The network is that three AccessPoint devices connect to switch in ports GE0/0/18, GE0/0/19 and GE1/0/19, and configure different VLANs, then connect these devices to firewall who will send through his own DHCP server IP address to APs. But when the customer connects a computer in any VLAN1 ports membership, the device receives an IP from DHCP server and this shouldn't happen.
Network topology:
