DHCP, VLANs, APs and IP assignements

Question

I have a debian-based isc dhcp server, that works as router/firewall too. I configured a Cambium cnPilot 610 to broadcast 2 SSIDs.

Each SSID is associated to a different VLAN. So, in the port where the AP is connected, I configured:

• VLAN 16 untagged
• VLAN 1607 tagged
• VLAN 1611 tagged

So, I configured the router interfaces this way:

auto eth2
iface eth2 inet static
address 172.18.104.254
netmask 255.255.255.0

auto eth2.1607
iface eth2.1607 inet static
address 172.22.103.250
netmask 255.255.252.0

auto eth2.1611
iface eth2.1611 inet static
address 172.22.22.250
netmask 255.255.255.0

auto eth3
iface eth3 inet static
address 200.16.31.18
netmask 255.255.255.240
gateway 200.16.31.17

I added this to my /etc/default/isc-dhcp-server file:

INTERFACES="eth2 eth2.1607 eth2.1611"

This is my /etc/dhcp/dhcpd.conf:

include "/etc/dhcp/aps";
authoritative;

shared-network wifilenguas {
    # Para los APs
    subnet 172.18.104.0 netmask 255.255.255.0 {
                default-lease-time 7200;
                max-lease-time 7200;
        pool{
                    deny unknown-clients;
                    range 172.18.104.10 172.18.104.100;
                    option domain-name-servers 172.18.104.254;
                    option domain-name "fl.unc.edu.ar";
                    option routers 172.18.104.254;
                    option broadcast-address 172.18.104.255;
        }   
    }


    # Para los docentes
        subnet 172.22.22.0 netmask 255.255.255.0 {
                default-lease-time 1800;
                max-lease-time 1800;
        pool{
            allow unknown-clients;
                    range 172.22.22.1 172.22.22.240;
                    option domain-name-servers 172.22.22.250;
                    option domain-name "fl.unc.edu.ar";
                    option routers 172.22.22.250;
                    option broadcast-address 172.22.22.255;
        }
        }

        # Para los alumnos
        subnet 172.22.100.0 netmask 255.255.252.0 {
                default-lease-time 1800;
                max-lease-time 1800;
        pool{
            allow unknown-clients;
                    range 172.22.100.1 172.22.103.240;
                    option domain-name-servers 172.22.103.250;
                    option domain-name "fl.unc.edu.ar";
                    option routers 172.22.103.250;
                    option broadcast-address 172.22.103.255;
        }
        }


}

I have the AP MAC into /etc/dhcp/aps

host AP_Aula22 {
        hardware ethernet 58:c1:7a:16:a1:86;
        fixed-address 172.18.104.10;
}

Well. The AP can get its IP perfectly. When I connect to the first SSID (associated to VLAN 1607), I get all the IP parameters perfectly and I can navigate into Internet. But when I switch to the other SSID (associated to VLAN 1611), the dhcp server gives me the same ip address, instead of some from the other subnet.

I googled a lot, but I couldn't find any similar situation.

Any suggestions??

Thanks a lot!!!