AZ Tools

Port Number Reference

Network

Quick lookup for the ports you actually meet in firewall rules, docker-compose files, and tcpdump output — well-known (< 1024), registered (1024–49151), and the conventional dev / database ports. Each entry lists the protocol (TCP / UDP / both), the service name, and a one-line description.

PortProtoServiceDescription
20tcpFTP-DATAFile Transfer Protocol — data channel.
21tcpFTPFile Transfer Protocol — control channel.
22tcpSSHSecure Shell. Also used by SFTP and SCP.
23tcpTelnetPlaintext remote shell. Avoid on the open internet.
25tcpSMTPSimple Mail Transfer Protocol — server-to-server mail.
53bothDNSDomain Name System lookups. UDP for queries, TCP for zone transfers and large answers.
67udpDHCP serverDynamic Host Configuration Protocol — server-side.
68udpDHCP clientDHCP — client-side.
69udpTFTPTrivial File Transfer Protocol — bootstrapping / firmware.
80tcpHTTPPlain HTTP. Browsers default to this when the URL has no scheme.
110tcpPOP3Post Office Protocol 3 — legacy mail retrieval.
119tcpNNTPNetwork News Transfer Protocol — Usenet.
123udpNTPNetwork Time Protocol.
143tcpIMAPInternet Message Access Protocol — mailbox sync.
161udpSNMPSimple Network Management Protocol — device monitoring.
162udpSNMP trapSNMP asynchronous notifications.
389tcpLDAPLightweight Directory Access Protocol.
443tcpHTTPSHTTP over TLS. Default for the modern web.
445tcpSMBServer Message Block — Windows file sharing.
465tcpSMTPSSMTP over TLS (implicit). Common for mail submission.
514udpsyslogUnix syslog forwarding.
587tcpSMTP submissionMail submission from clients with STARTTLS.
631tcpIPP / CUPSInternet Printing Protocol; macOS / Linux print server.
636tcpLDAPSLDAP over TLS.
989tcpFTPS-dataFTPS data channel (implicit TLS).
990tcpFTPSFTPS control channel (implicit TLS).
993tcpIMAPSIMAP over TLS.
995tcpPOP3SPOP3 over TLS.
1080tcpSOCKSSOCKS proxy.
1194udpOpenVPNOpenVPN default port.
1433tcpMSSQLMicrosoft SQL Server.
1521tcpOracleOracle Database default listener.
1701udpL2TPLayer 2 Tunneling Protocol — VPN.
1723tcpPPTPPoint-to-Point Tunneling Protocol — legacy VPN.
1883tcpMQTTMessage Queuing Telemetry Transport — IoT messaging.
2049tcpNFSNetwork File System.
2375tcpDocker (plain)Docker daemon socket — unencrypted, dev only.
2376tcpDocker (TLS)Docker daemon socket — TLS.
3000tcpdev serverConventional Node.js dev port — Next.js, Express, …
3306tcpMySQLMySQL / MariaDB.
3389tcpRDPMicrosoft Remote Desktop Protocol.
3478bothSTUN / TURNWebRTC NAT-traversal — STUN / TURN servers.
4444tcpSeleniumSelenium WebDriver default hub.
5000tcpFlask / UPnPPython Flask dev default; UPnP on macOS.
5060bothSIPSession Initiation Protocol — VoIP signalling (plain).
5061tcpSIP-TLSSIP over TLS.
5432tcpPostgreSQLPostgreSQL default listener.
5900tcpVNCVirtual Network Computing.
6379tcpRedisRedis default port.
6443tcpKubernetes APIKubernetes API server (HTTPS).
6667tcpIRCInternet Relay Chat.
8000tcpdev serverCommon alt HTTP — Python `http.server`, Django.
8080tcpHTTP-altAlternative HTTP — Tomcat, Jenkins, proxies.
8443tcpHTTPS-altAlternative HTTPS — admin panels, alt webservers.
8888tcpHTTP-alt / JupyterAlternative HTTP; Jupyter Notebook default.
9000tcpPHP-FPMPHP FastCGI Process Manager.
9090tcpPrometheusPrometheus metrics scraper.
9092tcpKafkaApache Kafka broker.
9200tcpElasticsearchElasticsearch REST API.
11211tcpmemcachedmemcached default port.
27017tcpMongoDBMongoDB default port.

How to use

  1. Type a port number (`443`), a service name (`postgres`), or a keyword (`mail`).
  2. Filter to well-known / registered / ephemeral ranges if you want to narrow down.
  3. Click copy to grab the port number for a docker-compose port mapping or firewall rule.

Frequently asked questions

What do `well-known`, `registered`, and `ephemeral` mean?
IANA divides the 16-bit port space into three ranges: well-known (0–1023, system ports for standardized services), registered (1024–49151, applications and vendor-assigned), and ephemeral (49152–65535, dynamic / private ports for outgoing connections). On Unix you need root to bind below 1024.
Why are some ports listed as `both`?
DNS, SIP, and STUN, for example, are defined for both TCP and UDP. The `both` marker tells you the port is registered on both protocols, not that the same service must use them simultaneously.
Are these the actual reserved ports?
Yes — they're either IANA assignments (22, 80, 443, 53, …) or de-facto defaults from the upstream project (3306 MySQL, 6379 Redis, 27017 MongoDB). Implementations can listen on a different port, of course.

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