This a purely a paper work exercise and has no practical use for me, but how would one allow the L2TP over IPsec VPN built into the Draytek 2860 router to work directly from within the local network.

In essence my L2TP over IPsec VPn works nicely when I am out and about with the 4G on my iPhone or when I have my laptop at my Grandparents, however when I am home I can not connect to my own VPN.

Is NAT lookback preventing it from working at home?

Essentially I want to know how one would get it to work where the WAN IP of the VPN client is the same as the WAN IP of the VPN server.

Regards: Elliott.

I doubt you can as the VPN endpoint is on the WAN interface. Loopback isn't for VPN.

I don't know why this doesn't work, but I have noted the problem on the 2860n.

I say "problem", because it does work on a 2830n in the same scenario...(though on the 2830n, it's easier to demonstrate using SSL and the Smart VPN app, since it seems not overly fond of the built-in Android L2TP vpn client.)