L2TP IPSec on Linux Server

[cspears]

I have softether running on a CentOS7 Server. Using the client from a windows computer or SSTP from the native windows client works great...but I can’t for the life of me get L2TP to works. I have UDP ports 500 1701 and 4500 forwarded from the wan side of my router to the IP of the server. However, L2TP from an iOS or Windows client both return failed to communicate with the server. Am I missing a step somewhere on the server side? NMAP of the localhost show the three ports open but filtered.