Local ip isn't in LAN IP address subnet!

Well, I recently got a new modem. Before I got the modem, port forwarding was a breeze for me. But now that I got a new modem, nothing's been working. I entered the modem's settings (by putting "192.168.0.1" in the url bar) and went to the port forwarding section. When I port forward, it asks for something called a local IP address. At first, I thought it would have to do something with 192.168.1.xxx, but whenever I type that and hit apply, I get the error "Local ip isn't in LAN IP address subnet!". This is bizarre. I've always port forwarded with the same ip address for a long time now, but for some reason it doesn't work on this new modem. The modem's brand is a CGN3ROG Hitron. If anybody could help with my problem that would be great. Thanks.

 

The gateway IP (router address) is 192.168.0.1 so any devices connected to it are like ly to have an IP address of 192.168.0.xxx as this is the same subnet.

 

How do I find this 192.168.0.xxx ip address? I know to find 192.168.1.xxx you have to go into command prompt and type ipconfig, but when I do that it doesn't show any ip addresses that start with 192.168.0.xxx

 

ipconfig/all gives you more information and is exactly the same no matter what type of network connections you have.

You should also be able to see somewhere in your router's settings what devices are attached and what IP address they have been assigned. I'm not familiar with this modem so I can't give step by step instructions sorry.

Just found this
http://setuprouter.com/router/hitron-technologies/cgn2-rog/manual-1028.pdf

EDIT by Moderator: merged posts, please use the edit button instead of double posting.