https://www.digitalocean.com/community/tutorials/how-to-set-up-and-configure-an-openvpn-server-on-ubuntu-20-04

sudo apt update sudo apt install openvpn easy-rsa

./easyrsa init-pki

./easyrsa gen-req kr-1.esukmean.com nopass

./easyrsa sign-req server kr-1.esukmean.com

./easyrsa gen-req username

./easyrsa sign-req client client1

서버용 키 잘 만들고, 클라용 키 잘 만들것