Pierre-Olivier Mercier
6b6a8c847f
Enable Goldmark block-level attributes so the relearn `children` shortcode applies its CSS classes instead of printing them literally in the table-of-contents pages. Also expand the deploy, plugins, records, and email reference docs and add the checks pages.
2.9 KiB
| date | author | title | description | weight | aliases |
|---|---|---|---|---|---|
| 2021-01-12T21:38:49+02:00 | Frederic | SOA (Start Of Authority) | Understand the Start Of Authority record, the mandatory record at the apex of every DNS zone, and how happyDomain manages it for you. | 10 | records/SOA |
The Start Of Authority (SOA) record is defined by RFC 1035. It is mandatory and unique: exactly one SOA must sit at the apex (the root) of every DNS zone. Its presence declares that the name server is authoritative for the zone and carries the parameters that govern how the zone is replicated between servers and cached by resolvers.
Fields of the SOA record
The SOA record gathers seven values:
| Field | Description |
|---|---|
| MNAME (primary name server) | The hostname of the primary (master) name server for the zone. |
| RNAME (responsible party) | The email address of the person responsible for the zone, encoded in DNS form: the @ is replaced by a dot (for example hostmaster.example.com. means hostmaster@example.com). |
| Serial | A version number for the zone. It must increase every time the zone changes, so that secondary servers know they need to transfer the new content. |
| Refresh | How often (in seconds) a secondary server checks the primary for an updated serial. |
| Retry | How long (in seconds) a secondary waits before retrying a failed refresh. |
| Expire | How long (in seconds) a secondary keeps serving the zone when it cannot reach the primary, before considering the data stale. |
| Minimum (negative-cache TTL) | The duration for which resolvers cache negative answers (NXDOMAIN), per RFC 2308. |
The SOA in happyDomain
happyDomain does not present the SOA as a standalone record to edit field by field. Instead, the apex of your zone is modelled as an Origin service, which groups the SOA together with the zone's name servers (NS records). You will therefore find the SOA at the root of your domain, alongside the list of authoritative name servers, rather than in a separate form.
The serial is, in most cases, handled automatically. When you publish your changes, many DNS providers manage the serial themselves: happyDomain detects this capability and re-reads the zone after publication to reflect the serial the provider actually assigned. You normally do not need (nor are you expected) to set it by hand.
{{% notice style="info" title="What you can and cannot change" %}} The exact behaviour depends on your DNS provider. Some providers expose the full SOA and let happyDomain submit its values; others manage the SOA serial — and sometimes the other timers — on their side. When the provider takes care of the serial, any value happyDomain shows for it simply reflects the published state and is refreshed automatically. {{% /notice %}}
For more on how the apex and other groupings are represented, see the {{< relref "../services" >}} chapter.