Say I have a public server with a service (email, web server, etc) that’s accessible through https://myservice.example.com, and I would like to restrict that service with a VPN. How do I do that?
I know how to setup a VPN. I know how to use some of the services through that VPN. But see, if I want to use that VPN, I connect my client to that VPN, then I get the subnet of that VPN, say 10.10.100.0, through which I can access the devices by address.
But I see some services offer things like https://myservice.example.com, and they only work when that VPN is connected. How does that work? Is it just some DNS setting at the domain level or there’s more to it?
Just… stop making it accessible from the Internet? Whatever you did to allow it through your firewall, just remove that rule.
Probably they have the service configured to only listen into the interface of the VPN.
Okay, the others are a little short for what you need.
Your VPN needs it’s own DNS. With that DNS you can route the traffic internally from the VPN subnet to the server. Then you can set the server up to only take requests from that subnet either via firewall or the reverse proxy.
100%.Or set host file entries on each endpoint to resolve the mail.domain.com to your internal ip that’s available only over vpn. Not going to be easy on mobiles.
There is an assumption though that the mail server has an internal IP address wherever you are hosting. That might not be true. I would always put the public IP on the firewall and then NAT with specific port 25 in to the private IP of the server, but who knows what this particular OP has done.
I think what you’re looking for is a firewall. Learn about ufw here.
Or, to simply answer your question,
sudo ufw allow from 10.10.100.0/24 sudo ufw enableOr just use internal ip addr for service.
Set myservice.example.com to an internal address like 10.10.100.x. Those addresses are not routable on the public internet. They can only be reached from a local network which the VPN tunnels you into.
If your VPN also supplies DNS to clients, can also add a private zone if its supported so nobody can resolve that internal address except those clients.
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I’ve seen in this thread:
Fewer Letters More Letters DNS Domain Name Service/System HTTP Hypertext Transfer Protocol, the Web IP Internet Protocol NAT Network Address Translation SSL Secure Sockets Layer, for transparent encryption TLS Transport Layer Security, supersedes SSL VPN Virtual Private Network VPS Virtual Private Server (opposed to shared hosting) nginx Popular HTTP server
8 acronyms in this thread; the most compressed thread commented on today has 19 acronyms.
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