Private IP routed to the internet

[cdturri]

So my internet connection was down today and when I tried to hit my cable modem after I rebooted it I got redirected to an Asus error router page (http://router.asus.com/error_page.htm?flag=3, see image). How can I disable this? I do not want my router to redirect any traffic. If the internet it's down then it should not redirect traffic and the connection should fail. In fact I think this case it's even worst case since my cable model IP it's on my local LAN. My router it's on 192.168.1.1 and my cable modem it's on 192.168.100.1. My educated guess on what happened here is that since my cable modem was off and the Asus router couldn't route to its IP (which it's on a different subnet) it tried to route that traffic to the internet and since the internet was down it displayed the "unable to connect to the Internet" error. However the whole 192.168.0.0 class C network is a private IP v4 address so it should not be routed to the internet. Am I missing something here?

I run Asuswrt-Merlin on an Asus RT-AC68U with firmware version 384.17.

 

[predatorz]

Can set "Enable WAN down browser redirect notice" in Administration, System to "No" for this

 

[cdturri]

Can set "Enable WAN down browser redirect notice" in Administration, System to "No" for this

Thanks, I somehow missed that. I have changed it to No now. Having said that this option should be applicable for WAN addresses not a private address like 192.168.100.1.