Only local connections work for me.

[X7895]

Local connections using this works fine:

server1 = new SimpleTcpServer("127.0.0.1:9000");

Client1 = new SimpleTcpClient("127.0.0.1:9000");

External connections using this code don't work:

IP of the PC that hosts the server: 67.231.135.128

server1 = new SimpleTcpServer("0.0.0.0:9000");

Client1 = new SimpleTcpClient("67.231.135.128:9000");

Is this code correct?
Windows Firewalls are disabled.
What else could be blocking the connection?

[jchristn]

Hi, are you running your server as administrator?

[X7895]

Just 2 normal PCs with Windows 10. One starts the serverprogram the other one the client program.

[jchristn]

Are they both on the same network? You're attempting to connect to a 67.x address but I'm guessing that's your public IP, and the machines are on the same private network. Is that the case?

[X7895]

No they are not on the same private network.
Its 2 PCs in different Networks that have to connect over the internet.
They both have different public IPs.
The 67.231.135.128 adress was just an example for a public IP.
I of course use my real public IP adress for the server.

[jchristn]

Is that IP actually assigned to the machine or is it assigned to a NAT router? Can you send me the output of ipconfig? Also are these laptops/PCs that you have physically, or are they virtual machines? And if virtual machines, are they on a machine you control or a cloud instance?

[X7895]

Its 2 physical PCs in 2 different houses.
The IP is the public IP of the NAT router the PC that hosts the server is behind.

Ipconfig:
Verbindungsspezifisches DNS-Suffix: home
IPv6-Adresse. . . . . . . . . . . : 2a02:908:950:e6e0:def9:ba3a:f31c:e3ce
Temporäre IPv6-Adresse. . . . . . : 2a02:908:950:e6e0:b123:c3e6:a3db:19dd
Verbindungslokale IPv6-Adresse . : fe80::130b:4dc2:47ee:fe97%2
IPv4-Adresse . . . . . . . . . . : 192.168.0.122
Subnetzmaske . . . . . . . . . . : 255.255.255.0
Standardgateway . . . . . . . . . : fe80::925c:44ff:fecf:921b%5
192.168.0.1

[jchristn]

Ok. Your listener then has to be on 0.0.0.0 and your router must be set up to port-forward inbound requests on port 9000 to 192.168.0.122.