port 43

The network port used by the original WHOIS (glossary)WHOIS The legacy lookup service for domain registration data, now replaced by RDAP for gTLDs. Full definition of WHOIS protocol. A program connects to a server on this port, sends a domain name (glossary)domain name A readable internet name made of labels separated by dots. Full definition of domain name and gets back plain text. Since 28 January 2025, gTLD (glossary)gTLD generic top-level domain A top-level domain not tied to a country, run under ICANN contracts. Full definition of gTLD registries (glossary)registry The central database and system of a top-level domain, or loosely the organization that runs it. Full definition of registry and registrars (glossary)registrar A company that registers domain names for customers with the registry. Full definition of registrar no longer have to run it, except for .com, .name and .post, though many ccTLDs (glossary)ccTLD country code top-level domain A top-level domain for a country or territory, usually two letters long. Full definition of ccTLD still do.