Can't access router's configuration page on the second (outer) router

[Nayla Amir]

I wanted to expose my port 3000 to the internet via port forwarding. After going to my first (inner) router's (that my desktop is directly connected to) configuration page I realized that its WAN (external) parameters are as follows:

1. IP address = 172.20.1.174(this comes into private IP range 172.16.0.0 – 172.31.255.255)
2. Subnet mask = 255.255.0.0
3. Default gateway = 172.20.0.1

From 172.20.0.1 being default gateway I thought that it's my second (outer which is likely under ISP's possession) router's IP. So, I tried to access its configuration page to make double port forwarding. But in response I got TCP connection refused.

Does this mean that my ISP doesn't provide such services as port forwarding by not allowing access to the second router, or it's me who doesn't understand something? Maybe second (outer) router's configuration page does have to stay on 172.20.0.1 IP? OR maybe ISP doesn't allow to access this page from inside the network (because the are about 2^16 other IP addresses under this second router besides mine, so it would be problematic if one person could change settings for all the users).

Please do excuse me for superficial understanding of network.

 

[newtekie1]

Chances are, if you don't have the ISP provided router in your residence and just have an ethernet connection provided by your ISP, then the ISP gateway is likely shared with multiple different customers. And access to the configuration page is probably not possible.