§ 01 / TOOL

Port Lookup.

STATUS READYENTRIES 81SOURCE IANA + COMMON DEV

> SEARCH

BY PORT NUMBER OR SERVICE NAME

PORTS.

81 OF 81

20
FTP-DATA
File Transfer Protocol — data channel.
TCP
21
FTP
File Transfer Protocol — control channel.
TCP
22
SSH
Secure Shell — encrypted remote login.
TCP
23
Telnet
Plaintext remote login (deprecated; use SSH).
TCP
25
SMTP
Simple Mail Transfer Protocol — sending mail.
TCP
53
DNS
Domain Name System.
TCP/UDP
67
DHCP (server)
Dynamic Host Configuration Protocol — server.
UDP
68
DHCP (client)
DHCP — client.
UDP
69
TFTP
Trivial File Transfer Protocol.
UDP
80
HTTP
World Wide Web — unencrypted.
TCP
110
POP3
Post Office Protocol v3 — mail retrieval.
TCP
119
NNTP
Network News Transfer Protocol.
TCP
123
NTP
Network Time Protocol — clock sync.
UDP
135
MS RPC
Microsoft RPC endpoint mapper.
TCP
137
NetBIOS-NS
NetBIOS Name Service.
UDP
138
NetBIOS-DGM
NetBIOS Datagram Service.
UDP
139
NetBIOS-SSN
NetBIOS Session Service / SMB over NetBIOS.
TCP
143
IMAP
Internet Message Access Protocol.
TCP
161
SNMP
Simple Network Management Protocol.
UDP
162
SNMP Trap
SNMP — traps from agents to managers.
UDP
179
BGP
Border Gateway Protocol — internet routing.
TCP
194
IRC
Internet Relay Chat.
TCP
220
IMAP3
IMAP version 3.
TCP
389
LDAP
Lightweight Directory Access Protocol.
TCP
443
HTTPS
HTTP over TLS — encrypted web.
TCP
445
SMB
Server Message Block — file sharing.
TCP
465
SMTPS
SMTP over implicit TLS (legacy).
TCP
514
syslog
System log forwarding.
UDP
515
LPD
Line Printer Daemon.
TCP
587
SMTP (submission)
Mail submission with STARTTLS.
TCP
631
IPP / CUPS
Internet Printing Protocol.
TCP
636
LDAPS
LDAP over SSL.
TCP
853
DNS over TLS
Encrypted DNS (DoT).
TCP
873
rsync
rsync file transfer daemon.
TCP
989
FTPS-DATA
FTP over TLS — data.
TCP
990
FTPS
FTP over TLS — control.
TCP
993
IMAPS
IMAP over TLS.
TCP
995
POP3S
POP3 over TLS.
TCP
1080
SOCKS
SOCKS proxy.
TCP
1194
OpenVPN
OpenVPN default port.
UDP
1433
MSSQL
Microsoft SQL Server.
TCP
1521
Oracle
Oracle DB listener.
TCP
1701
L2TP
Layer 2 Tunneling Protocol.
UDP
1723
PPTP
Point-to-Point Tunneling Protocol.
TCP
1812
RADIUS auth
RADIUS authentication.
UDP
1813
RADIUS acct
RADIUS accounting.
UDP
2049
NFS
Network File System.
TCP/UDP
2375
Docker
Docker daemon (unencrypted — disable in prod).
TCP
2376
Docker TLS
Docker daemon over TLS.
TCP
3000
Common dev
Node/Next.js/Rails dev servers.
TCP
3001
Common dev
Frequent secondary dev port.
TCP
3306
MySQL
MySQL / MariaDB.
TCP
3389
RDP
Microsoft Remote Desktop Protocol.
TCP
3478
STUN/TURN
WebRTC NAT traversal.
TCP/UDP
4433
HTTPS-alt
Common alternate HTTPS dev port.
TCP
5060
SIP
Session Initiation Protocol — VoIP signaling.
TCP/UDP
5061
SIPS
SIP over TLS.
TCP
5222
XMPP
Jabber / XMPP client connections.
TCP
5353
mDNS
Multicast DNS / Bonjour / Avahi.
UDP
5432
PostgreSQL
PostgreSQL database.
TCP
5601
Kibana
Kibana dashboard.
TCP
5672
AMQP
Advanced Message Queueing Protocol — RabbitMQ.
TCP
5900
VNC
Virtual Network Computing.
TCP
5984
CouchDB
CouchDB HTTP API.
TCP
6379
Redis
Redis in-memory data store.
TCP
6443
Kubernetes API
Kubernetes API server.
TCP
6667
IRC
IRC server (alternate).
TCP
7000
Common dev
Cassandra inter-node / common dev.
TCP
8000
HTTP-alt
Common HTTP dev / Django default.
TCP
8080
HTTP-alt
Common alternate HTTP — proxies, dev servers.
TCP
8086
InfluxDB
InfluxDB HTTP API.
TCP
8443
HTTPS-alt
Common alternate HTTPS.
TCP
8888
HTTP-alt
Common alternate HTTP / Jupyter default.
TCP
9000
Common dev
PHP-FPM, SonarQube, etc.
TCP
9090
Prometheus
Prometheus metrics server.
TCP
9092
Kafka
Apache Kafka broker.
TCP
9200
Elasticsearch
Elasticsearch HTTP API.
TCP
9418
git
git daemon (git://).
TCP
11211
Memcached
Memcached cache.
TCP
27017
MongoDB
MongoDB database.
TCP
50000
SAP
SAP NetWeaver dispatcher.
TCP

§ 02 / ABOUT

The port number space.

A TCP or UDP port is a 16-bit number (0–65535) that identifies an endpoint on a host. Combined with the IP address, it forms the “socket” — the unique pair that identifies a network conversation. IANA divides the space into three ranges.

// THE THREE RANGES

Well-known (0–1023) — Standard services. HTTP=80, HTTPS=443, SSH=22, etc. Binding requires root/admin on Linux/macOS.
Registered (1024–49151) — Vendors apply to IANA for assignments. PostgreSQL=5432, Redis=6379, etc.
Dynamic/Ephemeral (49152–65535) — Source ports for outbound client connections. Pool size means thousands of simultaneous connections per IP.

// SECURITY NOTE

Just because a port is "registered" to a service doesn’t mean traffic on that port IS that service. Tools can listen on any port. When auditing, verify the actual protocol with packet inspection or banner grabbing — not just the port number.

§ 03 / FAQ

Port questions.

What’s the difference between TCP and UDP?+

TCP is connection-oriented and reliable — it sets up a session, sequences and retransmits packets, and guarantees ordered delivery. UDP is fire-and-forget — fast, no setup, no delivery guarantees. Use TCP for HTTP, SSH, file transfer; UDP for DNS, NTP, VoIP, real-time gaming.

What does "well-known" vs "registered" port mean?+

IANA splits the port space into three: 0–1023 are "well-known" (assigned to standard services like HTTP, SSH); 1024–49151 are "registered" (vendors apply to IANA for an assignment); 49152–65535 are "dynamic/ephemeral" (used by client OS for outbound connection source ports). Most apps below 1024 require root to bind on Linux.

Why are some ports listed as both TCP and UDP?+

A few protocols use both. DNS (port 53) traditionally uses UDP for normal queries and TCP for zone transfers and large responses. NFS uses both depending on version. SIP, STUN, and a few others negotiate at runtime.

How do I check what’s listening on a port?+

On macOS/Linux: lsof -i :PORT. On Linux specifically: ss -tlnp (TCP listening) or ss -ulnp (UDP listening). On Windows: netstat -ano | findstr :PORT. nmap is the cross-platform option for scanning a remote host.

§ 04 / TOOLS

Related calculators.

§ 05 / READING