To the best of my knowledge there are two types of PTR/A Records. For dailup prefixes, IPs used for DSL,Cable, etc PTR should be generated and contain the IP to make it easier to block emails from that ranges. For v6 prefixes you will probably want to do this programmatically with e.g. powerdns (see createReverse in https://doc.powerdns.com/authoritative/lua-records/functions.html)... Doing 2**96 PTR records in Textfile is "impractical" dig -x 2003:d6:cf31:8c00:b67a:f1ff:fedd:1d12 2.1.d.1.d.d.e.f.f.f.1.f.a.7.6.b.0.0.c.8.1.3.f.c.6.d.0.0.3.0.0.2.ip6.arpa. 86400 IN PTR p200300d6cf318c00b67af1fffedd1d12.dip0.t-ipconnect.de. For hosts I prefer nameing conventions which contain exact enough locations which helps debugging. Just try mtr ns-com.ui-dns.com to see which locations and routers it passes inside AS8560. So for an accepoint the nameing convention should at least identify the building and floor where it is installed, for switches the exact rack and for routers the exact datacenter. "Just" using IATA 3 letter airport codes is not good enough in my opinion because you usally have multiple datacenters/CoLos/PoPs around a bigger airport like MCI or FRA Cheers Thomas Am 11.02.25 um 18:13 schrieb Joel Sommers:
Hello all -
I am a researcher at Colgate University, working with colleagues at the University of Wisconsin and Boston University on studying aspects of the DNS.
We are wondering what insights anyone here may be willing to share about naming convention patterns that we’ve observed. There are many FQDNs with (full or partial) embedded IPv4 addresses in A records, with many variations on padding, order, whether decimal or hex, etc. There are also a number of providers that use some alphanumeric sequence (seemingly unrelated to IP address) embedded in names. We assume that these names are generated either from a commercial IPAM system or some other set of management tools or scripts. Some of our questions are:
* What kinds of knobs are available in commercial IPAM systems for crafting hostname patterns? * What are some of the key use cases for having an A record (or AAAA for that matter) in which part or all of the address is embedded in the name?
Thanks so much for any thoughts you’re willing to share -- please feel free to respond off-list.
Regards,
Joel Sommers