SynergyCP rDNS Package#
About#
The rDNS package lets Administrators and Clients manage reverse DNS (PTR) records for their IP space directly from SynergyCP, and keeps a DNS provider of your choice — PowerDNS, Cloudflare, or a SynergyCP-managed BIND server — in sync automatically.
A PTR record maps an IP address back to a hostname. Receiving mail servers routinely perform a reverse DNS lookup on the sending IP and check that the returned hostname resolves back to the same address (forward-confirmed reverse DNS); servers without valid rDNS often have their mail rejected. Hosting providers therefore need a way to let each customer set the PTR records for their own IPs — that is what this package provides.
Features#
- Per-server management — a dedicated Reverse DNS page for every server, in both the admin and client portals, listing IPv4 addresses individually and IPv6 records per address.
- IPv4 and IPv6 — full support for both address families, including
ip6.arpazones. - Client self-service with guardrails — clients can only manage PTRs for IP entities assigned to their servers, client-entered hostnames must pass a forward-DNS check, and client-created IPv6 records are capped by a configurable limit.
- Automatic provider sync — every create, change, and delete is pushed to the configured DNS provider by background jobs with retries; failures are logged where admins can see them.
- Zone file import — migrate from an existing DNS server by importing BIND-style reverse zone files, including bulk multi-zone dumps.
- Provider migration — re-sync every stored record to a newly configured provider with one command.
- Search — find PTRs by full or partial IP address (either family) or by hostname.
- Cleanup on decommission — wiping a server or deleting an IP entity removes its PTR records from SynergyCP and from the DNS provider.
Supported DNS providers#
| Provider | IPv4 | IPv6 | Notes |
|---|---|---|---|
| Cloudflare | Yes | Yes | Recommended — fully managed, no DNS server to host. Zones are created automatically. |
| PowerDNS v4 | Yes | Yes | Self-hosted option. Installer available. |
| PowerDNS v3 | Yes | No | Deprecated upstream; existing installations only. |
| SynergyCP API (BIND) | Yes | No | Legacy SynergyCP-managed BIND server. |
How it works#
SynergyCP stores every PTR record in its own database and treats the DNS provider as a downstream copy. When a record is created, changed, or deleted, a background job pushes the change to the provider configured in Settings > DNS. Jobs retry with backoff if the provider is temporarily unreachable, and write an admin-visible log entry if all retries are exhausted, so a flaky DNS server never silently loses changes. All PTR activity (who changed what, and to which value) appears in the SynergyCP logs.
Because SynergyCP keeps the authoritative copy, you can switch DNS providers at any time and replay every record to the new one.
Requirements#
- rDNS package 3.x requires SynergyCP 5.4.0 or later. Earlier panels can run package 2.x.
- A supported DNS provider (see table above). The PowerDNS and BIND options require a separate server to host the DNS service; Cloudflare does not.
In this section#
- Setup — install a DNS provider, connect it to SynergyCP, and verify it works.
- Managing PTR Records — the per-server Reverse DNS page (admin and client) and the global rDNS PTRs list.
- Importing Zone Files — migrate records from an existing DNS server.
- Migrating Between Providers — move to a different DNS provider without losing records.
- Troubleshooting — common errors and how to resolve them.