Issue:
On an install of FreePBX 14 with responsive firewall and OpenVPN server enabled there is no mitigation against brute force attacks against the OpenVPN server. /var/log/messages is getting spammed with failed handshakes:

Feb 3 16:17:19 voipserver234 openvpn: Sun Feb 3 16:17:19 2019 103.37.x.x:49060 TLS: Initial packet from [AF_INET]103.37.x.x:49060, sid=6a22eb44 5adb63fe
Feb 3 16:17:19 voipserver234 openvpn: Sun……