I have an allocation within 44net (aka AMPRnet) and so I set up a gateway based on a Raspberry Pi 4B – well, I had one unused one! My allocation is a /29, so 6 IP addresses. The Pi setup is the Pi 4, a PoE HAT, an Ethernet USB dongle for the second Ethernet interface, and a neat 3D printed case that I have used before and which has the height for the HAT.
Software-wise it’s just Raspberry Pi OS, plus a daemon called ampr-ripd which listens for gateway announcements and sorts out routing tables. My link is to the IPIP mesh so I am not doing BGP or anything fancy.
My initial experiment used the wifi interface and I could connect to 44net via the phone / wifi AP software running on the Pi. That worked ok but really I wanted to be able to connect a couple of systems and not bother with wifi. As I had an Ethernet dongle left over from the dismantled QO100 transceiver that did the job nicely. The plan is to connect this to a small network switch offering a couple of Ethernet ports to be used on 44net. So far, the only system connected is my ageing Samsung Netbook which is is horribly slow even with Lubuntu and has a weird screen xy format. But it works nicely using telnet to access a chatroom on 44net.
The basic configuration and ideas came from https://ioclarity.ca/building-a-raspberry-pi-amprnet-ipip-gateway/. In particular, the scripts there set up the IPIP tunnel and add iptables rules.
The Pi has been set as the default DMZ host via the ISP broadband router (at which point it began to get hammered with ssh attempts which reminded me to disable password authentication!).
I have yet to get DNS names allocated so I cannot route over the wider Internet, not that this matters in particular as I can access other 44net services anyway.