Knowledgebase

Understanding DNS Propagation (Firstserv Guide)

When you make changes to your DNS (such as updating an IP address or pointing your domain to a new server), those changes are applied instantly on Firstserv nameservers. However, it can take some time before the changes are visible across the internet.

Why Does DNS Take Time to Update?

Each DNS record has a Time To Live (TTL) value. This tells other systems how long to cache (store) DNS data before checking for updates.

• Typical TTL: 14400 seconds (4 hours)
• Some records: up to 86400 seconds (24 hours)

⏱️ As a result, DNS changes can take anywhere from a few minutes to up to 24 hours to fully propagate.

Additional Caching Layers

The delay is often extended because DNS is cached in multiple places:

• 🖥️ Your computer (Windows/Mac)
• 🌐 Your web browser
• 📡 Your router/modem
• 🌍 Your ISP (internet provider)

Each of these may continue to serve older DNS data until their cache refreshes.

How to See Changes Faster

✅ Option 1: Restart Your Devices (Quick & Effective)

A simple but effective solution:

1. Turn off your router/modem
2. Shut down your computer or device
3. Wait a few minutes
4. Power everything back on

✅ This clears many local caches and often resolves the issue.

✅ Option 2: Use Alternative DNS Servers

You can bypass your ISP’s DNS cache by using third-party DNS providers:

• Cloudflare:

  • 1.1.1.1
  • 1.0.0.1

• Google:

  • 8.8.8.8
  • 8.8.4.4

✅ Configure these on your device or router for faster DNS updates.

Clearing Your Local DNS Cache

Clearing your DNS cache forces your device to fetch fresh DNS data.

Windows

1. Open Command Prompt as Administrator
2. Run:

✅ You should see:

Successfully flushed the DNS Resolver Cache

macOS

1. Open Terminal
2. Run the appropriate command for your version:

Modern macOS (Yosemite 10.10.4 and newer):

Older versions:

• macOS 10.7–10.9:

• macOS 10.5–10.6:

⚠️ You may be prompted to enter your administrator password.

Important Notes

• Clearing your DNS cache is different from clearing your browser cache
• Router or ISP-level caching may still delay updates
• Full propagation across global networks can take up to 24 hours

Summary

• DNS changes are applied instantly on Firstserv servers
• Propagation delays are caused by caching systems
• You can speed things up by:
  • Restarting devices
  • Using third-party DNS servers
  • Flushing your local DNS cache

If you’re unsure whether DNS changes have fully propagated or need help troubleshooting, the Firstserv support team is always available to assist.