Show HN: Korbinsky – A Reverse DNS API

2 points by pgCKIN 4 years ago | 2 comments

Hello HN,

over the last few weeks for an internal project we (CKIN) have been building Korbinsky, an API allowing to retrieve which hostnames corresponds to a given IP. Coming from a different background (security and embedded software) this has been an interesting journey tackling various techs and we see no reason not to open (a moderate) usage to developers. We have created a key for HN so you can start to experiment without registration (which is of course free and available [0]):

curl -v -H "apikey: l86WRM0NC2bBHMfEBQdkhXbDp2BoQw0O" http://ko.ckin.it/api/v1/ip/2620:0:862:ed1a::1

of course it works also with other IP addresses :) even the good old IPv4:

curl -v -H "apikey: l86WRM0NC2bBHMfEBQdkhXbDp2BoQw0O" http://ko.ckin.it/api/v1/ip/91.198.174.192

there is a quota associated to the key so if you intend to build something it would be better to register your own (or ping us in case of different quota needs).

thank you in advance for your precious feedback.

Best regards, CKIN

[0] https://ko.ckin.it/registration/

gnyman 4 years ago |

I'm not an expert on DNS so I might be missing some important part, but why use this instead of a normal reverse dns lookup?

That is, `dig PTR 192.174.198.91.in-addr.arpa` or calling `gethostbyaddr`?

pgCKIN 4 years ago | |

Thank you for asking! Your question is the demonstration that "A Reverse DNS API" is a very subpar tagline. As you correctly state, for "reverse DNS" usually we mean the PTR, which, not being a requirement for a working internet, is quite neglected. Few are sets, and those in large part are actually just an indication of which ISP or datacenter they belong. What we try to do with Korbinsky is to provide information about hostnames actually pointing to a given IP address or just hosted there.

Just to give an example: $ dig +short PTR 159.241.75.51.in-addr.arpa

ns3131293.ip-51-75-241.eu.

$ curl -H "apikey: l86WRM0NC2bBHMfEBQdkhXbDp2BoQw0O" http://ko.ckin.it/api/v1/ip/51.75.241.159

["petitbambou.com"]

I hope this clarify, and I hope, one day, to come up with a more explicative tagline.