How is the admin email formatted in an SOA record?

The '@' symbol is replaced by a period. For example, hostmaster@example.com is written as hostmaster.example.com.

What is the zone serial number in an SOA record?

The serial number is an incrementing revision number (often formatted as YYYYMMDDNN) used by secondary nameservers to know when the zone has been updated.

How do I view a domain's SOA record?

Query the SOA record with our online DNS Lookup tool or run 'dig SOA example.com' in terminal.

Home/DNS Lookup/SOA Record

NS PTR

DNS Resource Record Type

SOA Record: Start of Authority Record

Declares core administrative zone metadata, primary nameserver, admin contact email, and zone serial number.

Record Type

SOA

Query Protocol

DNS Port 53

Standard / RFC

RFC 1035, Section 3.3.13

Recommended TTL

86400 seconds

Query Live SOA Records

Query any domain name to inspect authoritative SOA records, response latency, and TTL values.

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BIND Zone File Syntax

Standard BIND representation of this record in authoritative master zone files:

example.com. 86400 IN SOA ns1.example.com. hostmaster.example.com. ( 2026100301 7200 3600 1209600 3600 )

Recommended TTL: 86400 seconds (24 hours).

Common Configuration Pitfalls

Forgetting to increment the serial number when modifying zone files, causing secondary DNS servers to ignore new updates.
Using an unescaped '@' symbol in the admin email field (email addresses use a dot instead, e.g. admin.example.com for admin@example.com).

How the SOA Record Operates in DNS Resolution

The SOA (Start of Authority) record marks the beginning of every authoritative DNS zone file. It contains critical metadata: the primary authoritative nameserver (MNAME), the zone administrator's email address (RNAME), the zone serial revision number (used for secondary zone transfers), and refresh, retry, and expire timers.

Explore Other DNS Record Types

Frequently Asked Questions

Technical answers and configuration advice for DNS SOA records.

The Start of Authority (SOA) record is the master record of a DNS zone containing admin contact details, zone serial number, and zone transfer timing parameters.