[dns-operations] check if a domain has been registered via DNS

[Peng Yonghua]

在 2017/4/27 下午10:03, John Levine 写道:
> If the domain exists in the DNS, it's in use, but if the domain
> doesn't exist in the DNS, it may be available or it may not.  There
> are many states that aren't available but don't publish NS records.

yes there are some cases as you said.

for example, the domain below can't be registered this time, but it has 
no DNS delegation.

Domain Name: CLOUDWEBDNS.COM
    Registrar: GANDI SAS
    Sponsoring Registrar IANA ID: 81
    Whois Server: whois.gandi.net
    Referral URL: http://www.gandi.net
    Name Server: NS5.CLOUDWEBDNS.COM.DELETED.GANDI.NET
    Name Server: NS6.CLOUDWEBDNS.COM.DELETED.GANDI.NET
    Status: clientHold https://icann.org/epp#clientHold
    Status: clientTransferProhibited 
https://icann.org/epp#clientTransferProhibited
    Status: redemptionPeriod https://icann.org/epp#redemptionPeriod