Ports by service
The port reference on this site is keyed by number, which is the wrong way round for the question people usually have: you know the service and you want the port. This is the same data, keyed by name.
Several of them have more than one answer. SMTP uses 25 between servers, 587 for a mail client submitting a message, and 465 for implicit TLS — a single number is wrong for two of those three jobs.
- SMTP — 25, 465, 587
- IMAP — 143, 993
- POP3 — 110, 995
- LDAP — 389, 636
- HTTP — 80, 8000, 8080
- HTTPS — 443, 8443
- FTP — 20, 21
- DHCP — 67, 68
- Docker — 2375, 2376
- MQTT — 1883, 8883
- SSH — 22
- RDP — 3389
- MySQL — 3306
- PostgreSQL — 5432
- SQL Server — 1433
- Oracle — 1521
- MongoDB — 27017
- Redis — 6379
- Memcached — 11211
- Elasticsearch — 9200
- DNS — 53
- NTP — 123
- SMB — 445
- NFS — 2049
- SNMP — 161
- Syslog — 514
- RabbitMQ — 5672
- Prometheus — 9090