各类VPN的安装方法

PPTP：

• https://effmx.com/articles/zai-vpsshang-da-jian-pptp-vpnde-ji-jian-gong-lue/
• https://github.com/teddysun/across/blob/master/pptp.sh
• https://github.com/DanylZhang/VPS/blob/master/CentOS-pptp-setup.sh

L2TP/IPSEC:

• https://github.com/hwdsl2/setup-ipsec-vpn
• https://raw.githubusercontent.com/hwdsl2/setup-ipsec-vpn/master/vpnsetup_centos.sh
• https://teddysun.com/448.html

openvpn:

• https://github.com/angristan/openvpn-install
• https://github.com/Nyr/openvpn-install

wiregrand:

• https://github.com/angristan/wireguard-install
• https://teddysun.com/554.html