How to access modem page 192.168.0.xx from 192.168.1.xx router's network

[WillyTP]

Hello everybody... I've a network "how to" connection issue please

I'm using my provider (TIM Italia) modem/router as pure modem, with IP 192.168.0.1, with autoconnection disabled.
On the router side, I've an RT-AC87U with Merlin firmware, IP 192.168.1.1, which makes the PPPoE VDSL connection.
They're connected by wire from LAN output on the modem, WAN input on the router.

My question is: is there a way to access my modem at 192.168.0.1 (in order to see DSL line statistics, VoIP options and so on) from my network 192.168.1.xx, without enabling WiFi on the modem, placing another ethernet cable between the two (and hence on my desktop change manually IP to 192.168.0.xx class in order to access it?)

Thanks for answering!

 

[ColinTaylor]

I depends on the modem/router, quite often the modem's IP address will change to something like 192.168.100.1 when in modem-only mode.

This question has been asked before, search the forums and also the wiki.

 

[dlandiss]

I wonder what would happen if you set the LAN subnet mask on the router to 255.255.0.0?

 

[WillyTP]

Hello everybody!
Actually method suggested within the Wiki by @ColinTaylor works.

However, for curiosity's sake, why does it work like this?
Shouldn't be "WAN IP" the address automatically given by the ISP?
Why does it work by giving it a fixed address?

Thanks