How do I check if port 1433 is open?

Enter your public IP or hostname into the scanner tool and click Check. A sub-second raw TCP socket handshake will be initiated from our edge server to port 1433 on your target. If the 3-way handshake finishes with SYN-ACK, the port is OPEN. If an RST packet is returned, the host is reachable but the port is CLOSED. If packets time out without response, the port is FILTERED by an ISP or firewall.

Is port 1433 safe to expose to the public internet?

Exposing port 1433 carries elevated security risks (High risk). Targets automated brute-force attacks against the 'sa' (system administrator) account. Keep behind firewall or VPN. For remote services, consider placing them behind a secure VPN (such as WireGuard or Tailscale) or restricting inbound access with strict IP firewall rules.

Why does port 1433 show as closed or filtered?

If port 1433 reports CLOSED or FILTERED, confirm that: 1) Your service is actively running and bound to 0.0.0.0 (not just localhost/127.0.0.1); 2) Your router has a port forwarding rule directing external port 1433 to your machine's local IP; 3) Your operating system firewall (Windows Defender Firewall, ufw, or iptables) allows incoming connections on port 1433.

PORT 1433 TCP Database High Risk

Port 1433 (Microsoft SQL Server) Open Check

Q: What is port 1433 used for?

Port 1433 is the standard TCP port used for Microsoft SQL Server. It is commonly used by Microsoft SQL Server, SQL Server Management Studio (SSMS), Azure SQL Edge. Default listener port for Microsoft SQL Server relational database engine.

Default listener port for Microsoft SQL Server relational database engine.

Live Socket Reachability Probe

Pre-configured for Port 1433

Port Scanner

Quick:

Recent Probes 0

Stored locally in browser • 0 logs on server

No recent scans recorded.

Target hosts and tested ports will appear here automatically for fast 1-click re-testing.

Auto-prunes oldest probes beyond 10 entries (FIFO)

Port Specifications & Network Behavior

Standard Port Number 1433

Primary Service Microsoft SQL Server

Transport Protocol TCP

Traffic Classification Database

Residential ISP Status Typically unrestricted by consumer ISPs

Security Exposure High Exposure discouraged without VPN or firewall protection

Security Advisory: Microsoft SQL Server (Port 1433)

Targets automated brute-force attacks against the 'sa' (system administrator) account. Keep behind firewall or VPN.

Recommendation: Keep port 1433 closed to WAN traffic. Connect remotely using WireGuard, Tailscale, or an SSH tunnel.

Port Forwarding & Troubleshooting Checklist

If port 1433 returns CLOSED or FILTERED, work through this verified diagnostic checklist:

1 In SQL Server Configuration Manager, ensure 'TCP/IP' protocol is enabled under Network Configuration.
2 Confirm IPAll TCP Port is explicitly set to 1433 in TCP/IP Properties.
3 Allow inbound TCP 1433 in Windows Defender Firewall on the database host.

Verify Host Is Listening Locally

Windows (PowerShell) netstat -ano | findstr :1433

Linux / macOS (Bash) ss -tulpn | grep :1433