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ipaddress.tr

Port-Checker

Wir öffnen von unserem Server eine einzige TCP-Verbindung zum gewählten Port der Adresse, von der Sie diese Seite aufrufen – nie zu einer anderen Adresse.

Ihre öffentliche Adresse: 216.73.217.58

Damit daraus kein Scan-Dienst wird, prüft das Tool ausschließlich die Adresse, von der Ihre Anfrage kommt. Um ein anderes Netz zu prüfen, öffnen Sie diese Seite aus jenem Netz.

Häufige Ports

Auf diese Weise lässt sich nur TCP prüfen. UDP-Dienste (WireGuard, viele Spiele) antworten nicht auf eine unaufgeforderte Anfrage, daher ist ein offener UDP-Port nicht von einem geschlossenen zu unterscheiden.

Dieser Text ist noch nicht auf Deutsch verfügbar. Er wird auf Englisch angezeigt, bis eine Übersetzung erscheint.

A port is the number that tells a device which program a connection is for: 443 for a web server, 22 for SSH, 25565 for a Minecraft server. When you run something at home that others should reach — a game server, a security camera, a NAS, a remote desktop — your router has to forward the port from its public address to the device inside your network.

This tool answers one question: is that port reachable from the internet right now? Our server opens a single TCP connection to the port you choose on the address your request comes from and reports what happens:

  • Open — something completed the TCP handshake. The service is reachable.
  • Closed — your connection answered with a refusal (RST): the router or the device is there, but nothing listens on that port, or the forward points to the wrong device.
  • No answer (filtered) — nothing came back within three seconds. A firewall drops the packets, the router does not forward the port, or you are behind carrier-grade NAT (CGNAT): many customers share one public IPv4 address, so incoming connections cannot be forwarded to you at all. Mobile connections are almost always behind CGNAT, and some fixed-line providers use it too.

The tool never tests another address: a port checker that accepts any target is a scanner for other people’s networks. Only TCP can be tested; UDP services do not answer an unsolicited probe.

Häufig gestellte Fragen

My port shows as filtered although I forwarded it. Why?

Check three things: the router's WAN address must be the same as the address shown here (otherwise you are behind CGNAT), the forward must point to the device's current local address, and the device's own firewall must allow the port. Some providers also block common server ports such as 25 and 80 on home lines.

How do I know whether I am behind CGNAT?

Open your router's status page. If its internet (WAN) address differs from your public address here, or starts with 100.64–100.127, you share a public address with others. Ask your provider for a public IPv4 address (often a paid static IP) or use IPv6, where every device can be reachable.

Is an open port dangerous?

Only if what listens on it is outdated or badly protected. Expose only what you need, keep it updated, use strong passwords or keys, and close forwards you no longer use.

Can I test my server's ports from here?

Only from the server's own connection: the tool tests the address the page is loaded from. To test a remote server, open this page on that network, or use a tool you run yourself.

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