You may never have the occasion to set up your own DNS server, but there are compelling reasons to do so. Having your own DNS server can reduce administrative overhead and improve the speed of DNS queries, especially as your network grows. Moreover, the ease with which a DNS server can be set up with pfSense makes it that much more appealing.

It should be noted that pfSense has two separate services for DNS. Prior to version 2.2, DNS services were configurable via Services | DNS Forwarder, which invokes the dnsmasq daemon. For version 2.2 and later, Unbound is the default DNS resolver, and it is configurable by navigating to Services | DNS Resolver. New installs of version 2.2 or greater have DNS Resolver enabled by default, while upgrades from earlier versions will have DNS Forwarder enabled by default. You can still use DNS Forwarder on newer versions, but if you do, you will have to disable DNS Resolver or change the port settings for it. By default, both DNS Forwarder and DNS Resolver are configured to bind to port 53, and both services cannot bind to the same port.