I used to use Amahi, and Amahi by default has a built-in DHCP and DNS servers switched on.
Now, I removed Amahi, and am assembling my own home server using Ubuntu server.
My setup: an ADSL modem / WiFi router, a server connected to it with Ethernet cable, and a number of clients (from 2 to 5 normally) connecting over WiFi.
The router has built-in DHCP, and I normally use some external (not ISP's) DNS addresses, like Google's or OpenDNS'.
Does it make sense setting a separate DHCP on the server machine? Setting it as a DNS cache for the LAN?