Setting up jrouter on a Raspberry Pi
So you want to try jrouter instead of AIR3.0 ? I think that's very cool of you.

What it's good for: Getting a few Ethernet-enabled Macs onto GlobalTalk without running AIR3.0
What it's not (yet) good for: Cohabiting with netatalk on the same computer - for now, if you want to run netatalk, it's recommended to use a separate computer.

This guide assumes you have a Raspberry Pi 4 or newer, running Raspbian (Raspberry Pi OS) Full or Lite.

Basic setup walkthrough
Step 0: Claim a network range on the GlobalTalk google sheet
Step 1: Find a URL that lists all the GlobalTalk addresses (hint: Instructions / Links, row 6)
Step 2: Find your public IPv4 address (hint: https://www.whatismyip.com/ )
Step 3: On the Raspberry Pi, run:

# Downloads jrouter
curl -O https://gitea.drjosh.dev/josh/jrouter/releases/download/v0.0.20/jrouter_0.0.20_arm64.deb
# Installs jrouter
sudo dpkg -i jrouter_0.0.20_arm64.deb

Step 4: Write a jrouter.yaml file, using a plain-text editor like nano, TextEdit, vim, VSCode, Zed, ....
You can directly edit the example installed on the Pi at /etc/jrouter/jrouter.yaml if you want.
Edit it to look like this:

local_ip: 192.0.2.1  # replace with your IP address from step 2
monitoring_addr: ":9459"
ethertalk:
  - device: eth0  # "eth0" assumes your Pi is connected via Ethernet - wifi is usually "wlan0"
    zone_name: Your Zone Name Here  # put your zone name
    net_start: 1234  # replace 1234 with the start of your network range from step 0
    net_end: 1234  # replace 1234 with the end of your network range from step 0
open_peering: true
peerlist_url: http://example.com/peers.txt  # replace with the URL from step 1

(The comments - the # on each line and text afterwards - can be deleted to make it tidier.)

Save it to /etc/jrouter/jrouter.yaml on the Raspberry Pi.
Step 5: on your internet router, set up port-forwarding of UDP port 387 to the Raspberry Pi (only UDP is needed, TCP is unnecessary)
Step 6: Now you can get the party started! On the Pi, run:

sudo systemctl enable --now jrouter

This starts jrouter and makes it automatically start on startup

Managing jrouter
To get the jrouter status page, open http://your-pi-address:9459/status in your browser.

To get the logs from jrouter:
journalctl -uf jrouter
To restart jrouter (needed if you change the configuration):
sudo systemctl restart jrouter
To stop jrouter:
sudo systemctl stop jrouter
To stop and disable jrouter:
sudo systemctl disable --now jrouter
To uninstall jrouter:
sudo apt remove jrouter