Under the hood

When you add a new domain, OneDollarDNS kicks off an automated discovery phase. Rather than asking you to manually list every hostname, the system probes a curated list of common subdomains and dynamically expands based on what it finds.

The discovery process checks the following:

• Common hostnames: @ (apex), www, mail, api, app, admin, blog, cdn, staging, dev, and more
• MX record targets (mail servers often have their own DNS records)
• NS record targets (authoritative nameservers)
• CNAME targets that point back to the same domain (followed recursively)

Only hostnames that return at least one DNS record are saved as monitored hosts. The domain view shows a discovering indicator while this process runs. Once complete, monitoring begins immediately.

After discovery, each domain is checked on a recurring schedule. By default, domains are checked every hour. Enabling the Frequent Monitoring add-on lets you reduce this to as low as every 5 minutes.

Every monitoring run queries the domain's authoritative nameservers directly, bypassing cached responses and ensuring you always see the current state of your DNS records as they exist at the source.

OneDollarDNS monitors all of the following DNS record types for every host:

After each DNS lookup, the results are saved as a snapshot — a point-in-time record of every value and TTL returned. This snapshot is then compared against the previous one for the same host.

Three types of changes are detected:

Each detected change produces a DNS alert that appears in the dashboard and triggers a notification.

You can trigger an immediate check at any time from the domain detail page by clicking Check now. This queues a DNS lookup for all hosts in the domain regardless of whether a host is marked as Priority. Useful right after making intentional DNS changes to confirm they've propagated correctly.

If a host wasn't found during automated discovery, you can add it manually. Custom hosts are monitored on the same schedule as auto-discovered ones. If a manual host returns no DNS records at all, it remains in the list but shows as pending until records are found.

You can also remove any host — auto-discovered or manual — at any time from the domain page.

If you already have a BIND-format zone file for your domain, you can use it to populate your monitored host list in bulk instead of adding hosts one at a time. Zone file import is available in two places:

• During domain creation — attach a zone file in the Add domain dialog. Hosts are imported immediately after the domain is created.
• From the domain detail page — click Upload zone file next to the Add host button at any time.

The parser understands standard BIND zone file syntax, including:

• $ORIGIN and $TTL directives
• Multi-line records using parentheses
• Relative and absolute (FQDN) owner names
• Whitespace-inherited owner names (continuation lines)

SOA records and wildcard entries (*) are skipped automatically, as are any out-of-zone names that don't belong to the domain being imported. Hosts that already exist are not duplicated — if a host was previously auto-discovered, importing it via zone file removes the auto-discovered label and treats it as an explicit host going forward.

Each imported label is queued for DNS resolution in the background. The zone file must be no larger than 512 KB.