A concurrent forward and reverse DNS hostname lookup and diagnostic utility for Linux system administrators. A lightweight Linux alternative to NirSoft FastResolver for performing parallel A, AAAA, and PTR hostname lookups across server inventories, web server logs, and local network administration tasks.

Key features:

• Queries forward (A, AAAA) and reverse (PTR .in-addr.arpa / .ip6.arpa) DNS records concurrently via a configurable worker thread pool with per-query round-trip latency (RTT ms) timing.
• Supports system resolvers from /etc/resolv.conf alongside public and custom DNS servers (1.1.1.1, 8.8.8.8, 9.9.9.9, 208.67.222.222, or custom UDP/TCP endpoints) with automatic TCP fallback on truncated responses.
• Cross-references local /etc/hosts entries and kernel /proc/net/arp neighbor cache records together with /proc/net/route gateway diagnostics for LAN troubleshooting.
• Renders query resolution breakdowns and DNS wire latency histograms, and exports structured CSV and JSON lookup reports.

Disclaimer: This project is an independent open-source tool and is not affiliated with, sponsored by, or endorsed by NirSoft or Nir Sofer.