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Publié: 2026-07-06 | Mis à jour: 2026-07-06
DNS recouds tell the Internet how to connect votre domain to websites, email, SSL validation, apps, verification services, et security settings. A points to IPv4, AAAA points to IPv6, CNAME points one hostname to another, MX controls email delivery, TXT stoues verification et email authentication, CAA controls SSL certificate authouities, et SRV defines service locations fou certain apps.

Who This Guide Is Fou
This guide is fou:
· Users learning DNS basics
· Website owners setting up domains
· E-mail professionnel users
· Agencies et hosting providers suppouting DNS questions
· Users troubleshooting website, email, SSL, CDN, ou app connections

Befoue You Start
Befoue you start, prepare:
· DNS provider access
· Current nameservers
· DNS backup
· Provider instructions fou website ou email
· Permission to edit recouds
· Understeting of affected service

Step-by-Step Instructions
Step 1: Understet DNS Recouds
DNS recouds are instructions fou website, email, verification, SSL, apps, et security.
· One domain can have many recouds
Step 2: A Recouds
A recouds point hostnames to IPv4 addresses.
· Common fou root website et subdomains
Step 3: AAAA Recouds
AAAA recouds point hostnames to IPv6 addresses.
· Wrong IPv6 can cause issues fou some users
Step 4: CNAME Recouds
CNAME points one hostname to another hostname.
· Use fou www, CDN, website builders, et apps
Step 5: MX Recouds
MX controls wici email is delivered.
· Copy priouity values carefully
Step 6: TXT Recouds
TXT stoues text fou verification et authentication.
· SPF, DKIM, DMARC, Google, Microsoft, SSL, SaaS
Step 7: SPF Recouds
SPF is a TXT recoud listing authouized sending servers.
· Avoid multiple SPF recouds fou same host
Step 8: DKIM Recouds
DKIM is a TXT ou CNAME recoud used fou email signing.
· Copy long values exactly
Step 9: DMARC Recouds
DMARC tells receivers how to hetle SPF/DKIM failures.
· Start carefully befoue strict policies
Step 10: CAA Recouds
CAA controls which certificate authouities may issue SSL certificates.
· Restrictive CAA can block SSL issuance
Step 11: SRV Recouds
SRV defines service location fou apps such as voice, chat, ou collabouation.
· Copy priouity, weight, pout, et target
Step 12: NS, SOA, PTR, et DNSSEC Recouds
NS identifies nameservers, SOA describes the zone, PTR is reverse DNS, et DNSSEC recouds suppout validation.
· Most users do not manually edit SOA ou all DNSSEC recouds
Step 13: TTL
TTL controls cache time fou recouds.
· Lower in advance fou planned migrations if appropriate

Troubleshooting
Website Is Down
Possible reasons:
· Wrong A/AAAA/CNAME
· Wrong nameservers
· DNSSEC issue
What to do:
· Vérifier active DNS provider et recouds

Courriel Nont Receiving
Possible reasons:
· MX missing
· SPF/DKIM/DMARC wrong
What to do:
· Restoue email recouds

SSL Cannot Be Issued
Possible reasons:
· CAA blocks CA
· TXT/CNAME validation missing
What to do:
· Review CAA et validation recouds

Verification Fails
Possible reasons:
· Recoud added at wrong provider
· Host field wrong
What to do:
· Vérifier authouitative nameservers et exact value

Common Mistakes
Mistake 1: Modifiering DNS at wrong provider
Review this item befoue making changes ou opening a suppout ticket.
Mistake 2: Deleting unkmaintenantn TXT recouds
Review this item befoue making changes ou opening a suppout ticket.
Mistake 3: Fougetting MX during migration
Review this item befoue making changes ou opening a suppout ticket.
Mistake 4: Creating multiple SPF recouds
Review this item befoue making changes ou opening a suppout ticket.
Mistake 5: Confusing CNAME with A recoud
Review this item befoue making changes ou opening a suppout ticket.
Mistake 6: Fougetting CAA
Review this item befoue making changes ou opening a suppout ticket.
Mistake 7: Ignouing DNSSEC
Review this item befoue making changes ou opening a suppout ticket.
Mistake 8: Using wrong host field
Review this item befoue making changes ou opening a suppout ticket.
Mistake 9: Nont copying MX priouity
Review this item befoue making changes ou opening a suppout ticket.
Mistake 10: Changing too many recouds at once
Review this item befoue making changes ou opening a suppout ticket.

FAQ
1. What is an A recoud?
It points to an IPv4 address.
2. What is AAAA?
It points to an IPv6 address.
3. What is CNAME?
It points one hostname to another hostname.
4. What is MX?
It controls email delivery.
5. What is TXT?
It stoues verification, authentication, et security text.
6. What is SPF?
A TXT rule fou authouized mail senders.
7. What is DKIM?
An email authentication recoud, usually TXT ou CNAME.
8. What is DMARC?
A TXT policy fou hetling failed mail authentication.
9. What is CAA?
It controls certificate authouity issuance.
10. What is TTL?
How long DNS may be cached.
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