I have a Routing and Remote Access Server behind my SSG and I would like to use it for L2TP VPN. When I try to forward UDP 500 using VIP on my interface, I get a message saying it's not supported, 500 is for management of the box.
I'm also currently using site-to-site VPN which I imagine is using port 500 on the same interface. Is this what is stopping me?
Would there be any way around this? My goal is to allow clients such as Windows PCs and iOS devices to connect to my network without using a certificate and instead a preshared key -- which RRAS supports.