Port 1433: SQL Server
Common Ports Reference: What runs on port 3389, 445 or 5985: common TCP and UDP ports for web, mail, Windows, AD, databases and VPNs, with security notes.
The ports that come up when opening a firewall, reading a scan or troubleshooting a connection: what runs on each, TCP or UDP, and what to watch out for. Search by number or name. Port numbers and service names were checked against IANA's port number registry; ports that are widely used but assigned by IANA to something else are marked unofficial.
1 of 96 ports
What a domain controller and Windows servers listen on.
| Port | Protocol | Service | What it's for | IANA name |
|---|---|---|---|---|
| 1433 | TCP | SQL Server | The default instance. Named instances use dynamic ports, found through 1434. | ms-sql-s |
Careful: Never open this to the internet; reach it over a VPN or from trusted networks only. | ||||