guest network using tagged VLANs

[Steve Sapovits]

I'm wondering if this is possible ... I can't seem to find anything that 
really matches.

Suppose I have a wireless access point (WAP) configured just as an AP -- 
no router or DHCP functionality enabled on the WiFi device.

WAP is connected to a switch with two tagged VLANs.

Switch is connected to machine running ISC DHCP.   Connection is from a 
switch port assigned to both VLANS.

In the ISC DHCP configuration for the VLAN subnet, some rules (for 
example MAC address) are used to assign an address from one of the two 
VLAN subnets.  For example, known MAC addresses get IPs from VLAN1.  
Unknown MAC addresses get IP addresses from VLAN2.

Since different interfaces are specified as subnets in the DHCP 
configuration, I don't see that I can specify one set of rules for the 
combined (trunk) VLAN.  So what I'd end up with is two subnet 
specifications where a client address may come from either the same 
subnet or from the other VLAN subnet.  Having an address range from a 
different subnet alone seems like it might not work (configuration might 
be rejected).   Beyond that, would it then even work ...

I don't really have everything needed to actually test this, which is 
why I ask.

-- 
Steve Sapovits
steves06 at comcast.net