rDNS
Technology & Computing abbreviation · Networking
| Stands for | Reverse DNS |
|---|---|
| Categories | Technology & Computing |
rDNS stands for Reverse DNS, a networking abbreviation.
Looks up the hostname associated with an IP address, the opposite of a normal DNS lookup. Mail servers check rDNS to judge whether a sending server is legitimate, and logging tools use it to show readable names instead of numbers.
Example: Our outbound mail was rejected because the server's IP had no rDNS entry.
Usage notes
Whoever owns the IP block, usually the ISP or hosting provider, controls its reverse DNS, so changes must be requested from them rather than made at the domain registrar. "Forward-confirmed" reverse DNS, where the hostname resolves back to the same IP, is a common anti-spam test. Traceroute output uses rDNS names, which often reveal router locations.
Related abbreviations
More networking abbreviations
- PPPoE – Point-to-Point Protocol over Ethernet
- PPTP – Point-to-Point Tunneling Protocol
- PSK – Pre-shared key
- PTR – Pointer (record)
- QoS – Quality of service
- QUIC – QUIC (originally Quick UDP Internet Connections)
- RDP – Remote Desktop Protocol
- RFC – Request for Comments
- RIP – Routing Information Protocol
- RIR – Regional internet registry
- RTT – Round-trip time
- SAN – Storage area network