L2TP VPN

Afternoon all,

Little L2TP issue I'm having and I'd like to see if you guys would have an idea on how to resolve it.

I setup an L2TP VPN on our WAN interface for users who still use windows clients to connect VPN to the office.

My users are able to connect from their phone or from their laptop providing they have an internet access for the last one.

However, when they want to tether off their phone to access the corporate network... tethering client fails... I've tried both ways :

1- Laptop tethers off phone to access internet, establishes VPN (that part works) but the traffic from the laptop doesn't reach Corporate network.

2- Phone establishes the VPN (that part works), laptop tethers off of it but is unable to reach corporate network. Now I've tried this with both android phone and iPhone... same results

What I am missing ?