Networking reference
TCP & UDP Port Numbers – Service & Protocol Lookup
Search the complete IANA service-name and port-number registry by port, protocol, service, assignee or RFC, including TCP, UDP, SCTP, DCCP and unqualified entries.
| Port | Protocol | Service | Description | Assignee | Registration date | Reference/RFC | Status | Record details |
|---|---|---|---|---|---|---|---|---|
| 191 | TCP | prospero | Prospero Directory Service | B. Clifford Neuman | — | — | Assigned | → |
| 191 | UDP | prospero | Prospero Directory Service | B. Clifford Neuman | — | — | Assigned | → |
| 192 | TCP | osu-nms | OSU Network Monitoring System | Doug Karl | — | — | Assigned | → |
| 192 | UDP | osu-nms | OSU Network Monitoring System | Doug Karl | — | — | Assigned | → |
| 193 | TCP | srmp | Spider Remote Monitoring Protocol | Ted J. Socolofsky | — | — | Assigned | → |
| 193 | UDP | srmp | Spider Remote Monitoring Protocol | Ted J. Socolofsky | — | — | Assigned | → |
| 194 | TCP | irc | Internet Relay Chat Protocol | Jarkko Oikarinen | — | — | Assigned | → |
| 194 | UDP | irc | Internet Relay Chat Protocol | Jarkko Oikarinen | — | — | Assigned | → |
| 195 | TCP | dn6-nlm-aud | DNSIX Network Level Module Audit | — | — | — | Assigned | → |
| 195 | UDP | dn6-nlm-aud | DNSIX Network Level Module Audit | — | — | — | Assigned | → |
| 196 | TCP | dn6-smm-red | DNSIX Session Mgt Module Audit Redir | Lawrence Lebahn | — | — | Assigned | → |
| 196 | UDP | dn6-smm-red | DNSIX Session Mgt Module Audit Redir | Lawrence Lebahn | — | — | Assigned | → |
| 197 | TCP | dls | Directory Location Service | — | — | — | Assigned | → |
| 197 | UDP | dls | Directory Location Service | — | — | — | Assigned | → |
| 198 | TCP | dls-mon | Directory Location Service Monitor | Scott Bellew | — | — | Assigned | → |
| 198 | UDP | dls-mon | Directory Location Service Monitor | Scott Bellew | — | — | Assigned | → |
| 199 | TCP | smux | SMUX | Marshall Rose | — | — | Assigned | → |
| 199 | UDP | smux | SMUX | Marshall Rose | — | — | Assigned | → |
| 200 | TCP | src | IBM System Resource Controller | Gerald McBrearty | — | — | Assigned | → |
| 200 | UDP | src | IBM System Resource Controller | Gerald McBrearty | — | — | Assigned | → |
| 201 | TCP | at-rtmp | AppleTalk Routing Maintenance | — | — | — | Assigned | → |
| 201 | UDP | at-rtmp | AppleTalk Routing Maintenance | — | — | — | Assigned | → |
| 202 | TCP | at-nbp | AppleTalk Name Binding | — | — | — | Assigned | → |
| 202 | UDP | at-nbp | AppleTalk Name Binding | — | — | — | Assigned | → |
| 203 | TCP | at-3 | AppleTalk Unused | — | — | — | Assigned | → |
| 203 | UDP | at-3 | AppleTalk Unused | — | — | — | Assigned | → |
| 204 | TCP | at-echo | AppleTalk Echo | — | — | — | Assigned | → |
| 204 | UDP | at-echo | AppleTalk Echo | — | — | — | Assigned | → |
| 205 | TCP | at-5 | AppleTalk Unused | — | — | — | Assigned | → |
| 205 | UDP | at-5 | AppleTalk Unused | — | — | — | Assigned | → |
| 206 | TCP | at-zis | AppleTalk Zone Information | — | — | — | Assigned | → |
| 206 | UDP | at-zis | AppleTalk Zone Information | — | — | — | Assigned | → |
| 207 | TCP | at-7 | AppleTalk Unused | — | — | — | Assigned | → |
| 207 | UDP | at-7 | AppleTalk Unused | — | — | — | Assigned | → |
| 208 | TCP | at-8 | AppleTalk Unused | Rob Chandhok | — | — | Assigned | → |
| 208 | UDP | at-8 | AppleTalk Unused | Rob Chandhok | — | — | Assigned | → |
| 209 | TCP | qmtp | The Quick Mail Transfer Protocol | D. J. Bernstein | — | — | Assigned | → |
| 209 | UDP | qmtp | The Quick Mail Transfer Protocol | D. J. Bernstein | — | — | Assigned | → |
| 210 | TCP | z39-50 | ANSI Z39.50 IANA assigned this well-formed service name as a replacement for "z39.50". | Mark H. Needleman | — | — | Assigned | → |
| 210 | TCP | z39.50 | ANSI Z39.50 | Mark H. Needleman | — | — | Assigned | → |
| 210 | UDP | z39-50 | ANSI Z39.50 IANA assigned this well-formed service name as a replacement for "z39.50". | Mark H. Needleman | — | — | Assigned | → |
| 210 | UDP | z39.50 | ANSI Z39.50 | Mark H. Needleman | — | — | Assigned | → |
| 211 | TCP | 914c-g | Texas Instruments 914C/G Terminal IANA assigned this well-formed service name as a replacement for "914c/g". | Bill Harrell | — | — | Assigned | → |
| 211 | TCP | 914c/g | Texas Instruments 914C/G Terminal | Bill Harrell | — | — | Assigned | → |
| 211 | UDP | 914c-g | Texas Instruments 914C/G Terminal IANA assigned this well-formed service name as a replacement for "914c/g". | Bill Harrell | — | — | Assigned | → |
| 211 | UDP | 914c/g | Texas Instruments 914C/G Terminal | Bill Harrell | — | — | Assigned | → |
| 212 | TCP | anet | ATEXSSTR | Jim Taylor | — | — | Assigned | → |
| 212 | UDP | anet | ATEXSSTR | Jim Taylor | — | — | Assigned | → |
| 213 | TCP | ipx | IPX | Don Provan | — | — | Assigned | → |
| 213 | UDP | ipx | IPX | Don Provan | — | — | Assigned | → |
Look up a port number, service name, transport protocol, assignee or RFC in IANA's current registry. The table keeps every row in the 17 August 2026 snapshot, so one port can appear more than once when it has separate TCP, UDP or other registrations.
How to use the port lookup
Enter a number such as 22, 53, 80, 443, 3306 or 8080 to find exact registrations and any registered range containing that port. You can also search for a service such as ssh or mysql, a protocol, an assignee, or reference text such as RFC9110. Use the Protocol and Status filters when a search returns several rows.
Blank values mean the source registry does not provide that field. They have not been guessed. Assignee identifiers are resolved against the people and organisations directory in IANA's XML registry where a readable name is available.
Port ranges and status labels
- System ports: 0–1023. These are also commonly called well-known ports.
- User ports: 1024–49151. IANA can register services in this range.
- Dynamic or private ports: 49152–65535. IANA does not assign services from this range.
Status is a page-level label derived from the source row. Reserved and Unassigned follow IANA's description. Rows whose source text identifies a de-registration or removal are labelled Deprecated or removed. A row with a service name but no port is labelled Service name only. All other rows are labelled Assigned.
Why the same port can have several entries
TCP and UDP are different transport protocols, so the same number can be registered for both without representing the same network conversation. The registry also includes SCTP, DCCP, aliases, historic records and registrations without a specified transport protocol. They remain in this database so the source is not reduced to a hand-picked list.
Common port questions
What service normally uses port 22?
IANA registers ssh on port 22 for TCP and UDP, with an additional SCTP registration. In everyday networks, TCP port 22 is the familiar SSH remote-access service.
Why does port 53 show TCP and UDP?
The domain service is registered on port 53 for both TCP and UDP. DNS software chooses the transport according to the operation and response requirements.
What is the difference between ports 80 and 443?
IANA associates port 80 with HTTP-related service names and port 443 with HTTPS. A registration describes the conventional use; it does not inspect or guarantee the traffic running there.
What uses port 3306?
The registry lists mysql on port 3306 for TCP and UDP. MySQL client connections are ordinarily associated with TCP, but this page retains both official registry rows.
Is port 8080 always an HTTP proxy?
No. IANA registers http-alt on port 8080 for TCP and UDP, but applications can use ports differently. Identify the listening process and configuration before drawing a security conclusion.
Should I open a port because it is registered here?
No. Open only the ports required by a known application and restrict source networks where possible. A registry entry is not a firewall recommendation.
IANA updates the registry as assignments change. Use Report incorrect data if this snapshot no longer matches the official record, and include the IANA or RFC link so the change can be verified.
Provenance