alt Hacker NewsOne of the craziest aspects of IPv6 implementation is the reverse DNS lookups.
IPv6 uses ip6.arpa and segments each little nybble into a subdomain!
https://en.wikipedia.org/wiki/Reverse_DNS_lookup#IPv6_revers...
This means there are always 32 octets to a reverse-IPv6 address, and there are no shortcuts or macros to overcome this! That means if you wish to assign a singular name that maps from a legitimate /64 Network ID, you must populate 64 bits worth of octets in a zone with this data. It is an absurd non-solution. This never should've been allowed to happen, but it will basically mean that ISPs abandon reverse DNS entirely when they migrate to IPv6 implementations.
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Anyone who's ever had to delegate DNS authority on anything other than an 8-bit boundary can understand the value of that feature.
At face value, yeah, that's replacing "8" with "4," but from a practical perspective, delegating authority for a customer IPv4 /25 requires, at minimum, 128 records. (Granted, there's also no practical need to be stingy about IPv6 allocations -- that IPv4 /25 customer could simply receive an IPv6 /48.)
I would firmly expect to see a lot more formulaic reverse (and presumably forward) DNS responses, where needed, since filling files with records you need to store on disk (and in memory) doesn't scale well. The tech has existed for years; I wrote my own implementation years ago, but these days I'd use something like PowerDNS with https://github.com/wttw/regexdns .
I agree it's a pain to read, mostly because DNS addresses are written backwards, but an "absurd non-solution"? For a set of instructions that don't even depend on the format of the record (they work for v4 too), and which I could describe in one line in a HN comment?
If this is the craziest part of v6 then it must be incredibly well designed overall.