DNS (Domain Name System) translates domain names into IP addresses and vice versa. DNS records determine where a domain directs traffic, where email is stored, and which services are used. Configuration errors can make a website unavailable or cause email to be lost.
You can check a domain's DNS records using DNS Lookup on rechecker.ru.
Main record types
| Type | Purpose |
|---|---|
| A | IPv4 address |
| AAAA | IPv6 address |
| CNAME | Alias for another domain |
| MX | Mail servers |
| TXT | Arbitrary text (verification, SPF, DKIM) |
| NS | Authoritative DNS servers for the domain |
| SOA | Zone parameters |
| SRV | Services (for example, SIP, XMPP) |
| CAA | Permitted certificate authorities |
A record
Maps a domain or subdomain to an IPv4 address.
example.com. A 93.184.216.34
www A 93.184.216.34Format: имя TTL класс тип значение
| Field | Description |
|---|---|
| name | Domain or subdomain (blank = root) |
| TTL | Time to live in seconds (3600 = 1 hour) |
| class | Usually IN (Internet) |
| type | A |
| value | IPv4 address |
Example for the root and www:
@ A 93.184.216.34
www A 93.184.216.34AAAA record
The IPv6 equivalent of an A record.
example.com. AAAA 2606:2800:220:1:248:1893:25c8:1946CNAME record
An alias: the name points to another domain. The browser resolves the CNAME and gets the final A/AAAA record.
www CNAME example.com.
blog CNAME cname.vercel-dns.com.Limitations:
- A CNAME should not point to another CNAME in the same chain (although this is technically possible)
- A CNAME for the root (@) is not recommended — use A/AAAA or the provider's ALIAS/ANAME
- A CNAME cannot be used alongside other records for the same name (MX, TXT, etc.)
MX record
Specifies the mail servers for a domain.
example.com. MX 10 mail.example.com.
example.com. MX 20 mail2.example.com.Priority (10, 20) — a lower value is preferred. The mail record with priority 10 is used first.
TXT record
Arbitrary text. Used for:
- Domain verification (Google, Yandex)
- SPF (list of permitted sending servers)
- DKIM (email signing key)
- DMARC (email handling policy)
example.com. TXT "v=spf1 include:_spf.google.com ~all"Long values are split into multiple lines in quotation marks (some DNS providers combine them automatically).
NS record
Specifies the authoritative DNS servers for a zone:
example.com. NS ns1.registrar.com.
example.com. NS ns2.registrar.com.When changing hosting or DNS providers, change the NS records at the registrar. After changing the NS records, wait for DNS propagation.
SOA record
A zone's administrative record: primary NS, administrator's email, serial number, and refresh timings.
example.com. SOA ns1.example.com. admin.example.com. (
2025030701 ; serial
3600 ; refresh
600 ; retry
86400 ; expire
3600 ; minimum TTL
)SRV record
Specifies the host and port for a service:
_service._proto.example.com. SRV priority weight port target
_sip._tcp.example.com. SRV 0 5 5060 sip.example.com.CAA record
Restricts which certificate authorities can issue SSL certificates for a domain:
example.com. CAA 0 issue "letsencrypt.org"
example.com. CAA 0 issuewild "letsencrypt.org"Common configurations
Website on a single server
@ A 93.184.216.34
www CNAME example.com.Website on a CDN (Cloudflare)
@ A 192.0.2.1 ; proxy IP Cloudflare
www CNAME example.com.Website + email on Google Workspace
@ A 93.184.216.34
www CNAME example.com.
@ MX 5 alt1.aspmx.l.google.com.
@ MX 10 aspmx.l.google.com.
@ TXT "v=spf1 include:_spf.google.com ~all"Subdomain on an external service (Vercel, Netlify)
blog CNAME cname.vercel-dns.com.TTL for different scenarios
| Scenario | Recommended TTL |
|---|---|
| Stable configuration | 3600–86400 |
| Before changing DNS | 300–600 (faster updates) |
| Critical records | 60–300 |
Checking DNS
dig example.com A
dig example.com MX
dig example.com TXT
nslookup example.comOnline: DNS Lookup — check all record types from different servers.
Learn more about DNS optimization: DNS and performance: optimization for websites.