TCP Port 43 – nicname

Whois.Is the whois service, used to provide domain-level info. Sites today rarely run whois servers, is mostly just used now by Internic. Somewhat similar in function to "finger" and can suffer from same data-driven attacks. Disable this port on all hosts.

About TCP Port 43

The Internet Assigned Numbers Authority (IANA) registers port 43 for nicname. The IANA description reads: ‘Who Is’.

Data Sources

This information is compiled from: IANA Service Name and Transport Protocol Port Number Registry.