During propagation: Some visitors hit the old cache (old server), others get the new record (Domain Forward)
• After TTL expires: All caches are updated, all visitors reach Domain Forward

Tips for Faster Propagation

1. Lower your TTL before making changes — set it to 300 seconds (5 minutes) a day before
2. Flush your local cache to test immediately
3. Use whatsmydns.net to check propagation globally
4. Be patient — ISP caches may ignore low TTLs