Fixed: No VPN connectivity with Asus RT-N56U with firmware 1.0.1.8b

After upgrading to the latest firmware on my Asus RT-N56U router, I was unable to connect to my work VPN through the wireless or wired connections at home.  I tried all possible wireless encryption combinations, disabled encryption, dmz'd my laptop's ip, but none of that work.  I was able to connect to the VPN on other networks, so I knew it was my router or my ISP.  I called my ISP to see if they were blocking any ports - they do not.  The helpful tech support fellow pointed me to the PPTP Passthrough setting, which had been moved around on the router's GUI with the new firmware.  This is where I found it:

It was enabled as it should've been.  It turns out that I had to enable the IPSec Passthrough setting.