NETGEAR WNR1000v3 - public IP instead of private IP

Hello

I moved to a new house and set up and internet service here. So I've had my own modem + router (WNR1000v3). The router itself works fine and providing internet.

However, when I tried to access routerlogin.net OR the IP address, the requests times out. Which means that I can not set up a password to protect my network.

I called the support and figured that my router is giving public IP address instead of private IP address. Any ideas how I can reconfigure the router to work properly?