Bulk Reverse DNS (PTR)

If you run your own IP blocks, reverse DNS (PTR records) usually means one record per IP — tedious by hand. PrimeDNS has three tools for this, all on the reverse zone's Records page.

1. Create the reverse zone

In Zones, use Add Reverse DNS Zone. Enter your subnet in CIDR notation (e.g. 203.0.113.0/24); PrimeDNS calculates the in-addr.arpa (or ip6.arpa) zone name for you. Classless delegations (anything smaller than a /24, e.g. /26 or /28, per RFC 2317) get a dash-notation zone name and a CNAME block automatically — you don't need to work out the RFC 2317 naming yourself.

After creating the zone, point the delegation NS records at your IP block provider (Hurricane Electric, RIPE, or your upstream ISP) to PrimeDNS's nameservers, same as for a forward zone.

2. Bulk import from CSV

Open the reverse zone's Records page and use Import PTR (CSV). Paste or upload a CSV of ip,hostname pairs — up to 500 rows per import.

203.0.113.10,host1.example.com
203.0.113.11,host2.example.com
203.0.113.12,mail.example.com

3. Generate by pattern (CIDR sweep)

For a block where hostnames follow a predictable pattern, use CIDR sweep instead of a CSV. Give it a hostname pattern with {ip} (full IP, dashed) or {last} (last octet) placeholders and it generates one PTR per address in the range.

# pattern: host-{last}.example.com
# 203.0.113.10 -> host-10.example.com
# 203.0.113.11 -> host-11.example.com

4. Auto-generate from existing A/AAAA records

If you already have forward A/AAAA records and just want matching PTRs, use Auto from A/AAAA. It scans your forward zones (up to 50 zones, 500 records per run) and creates one PTR per IP. If two hostnames share the same IP, only one PTR is created and the duplicate is reported — a PTR can only point one way.

Verify

dig @ns1.primedns.net -x 203.0.113.10 +short

Or via the API, creating a single PTR record directly:

curl -X POST https://api.primedns.net/v1/dns/records \
  -H "X-API-Key: pdns_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" \
  -H "Content-Type: application/json" \
  -d '{
    "domain_name": "113.0.203.in-addr.arpa",
    "name": "10",
    "type": "PTR",
    "content": "host1.example.com.",
    "ttl": 3600
  }'