@kerryfung - Not advisable to to use the ML /usr/sbin/racoon
I agree with JoshuaOchs - It worked for me initially however racoon failed startup following a reboot, even if I manually started as root ...
I've now gone back to the original Mavericks /usr/sbin/racoon and am back in the same boat - L2TP not working!
I've applied the update, which disappointingly does not mention any fix for L2TP! And not supprisingly L2Tp still does not work as intended!
As an aside, I have noticed if I am outside of my home network, connect to the 3rd party VPN service I subscribe to (which is also L2TP.) I can then connect to the L2TP VPN on my machine running Mavericks Server 3 ..
I'll say it again - WHY THE **** ARE YOU LEAVING US OUT IN THE COLD CRAPPLE? - NEARLY A MONTH NOW AND STILL NO FIX - VERY, VERY, VERY DISAPPOINTING ..