The IP address 172.31.169.0 : Class B networks
Secure IP address This IP is only local, it is not accessible from outside the network
Rating: 5
This means that the IP address is not accessible from the Internet, it is local and only accessible within the network. Everyone has the same local address (172.16.0.0 - 172.31.255.255).
Each device (laptop, printer, scanner, phone, surveillance camera, tablet, ...) has a unique local IP address assigned by the adsl box that allows the box to identify the different devices to within a local network and send the right product at the right flow.
Specifically, the adsl box has a public IP address in your case, which connects to the Internet and the box assigns a local address to all devices to identify them.
The IP address 172.31.169.0 detail
The IP address 172.31.169.0 (IPv4 Class B networks) belonging to the network 172.16.0.0 - 172.31.255.255 is written in long version -1407211264.
Color obtained mathematically from the IP address: Barney
Addresses on the same network : 172.31.169.1 172.31.169.2 172.31.169.3 172.31.169.4 172.31.169.5 172.31.169.6 172.31.169.7 172.31.169.8 172.31.169.9 172.31.169.10 172.31.169.20 172.31.169.30 172.31.169.40 172.31.169.50 172.31.169.60 172.31.169.70 172.31.169.80 172.31.169.90 172.31.169.100 172.31.169.200 172.31.169.254 172.31.169.255