[ale] ISC DHCPD config question

[Chris Fowler]

For my network I run ISC DHCPD on my desktop.  I'm trying to solve an 
over use problem.

I have two daughters in elementary school and I need to control their 
Internet access times.   Today i locked their computers down to just one 
AP.  My idea is to unplug the AP when it is time for no Internet.

I then had another idea.

What if I set up a 192.168.3.0/24 subnet on eth0:1 and then use my 
desktop as their gateway and cron with iptables to block them.

The problem with this is that I have only one interface and if dhcp 
requests come to it how can I direct them to the correct subnet?  I 
would need to tell dhcpd that only 4 devices (via MAC) go to the 3.0 and 
the remaining are part of the 1.0.

Any ideas?

Chris