Start of Authority record
DNS & Records
DNS Lookup Every DNS record for any domain A Record Lookup IPv4 addresses for a domain AAAA Record Lookup IPv6 addresses for a domain MX Lookup Mail servers for a domain NS Lookup Authoritative name servers TXT Lookup TXT records, SPF, verification CNAME Lookup Canonical name (alias) records SOA Lookup Start of Authority record SRV Lookup Service location records CAA Lookup Which CAs may issue certificates Reverse DNS (PTR) IP address to hostname DNSSEC Check Is the domain signed and validated? DNS Health Check A full delegation & DNS report cardEmail Deliverability
SPF Check Validate your Sender Policy Framework record DMARC Check Inspect and grade your DMARC policy DKIM Check Find and validate your DKIM public key Blacklist Check Check an IP against email blocklists (DNSBLs) SMTP Test Connect to a mail server and check STARTTLS MTA-STS Check Enforced TLS policy for inbound mail BIMI Check Brand logo record for email TLS-RPT Check SMTP TLS reporting policyNetwork & Web
SSL Certificate Check Inspect a site's TLS certificate and expiry HTTP Header Check Inspect response headers, redirects and security Ping (TCP) Reachability and latency over TCP Port Check Which common ports are openDomain
WHOIS Lookup Registration data for domains, IPs and ASNsThe SOA (Start of Authority) record holds administrative information about a DNS zone: the primary name server, the responsible contact, the zone serial number and the timers that control replication and caching. Every zone has exactly one SOA record, and it sits at the top of the zone as the authority marker for everything beneath it.
An SOA record packs several fields. The MNAME names the primary master name server for the zone. The RNAME is the administrator's email, written with a dot instead of the @ sign. The serial is a version number that secondaries watch to detect updates. Then come four timers: refresh (how often secondaries check for changes), retry (how long to wait after a failed check), expire (when a secondary stops answering if it cannot reach the primary), and the minimum, which sets the negative-caching TTL for nonexistent records.
IPeek shows the zone's SOA: its primary name server, the responsible contact, the current serial, and the refresh, retry, expire and minimum timers. Check that the primary name server matches your DNS provider. The serial is most useful for confirming a change has gone live — a common convention is YYYYMMDDnn, so a recent date means the zone was edited recently. Unusually short or long timers can hint at replication or caching problems. The minimum value tells resolvers how long to cache negative (NXDOMAIN) answers.
The serial number is how secondary name servers know when to pull a fresh copy of the zone. On each refresh interval a secondary compares its stored serial against the primary's; if the primary's is higher, it transfers the updated zone. This means you must increment the serial every time you edit the zone, or secondaries will keep serving stale data. Forgetting to bump it is a classic cause of changes appearing on the primary but not on backup servers. Most providers and tools increment it automatically.
The serial is a version number for the zone that secondary name servers use to detect changes. When you edit the zone you increment the serial; on the next refresh, secondaries compare serials and pull a new copy if the primary's is higher. Forgetting to increment it leaves secondaries serving outdated records.
These SOA timers govern zone replication. Refresh is how often a secondary checks the primary for updates, retry is how long it waits before trying again after a failed check, and expire is when a secondary stops answering entirely if it cannot reach the primary. They keep secondary servers in sync and prevent them from serving badly outdated data.
The SOA record marks the start of authority for a zone and carries the single source of administrative truth: the primary server, contact, serial and timers. Because a zone has one authoritative origin, it has exactly one SOA, placed at the zone apex. Multiple SOA records would be contradictory and invalid.
RNAME is the email address of the person or team responsible for the zone, written in DNS form with the @ replaced by a dot. For example, admin@example.com appears as admin.example.com. To read it, convert the first dot back to an @. It tells you whom to contact about the zone's configuration.
Because the serial increments with each zone edit, checking it tells you whether your change has been published. Many zones use a YYYYMMDDnn serial, so a current date indicates a recent update. After making a change, look up the SOA and confirm the serial advanced, then verify secondaries report the same value.