- a protocol that uses TCP **port 43** to communicate with public databases.
- The whois tool queries the databases to retrieve domain registration records.
- WHOIS records typically include information such as
- `Name Server`: part of [[DNS 53]] and help translate domain names into IP addresses, directing traffic to the appropriate web server.
- `Registrar`: The company through which the domain name was registered.
- `Administrative Contact`
- `Technical Contact`
- `Creation and Expiration Dates`
- `Domain Status`
```bash
# megacorpone.com 도메인 정보를 192.168.50.251에 있는 WHOIS 서버에 물어봐라 라는 뜻
# -h specifies the host running the WHOIS service
whois $DOMAIN -h $IP
whois megacorpone.com -h 192.168.50.251
# Reverse lookup
whois 38.100.193.70 -h 192.168.50.251
```