OK, so I have a subnet (192.168.11.0) that currently has all servers and clients on it. It's running out of addresses. So, I create a new subnet (192.168.12.0) and change my DHCP server (Fortigate ...
One subnet for the staff would include all the "trusted" ports in the office. The other subnet would be for the agents and would also include public areas like conference rooms, wireless access, ect.