How do I enable VPN passthrough for an internal VPN server ?
This applies to NAT mode only. If you have a VPN server running behind the Vigor router (as opposed to using the Vigor’s own VPN facilities) you can set the router to pass through to it. This will work for PPTP, L2TP IPSec+ESP protocols; it will not work for IPSec+AH mode because the AH protocol is designed to block address translation (due to embedding the source IP addresses in the header). You must firstly disable the router’s own VPN facility, otherwise it will intercept the VPN traffic : The PPTP protocol uses TCP Port 1723 for link setup, and IPSec/ESP uses Port500 for IKE setup. If you enable those ports in the router’s open port setup, the router will automatically also open up the corresponding VPN protocol, i.e. GRE or ESP respectively. The screenshot below shows this method for the IPSec or PPTP protocols: You do not need to set all of those rules above – select whichever of PPTP, IPSec or L2TP you are using (you can use all of them). If the above method does not work for yo
