Knowledgebase

Useful DNS Testing Tools (Firstserv Guide)

The Domain Name System (DNS) is what connects your domain name to your website, email, and other services. Correct DNS configuration ensures everything works as expected—but troubleshooting DNS issues can sometimes be tricky.

This guide highlights some useful external tools to help you check whether your DNS is set up correctly.

Important Note

The tools listed below are third-party services and are not affiliated with Firstserv. However, they are widely used and helpful for diagnosing DNS issues.

Tool 1: IntoDNS (General DNS Health Check)

🔗 https://intodns.com

What it does:

• Provides a full DNS health report
• Checks:
  • Nameservers (NS records)
  • Mail servers (MX records)
  • General DNS configuration

How to Use

1. Enter your domain name (e.g. yourdomain.com)
   • ✅ Do NOT include www or subdomains
2. Click Report

Understanding Results

• ✅ Blue → Everything looks correct
• ⚠️ Yellow → Minor warnings (usually OK but worth reviewing)
• ❌ Red → Issues that may need fixing

Tool 2: WhatsMyDNS (Propagation Checker)

🔗 https://www.whatsmydns.net

This tool helps you check DNS propagation worldwide.

What is DNS Propagation?

When you make DNS changes:

• Your DNS records are updated
• Changes take time to spread across global DNS servers
• This process is called propagation

⏱️ It can take up to 24–48 hours

How to Use

1. Enter your domain name
2. Select the record type to check:
   • NS → Nameservers
   • A → Website IP address
   • MX → Email routing
3. Click Search

What You’ll See

• A global map of DNS results
• ✔️ Green ticks show updated records
• ❌ Red crosses indicate old or missing data

✅ This helps you see how far your DNS changes have propagated

Important Tip

• Test servers may query your domain for the first time
• Your local ISP may still cache older DNS data

👉 This is normal during propagation

Best Practice: Reduce TTL Before Changes

Before making major DNS updates (e.g. migrating hosting):

What is TTL?

• TTL (Time To Live) defines how long DNS records are cached

Recommended Settings

• Default TTL is often:

  86400 seconds (24 hours)
  

• Reduce to:

  300–3600 seconds (5 minutes–1 hour)
  

When to Change TTL

• ✅ Lower TTL at least 24 hours before making changes
• ✅ After migration completes, increase TTL back to normal

Why This Helps

• Faster propagation
• Less downtime
• Quicker switch to new servers

Summary

• DNS tools help diagnose configuration and propagation issues
• IntoDNS → General DNS and mail health
• WhatsMyDNS → Global propagation checker
• Lowering TTL before changes ensures smoother migrations

Need Help?

If you’re unsure how to interpret DNS results or need help fixing an issue, the Firstserv support team is always happy to assist.