Network firewall with PiHole

Is it possible to setup a network level firewall with PiHole? PiHole works well as a network ad blocker, but suppose I want to route all internet with a firewall at the server end, so that the PiHole server also acts as a network wide firewall?

For this you'd have to install Pi-hole on a server that can be used as router (two physical NICs, forwarding enabled, ...). Even then Pi-hole would only be part of this solution (DNS server) but would not offer a firewall solution. This could, however, easily be added using e.g. iptables.