Connection timed out for netcat after opening port in router

Question

So, my situation is that I have one Windows PC and one PC with Kali Linux. On Windows PC I've opened a netcat listener on port 4444. Then on my router I've opened port 4444.

Finally when I go on kali and, using my mobile data hotspot, I want to connect to my Windows. But when I try it doesn't work, and when I check ports using:

nc -vn HOSTNAME PORT

it says:

Connection timed out.

Could anyone help me please? I've already tried using netcat between the two PCs in the same network and it works perfectly, so I thinks it's a network problem. My router is an Asus DSL-N12E_C1.

Answer 1

On Windows PC I've opened a netcat listener on port 4444.

Make sure your netcat binds and listens on all IP addresses, not only on localhost, e.g.

nc -v -l 0.0.0.0 4444

See: Netcat for Windows.

Then make sure you can connect to that port on the same machine. Then try remotely.

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Then on my router I've opened port 4444.

Apart of opening the port, make sure that you've also forwarding that port into the right host like:

• PUBLIC_ROUTER_IP:4444 <-> INTERNAL_WINDOWS_IP:4444

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To connect to the remote port, run:

nc -v example.com 80

or use telnet command, e.g.

telnet PUBLICIP PORT

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See also: Why is "nc -l xxxx" not opening a port?