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ButlerianJihadyesterday at 6:54 PM1 replyview on HN

Again, absolutely blind to the management of these things at scale. Yeah, I don't rightly care about "how easy it is" to generate them. You can't even comprehend or convey the massive number of records and zones that are involved in managing a network of devices that all require dynamic updates to reverse-DNS and add/update/remove device addresses on a regular basis.

DNS is a distributed database system, and so the challenge is not cramming in data with a brainless script, but managing how that data is distributed and accessed by thousands or millions of peer servers, caches, and clients worldwide.

IPv4 reverse-DNS was quite simple when it was broken on octet boundaries and there were only four of those boundaries in total. But even then, ISPs could often not be arsed to put the right data in there. Some left it blank and some waited until they were forced, by strict requirements that said reverse must match forward DNS in many cases.

I have never found any user-accessible software, not on any Linux distribution or on any cloud service, that would permit an ordinary consumer to manage even a /24 IPv4 network's reverse-DNS at scale, or programmatically, as opposed to by-hand "copy paste" as has been so condescendingly suggested here. There are plenty of hosted DNS providers, and there are plenty of monkey-brain Dashboard interfaces where you can pound out one A record at a time. But there was nothing to deal with dynamic addressing or DNS databases at scale. That's why IPv6's reverse DNS remains an absurd non-solution.


Replies

Dagger2yesterday at 10:18 PM

So... how many records and zones? I'm pretty sure I could convey it if I could work out what you were talking about.

You went from "you can't even comprehend or convey the massive number of records and zones that are involved" to one v4 /24, managed "at scale" but by an ordinary consumer, who you expect to be capable of programming. This is a bit all over the place.

It's not any harder to deal with v6 reverse DNS than it is v4. In fact, making every reverse label 4 bits instead of 8, combined with v6 being much bigger than v4, makes rDNS much easier to deal with in v6 because you can generally delegate reverse zones on exactly the same boundaries that you delegate the corresponding IP blocks. In v4, you often need to delegate on boundaries that aren't /8, /16 and /24 and it suddenly gets more annoying.

Scaling up for rDNS is no different to scaling up for forward DNS. It's a well-understood problem.