In short: Reverse DNS maps an IP address back to a hostname using a PTR record. Because the address holder controls the reverse zone, request the change through Virgo Networks if no self-service option is shown.
Choose the hostname
Use a fully qualified hostname such as mail.example.com or server1.example.com. Create the matching forward A or AAAA record first so the hostname resolves to the same address.
Request the PTR record
Open a Technical ticket containing:
- The exact IPv4 or IPv6 address.
- The required fully qualified hostname.
- The service identifier.
- The reason for the change, especially when preparing a mail server.
Verify forward-confirmed reverse DNS
- Look up the address's PTR record and confirm it returns the hostname.
- Look up the hostname's A or AAAA record and confirm it returns the original address.
- Check both IPv4 and IPv6 independently where both send traffic.
Mail servers need more than PTR: The SMTP greeting, forward DNS, reverse DNS, SPF, DKIM and DMARC should form a consistent identity. Reverse DNS alone does not guarantee delivery.
Propagation and old records
Resolvers may cache the earlier PTR until its TTL expires. If an address is reassigned or a hostname retired, request the reverse-DNS change as part of the service change.
