Create Guest WIFI on MSM760

Hi there,

I am having trouble setting up my guest WIFI on my MSM760.

I have set up a guest SSID that uses HTML based logins.  This works totally fine, however all traffic on my proxy shows as the MSM760's internet port IP address.  I would like this so i can see the IP address that is associated with the device.  So we can track web filtering on our proxy.

Current setup:

Interfaces: Internet port IP: 10.10.1.15 mask 255.255.0.0

LAN port IP: 10.140.1.1 mask 255.255.0.0

Guest VLAN: 140

DHCP server config (on the MSM) 
IP:  10.140.0.1 - 10.140.11.184

GW 10.140.1.1.

I believe this is a problem on the NAT on the interner interface, but i cant seem to get internet once i untick this.  Any help would be great!

Thanks.