SOA Record
The SOA (start of authority) record names a zone’s primary nameserver and holds its serial number and refresh, retry, and expiry timers. This lookup reads that record so you can confirm a zone change was published and see how long errors are cached.
When to use this: You changed DNS and want to confirm the zone serial moved, or secondary nameservers seem out of date. Command prefix soa:
About the SOA Record
Read the Start of Authority record: primary nameserver, admin contact, serial number and the refresh, retry, expire and negative-cache timers.
FAQ
- What is the serial for?
- Secondary nameservers compare it to decide whether to fetch the zone again; it must increase on every change.
- What is the minimum field?
- Today it sets how long resolvers cache “name does not exist” answers (negative caching).