IANA Registries

The Internet Assigned Numbers Authority (IANA) maintains the official registries for port numbers, protocol numbers, and hundreds of other internet protocol parameters. These are the authoritative sources.

Service Names and Port Numbers

65,535+ entries

The complete list of TCP/UDP port assignments – all 65,535 ports across all protocols.

https://www.iana.org/assignments/service-names-port-numbers

Protocol Numbers

256 entries

IP protocol numbers used in the Protocol field of IPv4 and Next Header field of IPv6 (e.g., 6=TCP, 17=UDP, 1=ICMP).

https://www.iana.org/assignments/protocol-numbers

HTTP Status Codes

63 registered codes

Official registry of HTTP response codes, including which RFC defined each code.

https://www.iana.org/assignments/http-status-codes

HTTP Field Names (Headers)

200+ headers

All registered HTTP header field names with their defining specifications.

https://www.iana.org/assignments/http-fields

DNS Resource Record (RR) Types

100+ record types

All DNS record types – A, AAAA, MX, CNAME, TXT, NS, SOA, PTR, SRV, and more.

https://www.iana.org/assignments/dns-parameters

URI Schemes

300+ schemes

Registered URI scheme names: https, http, ftp, mailto, tel, urn, and hundreds more.

https://www.iana.org/assignments/uri-schemes

IANA is operated by ICANN (Internet Corporation for Assigned Names and Numbers). All registries linked above are the normative source – not mirrors or summaries.