The Domain Name System (DNS) connects domain names to servers and services. When a website does not load after moving hosts, emails fail to arrive or a verification record is not detected, DNS is often involved. DNS lookup tools let you check what records exist for a domain and whether changes have propagated.
Common DNS Record Types
| — | — | — |
|---|---|---|
| A | Points a domain to an IPv4 address | Website hosting |
| AAAA | Points to an IPv6 address | Modern hosting |
| TXT | Text information | SPF, DKIM, DMARC, site verification |
When to Use DNS Lookup Tools
- After moving to a new host
- When setting up a CDN
- Configuring email services
- Verifying domain ownership for Search Console or other services
- Troubleshooting SSL certificate issues
- Checking email authentication records
How to Perform a DNS Lookup
- Open a DNS lookup tool or use command-line tools like nslookup or dig
- Enter your domain name
- Choose the record type to check
- Review the returned values and compare them with expected settings
DNS Propagation
When you change DNS records, resolvers around the world may continue using cached old values until their TTL (time to live) expires. Propagation checkers show results from multiple global locations, helping you understand whether changes have spread.
Email Authentication Records
| — | — |
|---|---|
| SPF (TXT) | Lists servers allowed to send email for your domain |
| DKIM (TXT/CNAME) | Adds a digital signature to emails |
| DMARC (TXT) | Tells receivers how to handle failing emails and sends reports |
Correct authentication improves deliverability and protects against spoofing.
Troubleshooting Examples
| — | — |
|---|---|
| Emails going to spam | Check SPF, DKIM and DMARC |
Safety Tips
- Note existing records before making changes
- Change one thing at a time
- Lower TTL before planned migrations
- Avoid deleting email records unintentionally
Common Mistakes
- Editing DNS at the wrong provider (check NS records first)
- Duplicate SPF records
- Typos in TXT records
- Forgetting the www record
Frequently Asked Questions
How long does DNS propagation take?
Often minutes to hours, sometimes up to 48 hours.
Where do I manage DNS?
At your DNS provider, shown by your domain’s NS records.
Can DNS affect SEO?
Indirectly; misconfigurations can cause downtime or migration problems.
What is TTL?
Time to live, how long resolvers cache a record.
Conclusion
DNS lookup tools help you see how a domain is configured and diagnose common website and email problems. Learn the main record types, check changes carefully and allow time for propagation.
