Your school or district’s network administrator is the best place to start. In general, the tech department can provide you with this information.
The best way to obtain the IP addresses is to determine the externally facing IP addresses. Another option is to contact your Internet Service provider and they can provide you the IP addresses associated with your school or district.
Your IP should be submitted as a single address or a range. Once you have your IP address or range, you can set up network redirect (IP forwarding) for your district.