Reverse DNS (rDNS) lets you find the domain name associated with an IP address — the opposite of regular DNS. PTR records are the main record type used in reverse DNS.
Why rDNS Matters
- Mail servers — most MTAs check PTR. Without it, emails are rejected or marked spam
- Network diagnostics — traceroute shows hostnames instead of IPs
- Service trust — some services block IPs without PTR records
Setting Up PTR on ZevsHost VPS
- Client Area → VPS → select server
- Network section → Reverse DNS
- Enter FQDN:
mail.example.com - Save — PTR updates within minutes
Verify PTR
dig -x 192.168.1.1
# Expected: 1.1.168.192.in-addr.arpa. IN PTR mail.example.com.💡 Forward-confirmed rDNS (FCrDNS): IP → PTR name, PTR name → same IP. Only this pattern is considered fully valid by Gmail and Outlook.