.arpa, rDNS and a few magical ICMP hacks

The internet’s dusty attic just got a rave review. A hobbyist scored a rare prize: their ISP delegated them a slice of the .arpa universe—the behind‑the‑scenes “reverse phonebook” that maps IP addresses back to names. That’s usually gatekept by big providers, so the community lit up. One camp is starry‑eyed: “super interesting,” cheered a history buff, loving the ARPANET roots. Newcomers are buzzing, with one home‑server hopeful saying this gave them “ideas for nonsense to implement,” basically translating to: time to tinker. Meanwhile, the old guard rolled in with receipts. A veteran calmly dropped that reverse delegation (RFC 2317)—aka letting smaller networks manage their own entries—has been the normal way for ages, and that it took years to catch on. Translation for non‑nerds: you can either let your provider name your IPs or do the naming yourself via clever workarounds. The subtext drama? DIY control vs. ISP defaults. Fans cheered the rare personal win, while experts reminded everyone there’s a “right” way it’s been done. Jokes flew about “temporary fixes” lasting forever, echoing the post’s vibe, and folks linked to projects like Project SERVFAIL and the author’s beloved ISP bgp.wtf. Add a sprinkle of “magic ICMP” mystique and you’ve got peak nerd cinema: starstruck beginners, lore‑dropping veterans, and a legacy domain refusing to die.