The IP address 172.23.209.0 : 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 172.23.209.0 detail
The IP address 172.23.209.0 (IPv4 Class B networks) belonging to the network 172.16.0.0 - 172.31.255.255 is written in long version -1407725312.
Color obtained mathematically from the IP address: Vibrant purple
Addresses on the same network : 172.23.209.1 172.23.209.2 172.23.209.3 172.23.209.4 172.23.209.5 172.23.209.6 172.23.209.7 172.23.209.8 172.23.209.9 172.23.209.10 172.23.209.20 172.23.209.30 172.23.209.40 172.23.209.50 172.23.209.60 172.23.209.70 172.23.209.80 172.23.209.90 172.23.209.100 172.23.209.200 172.23.209.254 172.23.209.255