01
What happens after a domain is typed
A device asks a recursive resolver, which may answer from cache. Otherwise it follows referrals from root servers to the relevant top-level-domain servers and then to the authoritative nameserver for the domain.
The authoritative answer is cached according to its TTL. This reduces repeated work but means old answers can remain visible for a period after a change.
02
Common DNS records
A and AAAA records point names to IPv4 and IPv6 addresses. CNAME records alias one name to another. MX records route email, while TXT records carry verification and email-protection policies such as SPF, DKIM and DMARC.
NS records identify authoritative nameservers. CAA records can restrict which certificate authorities may issue certificates for the domain.
- A / AAAA: web server address
- CNAME: hostname alias
- MX: email delivery
- TXT: verification and mail policy
- NS: authoritative DNS
- CAA: certificate issuance policy
03
Propagation and safe changes
DNS propagation is not one global switch. Resolvers update cached answers at different times, and local devices may retain data too. Lowering TTL in advance can help planned migrations, but repeatedly changing records makes diagnosis harder.
Export the current zone, identify website and email dependencies, change only the required record and keep rollback information. Changing nameservers replaces responsibility for the whole zone and can interrupt email if records are not recreated.
04
DNS reliability and security
Protect registrar and DNS-provider accounts with strong unique credentials and MFA. Restrict who can edit records and record changes.
DNSSEC can provide authenticity for DNS answers when correctly supported across the chain. It does not encrypt DNS requests or make the hosted website secure.
Practical next steps
Checklist
- 01Export existing records
- 02Confirm the authoritative provider
- 03Identify website and email dependencies
- 04Use MFA
- 05Change one planned item at a time
- 06Verify web, email and certificate services
- 07Keep rollback values
Common questions
Questions and answers
How long do DNS changes take?
Some appear within minutes; cached answers can last until their TTL expires, and resolver behaviour varies.
Can DNS changes break email?
Yes. Incorrect MX or TXT records, or incomplete nameserver migrations, can disrupt delivery and authentication.
Is a domain the same as DNS?
No. The domain is the registered name; DNS publishes instructions for services using that name.
What does TTL mean?
Time to live tells resolvers how long an answer may be cached before it should be refreshed.
Need a considered recommendation?
Discuss the website, not just the symptom.
AHANIX reviews each requirement manually. Technical recommendations may depend on access to the website, hosting or DNS configuration.
Continue learning