The National Security Agency released its Securing IPsec Virtual Private Networks document. The document discusses the regular tasks you should do to keep your network secure. Use the current version of your VPN software to lock down your connections. Use vendor-provided updates (patches) for VPN gateways and clients to make sure they are updated. Use default VPN settings to reduce the attack surface of the VPN gateway and reduce the risk of an attack by reducing the risk to your network. Use vendor updates to update your VPN clients and clients with security updates.”]
Source: https://www.csoonline.com/article/3567052/optimizing-vpns-for-security-5-key-tasks.html