I have a VPS running an HTTPS admin service on TCP 5678.
I want to restrict this to OpenVPN users only and have tried the following:
iptables -A INPUT -s 10.8.1.0/24 -p tcp -m tcp --dport 5678 -m conntrack --ctstate NEW -j ACCEPT
Unfortunately this service is still open to the internet. How do i lock it down so only OpenVPN users can access it?
Operating system is Debian.
iptables -S -P INPUT ACCEPT -P FORWARD ACCEPT -P OUTPUT ACCEPT