I can get online connecting directly to my PC/Mac but not using a NAT Router in between. Why?
The DSL-300G is designed to "lock" on the machine it'sinstalled on.
If you wish to put a NAT Router in between (eg. DI-624) you willneed to make a few adjustements.
- Connect computer to routers' LAN port, or wirelessly
 - Connect routers' WAN port to DSL-300G
 - Change LAN IP of router, to eg. 192.168.1.1, save andreboot.
 - Reset the DSL-300G , using the button on the back. (Hold for10s)
 - On your computer, go to your web browser and type in theaddress http://192.168.0.1 press OK
 - Enter your ADSL account details, provided by your ISP, save andreboot.
 
For more detailed guide, please download this