Port 433 — nnsp

Well-known port 433 (tcp/udp): NNTP for transit servers (NNSP). Service name: nnsp. Referenced in RFC3977.

port kind port status standard verification verified tier A iana-registry-row@1

registry record

value: 433

references: RFC3977

Service Name	nnsp
Port Number	433
Transport Protocol	tcp
Description	NNTP for transit servers (NNSP)
Assignee	[IESG]
Contact	[IETF_Chair]
Registration Date
Modification Date	2018-07-06
Reference	[RFC3977]
Service Code
Unauthorized Use Reported
Assignment Notes

source: https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.csv
version: IANA registry, Last-Modified: Fri, 29 May 2026 01:11:28 GMT
retrieved: 2026-05-29 · updated: 2026-05-29

agent: curl -H 'accept: application/json' wire.phall.io/port/433 or /port/433.json