An SOA Record (Start of Authority Record) is a special DNS record that contains administrative information about your DNS zone. It identifies the primary nameserver for the domain and includes settings used for DNS synchronization and caching.
Every DNS zone should have one SOA record.
The SOA record helps DNS servers understand:
Which nameserver is the primary authority for the zone
Who is responsible for the domain DNS
When the zone was last updated
How often secondary DNS servers should check for updates
How long DNS resolvers should cache certain responses
A typical SOA record includes:
Field | Meaning |
|---|---|
Primary Nameserver | Main authoritative DNS server |
Responsible Email | Admin contact (formatted in DNS style) |
Serial Number | Zone version number |
Refresh | How often secondary servers check updates |
Retry | Retry interval after failed refresh |
Expire | When secondary data becomes invalid |
Minimum TTL | Default negative caching / TTL value |
yourdomain.com. 3600 IN SOA ns1.provider.com. admin.yourdomain.com.
(
2026042901 ; Serial
3600 ; Refresh
1800 ; Retry
1209600 ; Expire
3600 ) ; Minimum TTL