Port 1433 — Microsoft SQL Server

Security guidance

A database should never accept connections from the internet. Bind to localhost or a private network and reach it over a VPN.

Test port 1433 yourself

From your own machine, against any host (swap in your domain):

macOS / Linux — netcat

nc -vz example.com 1433

Any OS — nmap

nmap -p 1433 example.com

Windows — PowerShell

Test-NetConnection example.com -Port 1433

open = a service answered on port 1433; closed = the host replied but nothing is listening; filtered = a firewall silently dropped the probe. These test from your network — our port checker tests from the outside, the view that matters for security.

Other common ports