4 ms·

Why not just... whois example.com Or is this also intended to be a domain discovery tool?

by ryannevius 9y ago

arca_vorago 9y ago
In which case why not 'dig' or 'nslookup' too?
- greyface- 9y ago
  There is one odd case where asking DNS won't work accurately: if a domain is registered but has no nameservers.
  - toast0 9y ago
    Almost always, you need to provide nameservers when you register a domain. host -t NS example.org should return something, even if the listed nameservers don't exist, don't respond for that domain, or return NXDomain.
  - anh79 9y ago
    Can you give some example? I have tried some registrars and if you don't provide some NS information, the default NS information is used. I have a tool in the past https://gist.github.com/icy/b30893cecc8ec657317ba93831b0fd4a#file-whoisvn-sh-L70 https://gist.github.com/icy/b30893cecc8ec657317ba93831b0fd4a... it works fine as I experience. The tool has option `--all` to check by using both google/open dns. E.g, $ whoisvn google-is-good.com --all opendns.org: google-is-good.com available googledns: google-is-good.com available $ whoisvn google-is-bad.com --all opendns.org: google-is-bad.com available googledns: google-is-bad.com available
    - teddyh 9y ago
      Look at, for example, "nmu360.se". It is registered, but has no name servers configured.
      - feelin_googley 9y ago
        echo nmu360.se|exec nc -vvn 91.226.37.83 43
      - marcosdumay 9y ago
        Whois says it has no name server (what a weird format that of .se), but digg finds an A record with 92.242.140.20 (what seems to be a register IP).
        teddyh 9y ago
        Let me guess: Your ISP is injecting fake DNS responses.
      - anh79 9y ago
        Very good example. Thanks a lot.
  - _jomo 9y ago
    Isn't there always an SOA record?
    - teddyh 9y ago
      No. If there are no name servers, there isn’t a zone, and if there isn’t a zone, there is no SOA record.
anh79 9y ago
whois may not work if you don't have correct configuration (e.g, whois server for some special domains .info, .social, ...)
- teddyh 9y ago
  Use a proper whois command which has all this configured. Note: may be difficult to achieve on macOS.
  - anh79 9y ago
    It's even hard on Linux machine. How do you know all whois servers for different top level domains? for .info, for .social, for .in, bla bla. In 2016 it's so painful to set up correct whois monitoring at my company . (May be it's a lot better now.)
    - teddyh 9y ago
      apt install whois

Why not just... whois example.com Or is this also intended to be a domain discovery tool?

arca_vorago 9y ago

In which case why not 'dig' or 'nslookup' too?

greyface- 9y ago
There is one odd case where asking DNS won't work accurately: if a domain is registered but has no nameservers.
- toast0 9y ago
  Almost always, you need to provide nameservers when you register a domain. host -t NS example.org should return something, even if the listed nameservers don't exist, don't respond for that domain, or return NXDomain.
- anh79 9y ago
  Can you give some example? I have tried some registrars and if you don't provide some NS information, the default NS information is used. I have a tool in the past https://gist.github.com/icy/b30893cecc8ec657317ba93831b0fd4a#file-whoisvn-sh-L70 https://gist.github.com/icy/b30893cecc8ec657317ba93831b0fd4a... it works fine as I experience. The tool has option `--all` to check by using both google/open dns. E.g, $ whoisvn google-is-good.com --all opendns.org: google-is-good.com available googledns: google-is-good.com available $ whoisvn google-is-bad.com --all opendns.org: google-is-bad.com available googledns: google-is-bad.com available
  - teddyh 9y ago
    Look at, for example, "nmu360.se". It is registered, but has no name servers configured.
    - feelin_googley 9y ago
      echo nmu360.se|exec nc -vvn 91.226.37.83 43
    - marcosdumay 9y ago
      Whois says it has no name server (what a weird format that of .se), but digg finds an A record with 92.242.140.20 (what seems to be a register IP).
      - teddyh 9y ago
        Let me guess: Your ISP is injecting fake DNS responses.
    - anh79 9y ago
      Very good example. Thanks a lot.
- _jomo 9y ago
  Isn't there always an SOA record?
  - teddyh 9y ago
    No. If there are no name servers, there isn’t a zone, and if there isn’t a zone, there is no SOA record.

anh79 9y ago

whois may not work if you don't have correct configuration (e.g, whois server for some special domains .info, .social, ...)

teddyh 9y ago
Use a proper whois command which has all this configured. Note: may be difficult to achieve on macOS.
- anh79 9y ago
  It's even hard on Linux machine. How do you know all whois servers for different top level domains? for .info, for .social, for .in, bla bla. In 2016 it's so painful to set up correct whois monitoring at my company . (May be it's a lot better now.)
  - teddyh 9y ago
    apt install whois