How to use RDAP to replace WHOIS and WHOIS2 protocols

The domain industry is going through a generational change to Registration Data Directory Services (RDDS) moving from the WHOIS protocol dating from 1982 to a modern JSON based protocol called RDAP. The term WHOIS is almost certain to outlive the protocol of its name and be applied to the equivalent data that comes from RDAP.

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WHOIS replacement

WHOIS has well documented limitations, such as those listed by ICANN:

• No standardised format.
• Inability to authenticate users.
• Lookup-only ability and no search support.
• Lack of standardised redirection or reference.
• No standardised way of knowing what server to query.
• Inability to authenticate the server or encrypt data between server and client and therefore inherently insecure.

If you are a WHOIS user the time has come to upgrade utilise an RDAP client to consume RDDS data. There are a variety of RDAP clients around including both web and command line options, here are just a few to get started:

1. Nominet Lookup is available at rdap.nominet.uk
2. ICANN Lookup is available at lookup.icann.org
3. A range of other RDAP clients, including for the command line are documented at https://rdap.rcode3.com/client_implementations/index.html

If you programatically utilise WHOIS, then you should look at utilising the RDAP standard instead.

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WHOIS2 replacement

WHOIS2 was designed to allow a registrar to offer web based registration data query services for their customers on a centralised website.

It was an extension to WHOIS protocol where the registrar that was authorised to utilise it would pass through the IP address of the third-party querying the domain on the registrars website via what was otherwise a copy of the WHOIS protocol. The quotas of lookups were then applied to the pass-through IP address rather than the registrars IP address.

As the RDAP protocol works over HTTPS the service is queried direct from a web browser, a website must trigger an RDAP query direct from a users browser and not centralise checks. This ensures there is no need for variable quotas and the limits are applied to all IP addresses and subnets equally.

A website owner is in full control of the output they supply to their users; and whether that looks like traditional WHOIS or it takes a more modern approach.

You can find out more about RDAP here.

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