I am the system administrator for a high school that wishes to allow students to use Spotify on our network. I've discovered that I need to allow for port TCP 4070, but I still need to know Spotify's public IP Address(es) that correspond to these ports. I am not willing to open up this port for all inbound / outbound traffic since students will abuse it. Please note that I found a post from 2012 regarding this similar request; however, the IP Addresses listed (126.96.36.199/21 and 188.8.131.52/21) no longer seem relevant.
Does anyone know the public IP Address range for Spotify?