Careful with that Raspberry Pi example
"Use your raspberry Pi as a DNS cache to speed up your internet"
Careful with the instructions at that link, for they contain the lines:
server=8.8.8.8
server=8.8.4.4
which are Google's DNS servers.
P.S. In the past few years I've come across a lot of people who should know better recommending Google's DNS servers. Even in the workplace.