On Mon, Oct 14, 2013 at 10:01 PM, Barry Shein <bzs@world.std.com> wrote:
This would be a lot of work, so nobody does it. If someone asks for the rdns for: 2001:0db8:85a3:0042:1000:8a2e:0370:7334 it's a lot of work for example.com to return something like: 2001-0db8-85a3-0042-1000-8a2e-0370-7334.example.com ?
No... it's not a lot of work; the problem is, it's maybe worth even less than the amount of work involved though. What piece of information is being expressed there that would not be expressed by a NXDOMAIN response? Assuming the user is residential ".example.com" pertains to the ISP, not the hostname at that IP address. The ISP's info is accessible via services such as WHOIS-RWS How about some wildcard PTR record ? *.3.a.5.8.8.b.d.0.1.0.0.2.ip6.arpa PTR unnamedhost.example.com. It's equally useless; and conveys equally limited information about the host. However, at least it doesn't generate spurious records that are just (IP repeated).(domain) -- -JH