Xjyuk

I have a domain (e.g. example.com), static IP (e.g. 212.5.5.5) and local devices at 192.168.0.1:80, 192.168.0.2:80, 192.168.0.3:80, 192.168.0.4:80, 192.168.0.4:47 (this one is not a website).

How do I access these devices using subdomains (ex. device1.example.com, device2.example.com , etc.)?

Currently I was only able to get example.com:80 and example.com:47 working, which point to 192.168.0.4:80, 192.168.0.4:47.

I know that you cannot set the port on DNS server.

How I should overcome my problem?

You can have one public facing server running nginx reverse proxy that redirects traffic based on subdomain to the correct server.

nginx configuration on your "main" server:

server 
 server_name device1.example.com;
 location / 
 proxy_pass http://192.168.0.1:80;
 

server 
 server_name device2.example.com;
 location / 
 proxy_pass http://192.168.0.2:80;
 

server 
 server_name device3.example.com;
 location / 
 proxy_pass http://192.168.0.3:80;
 

If you have only one external IP address, then:

The first thing is to differentiate my port, you seem to have done this.

Next for all the port 80s, you can use nginx as a reverse proxy to route traffic to the various places. You can tell it exactly what you asked for e.g. route http://device1.example.com to 192.0.0.1:80 etc. An alternative is to route http://example.com/device1 to 192.0.0.1:80.

To do the first way see virtual hosts, in the nginx manual.

You will also have to point all of the names to the external IP address, if using the virtual host method. Or just the base domain, if using the directory method.

You'll need to use alternate ports for everything except one of them. For example, 212.5.5.5:80 would forward to 192.168.0.1:80, but then 212.5.5.5:81 would forward to 192.168.0.2:80, and 212.5.5.5:82 would forward to 192.168.0.3:80, and so on. This should be configurable on most modern NAT devices.

Another way, if you're willing to use IPv6, is just turn on IPv6 pass-through on your NAT device or router. That basically exposes every IPv6 address on your LAN to the public internet, letting you access them directly from the outside. As you might imagine, there is some risk associated with this. It's up to you to decide if that risk is tolerable.

If your DNS server is running on your network, you could configure your DNS server and add records for each subdomain to point to an internal IP.

If this is not the case, then you can use a router to forward ports like so:

212.5.5.5:444 forward to 192.168.0.2:80

and

212.5.5.5:333 forward to 192.168.0.3:80

Then to access 192.168.0.2:80 from outside you connect to 212.5.5.5:444 or domain.com:444

and to access 192.168.0.3:80 from outside you connect to 212.5.5.5:333 or domain.com:333

and so on...