I am a bit confused here. Your router/modem will have 2 IP addresses, the first is a public IP address that the modem/router uses to communicate with the rest of the world. It is normally supplied by your ISP (unless you have bought a static IP address). The public IP address ranges inclued ALL except the private ranges (192.168.x.x, 10.x.x.x, 172.16.x.x - 172.31.255.255 plus 127.0.0.x). You then have a private IP address which allows your laptop to communicate with the modem/router. These are in the private IP address ranges (see above). As said, the modem/router will have 2 IP addresses (a private and a public) whereas your laptop will only have a private. The confusion is what IP address are you talking about? My guess is the public one for your modem/router since you say you can view the modem/router from your laptop. Unless you have bought a static IP from your ISP then the IP address will be picked up from your ISP through DHCP. Are you putting a private IP address in as the public IP address of the router? It is very unusual to have to put the public IP address in (unless you are a business and need a static IP address for MX/DNS records).