We need to host several servers in our building, some running the same services. To be able to do this, we needed to purchase a few additional public IP addresses. This was a quick process and we paid our ISP (Xilo) a few pounds for 6.
Annoyingly, it turned out that the router we were using (Apple Airport Express PPPoE) did not support multiple IP addresses. I tried a lot of things before finally giving up and attempting to set up pfSense.
This was actually a lot simpler than I thought it would be, and I now have a working network with several public IP’s routed directly through to internal addresses.
I won’t go through the specifics here, as there were several really good guides on the net – and a great video on YouTube that helped me through it. Needless to say though – if you are looking for a good Firewall – pfSense is a great, open-source alternative to expensive hardware.