Port-Checker

So verwenden Sie dieses Tool

1. 1

   Type the public hostname or IP you want to probe (for example example.com) into the host field.

2. 2

   Set the port number, either by typing it or clicking one of the quick presets like 22, 80, 443, or 3306.

3. 3

   Click Check and wait up to five seconds for the result.

4. 4

   Read the result banner: green means the port accepted a TCP connection (with latency in milliseconds), red means it did not (with the reason code).

Was ist der Port-Checker?

Häufige Anwendungsfälle

• Confirm a freshly deployed web app is reachable on port 443 before pointing DNS or a load balancer at it.

• Diagnose why clients cannot connect to a database by checking whether 3306 or 5432 is actually exposed.

• Verify a new firewall or security-group rule opened (or closed) the port you intended.

• Check that a sensitive service like Redis on 6379 or MongoDB on 27017 is NOT left open to the public internet.

• Test whether an outbound SSH or SMTP port is blocked between a remote host and the public internet.

• Validate that a port-forward or reverse proxy is passing traffic through to the expected backend port.

Häufig gestellte Fragen