Live connection diagnosis

RDP Port Checker

Verify TCP reachability without confusing an open socket with a successful or secure RDP login.

RDP reachability diagnosis

Test the public TCP endpoint only if you intentionally expose RDP. Prefer a VPN or overlay for normal remote administration.

Measured evidence first

Detected public IPChecking…

IP version—

Network—

The public IP shown here is detected from this browser request. External probes are restricted to that same public IP.

Security note: exposing RDP directly to the public internet increases attack surface. A VPN/overlay such as a private mesh is generally safer than publishing TCP 3389.

What the probe can tell you

A reachable result confirms the selected public TCP port accepts a connection. It does not verify Windows credentials, Network Level Authentication or the full RDP session.

Use the configured RDP listening port

Microsoft documents TCP 3389 as the default Remote Desktop listening port. If the Windows host has been configured to use another port, test that configured port instead and make sure the matching firewall rule was updated.

A reachable TCP socket does not validate credentials, Network Level Authentication or the complete desktop session. For routine internet access, an authenticated VPN or overlay avoids exposing the RDP listener directly.

RDP over Tailscale guidance · CGNAT test · Why is my port closed?

Official reference: Microsoft Learn.