sysadmin/ReverseDNSCleverness written at 22:18:25; Add Comment
The excessive cleverness of some people's reverse DNS
I have to say that I'm bemused by the amount of effort that people will
go to just to avoid coming up with hostnames for their machines. (This
is different from the lazy people, who just don't bother creating
By now I am used to the people who carefully give their IP addresses a PTR record of the IP address itself:
(Naturally these show up as invalid reverse DNS, since there is no corresponding A record.)
I see enough of these that my tool for doing reverse DNS lookups prints them specially. I'm never sure if these are deliberate or just the result of a well intentioned person being told that all of their IP addresses should have PTR records, whether or not they have hostnames.
Recently, though, someone did this one better: they gave their IP
addresses PTRs to themselves in the .in-addr.arpa zone and then
gave them corresponding A records; the result was entirely valid
(Also, I would be remiss if I didn't give an honorable mention to as15444.net, a domain that is named after their ASN.)
* * *
Atom feeds are available; see the bottom of most pages.