UPDATE: I’ve moved my DHCP Server back to the router using DD-WRT. Having it on the server was giving me trouble within MythTV. It was unable to find the tuners, making watching TV impossible… So here is what I did, but I wouldn’t recommend it.

I followed this guide to setup a DHCP server. I first had to install the isc-dhcp-server package. Then I had to modify a few settings for the DHCP Server module of webmin since it was designed for dhcp3:

DHCP server config file: /etc/dhcp/dhcpd.conf
DHCP server executable: /usr/sbin/dhcpd
Command to start/stop/restart: /etc/init.d/isc-dhcp-server start/stop/restart
DHCP server lease file: /var/lib/dhcp/dhcpd.leases

After doing that, the webmin module works and I was able to set it up. The resulting file is setup like this:

# Internal Network
subnet 10.10.10.0 netmask 255.255.255.0 {
range 10.10.10.100 10.10.10.200;
# Home Network
group {
# My Laptop
host laptop {
hardware ethernet ab:cd:ef:g1:23:45;
fixed-address 10.10.10.10;
}
...
}
}
}