diff --git a/nspawn-container/examples/multicast-relay/README.md b/nspawn-container/examples/multicast-relay/README.md
new file mode 100644
index 0000000..73016b8
--- /dev/null
+++ b/nspawn-container/examples/multicast-relay/README.md
@@ -0,0 +1,149 @@
+## Create the filesystem overlay
+
+If you're going to create several nspawn containers, you can save some disk
+space by using overlayfs to use a common base. Follow the instructions in the
+unifi-utilities [documentation](https://github.com/unifi-utilities/unifios-utilities/blob/main/nspawn-container/README.md)
+for UnifiOS 3.0+ containers. I called my container `debian-base`.
+
+Next, we need an `upperdir` where the file changes are saved and a `workdir`
+where temporary file changes are saved. I'm going to create a container for
+multicast-relay, replacing the [podman container](https://github.com/scyto/multicast-relay)
+that I used prior to 3.x. An important note is that upperdir and workdir
+must not be on the overlayfs that UnifiOS uses. I opted to store this data
+on the hard drive that I use for video storage at `/volume1`.
+
+So, we have the following directories, which you need to create:
+
+- `/var/lib/machines/multicast-relay`: This will be the root directory of
+  our new container.
+- `/volume1/machines/multicast-relay/upper`: This stores the differences from
+  the base container.
+- `/volume1/machines/multicast-relay/work`: This is a temporary directory for
+  changes before they're saved to `upper`. This could possibly be on a `tmpfs`
+  mount, but I didn't want to mess with available memory.
+- `/data/custom/machines/debian-base`: This is the base container directory
+  created by following the README linked above.
+
+Do it:
+```shell
+mkdir -p /var/lib/machines/multicast-relay /volume1/machines/multicast-relay/{upper,work}
+```
+
+Now add the matching entry to your fstab. I'm not 100% sure how permanent this is,
+but I'll find out when I either reboot or do a firmware upgrade.
+
+Append this to `/etc/fstab`
+```
+overlay /var/lib/machines/multicast-relay overlay noauto,x-systemd.automount,lowerdir=/data/custom/machines/debian-base,upperdir=/volume1/machines/multicast-relay/upper,workdir=/volume1/machines/multicast-relay/work 0 0
+```
+
+If everything is good, you can `mount /var/lib/machines/multicast-relay`. If
+there's any error from that, you have some homework to do. This _should_ automount
+on reboot, but I haven't tested by rebooting my UDM Pro yet. We'll see 🤞.
+
+## Configure the container
+
+With your overlay in place, you can start the container and install your stuff.
+```
+systemd-nspawn -M multicast-relay -D /var/lib/machines/multicast-relay
+```
+
+You should now be at a root shell inside the container. I configured this all
+manually, but you can use the [script](./configure-container.sh) I created during
+my trial and error to save yourself some time. Minimal Debian doesn't have 
+`curl` or `wget`, so you can install one of those and download the script,
+or copy-paste into `vi` or something. This is left as an exercise to the reader.
+
+To escape this container, you'll have to press the cheat code given at the start
+of your session. (HINT: Press <kbd>Ctrl</kbd> + <kbd>]</kbd> 3 times.)
+
+NOTE: I didn't set the root password, which you will see in many tutorials. It
+isn't needed. The host can bypass any login prompt using `machinectl shell <container>`.
+You might want to set a root password and/or other user if you are using the 
+container as a lightweight VM.
+
+## Run the container
+
+If this is your first systemd-nspawn service, you'll need to create the config
+directory.
+
+```
+mkdir -p /etc/systemd/nspawn
+```
+
+Now create the container launch configuration in the file indicated. `multicast-relay`
+requires the ability to open raw sockets, so we grant that capability and strip the rest. Be sure you specify the interfaces you wish to use in the `Environment=` line.
+Optionally, you can specify additional `multicast-relay` options in `OPTS`
+
+```
+# /etc/systemd/nspawn/multicast-relay.nspawn
+[Exec]
+Boot=on
+Capability=CAP_NET_RAW
+Environment=INTERFACES="br0 br50"
+Environment=OPTS=
+
+[Network]
+Private=off
+VirtualEthernet=off
+ResolvConf=off
+```
+
+Once that file is in place, you're ready to enable the container on boot and run it.
+
+```
+machinectl enable multicast-relay
+machinectl start multicast-relay
+```
+
+## Troubleshooting
+
+You can view the stdout of the container in the host journal.
+
+```
+journalctl -xe
+```
+
+Output from multicast-relay itself won't be found here though. You _should_ be
+able to view a containers journal from the host, but I got an error when I tried
+suggesting the Debian container has a newer journal format than the UnifiOS host.
+
+No matter, you can just enter the container and get a root shell (no login required).
+
+```
+machinectl shell multicast-relay
+```
+
+Now, we're setting the interface and options via environment variables set on the
+host. If you want to double check that's working correctly, check the environment
+of systemd from within the container.
+
+```
+cat /proc/1/environ | tr '\0' '\n'
+```
+output:
+```
+PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
+container=systemd-nspawn
+HOME=/root
+USER=root
+LOGNAME=root
+container_uuid=c05b41ce-0995-412d-bd2d-338759b24e54
+NOTIFY_SOCKET=/run/host/notify
+container_host_version_id=11
+container_host_id=debian
+INTERFACES=br0 br50
+```
+
+You could use the same command to view the environment of our service. In this case,
+we can use the PID of `dash`, the shell script interpreter from `start.sh`.
+
+```
+root@DreamMachinePro:~# cat /proc/$(pidof dash)/environ | tr '\0' '\n'
+LANG=C.UTF-8
+PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
+INVOCATION_ID=d1cfaf43a00b4e79bcddca6a1595837c
+JOURNAL_STREAM=8:51317778
+SYSTEMD_EXEC_PID=47
+INTERFACES=br0 br50
+```
\ No newline at end of file
diff --git a/nspawn-container/examples/multicast-relay/configure-container.sh b/nspawn-container/examples/multicast-relay/configure-container.sh
new file mode 100644
index 0000000..041d01b
--- /dev/null
+++ b/nspawn-container/examples/multicast-relay/configure-container.sh
@@ -0,0 +1,40 @@
+#!/bin/bash
+
+set -eux -o pipefail
+
+# Install dependencies
+apt install -y --no-install-recommends python3 python3-netifaces git ca-certificates
+
+# Checkout latest commit of default branch of multicast-relay
+cd /opt
+git clone --depth=1 https://github.com/alsmith/multicast-relay.git
+
+# Drop a startup script
+cat <<'EOF' | tee /opt/multicast-relay/start.sh
+#!/bin/dash
+# This script adapted from scyto
+# https://github.com/scyto/multicast-relay/blob/master/start.sh
+SCRIPT_DIR=$(dirname $(readlink -f $0))
+
+echo "starting multicast-relay"
+echo "Using Interfaces: ${INTERFACES}"
+echo "Using Options --foreground " $OPTS
+python3 "${SCRIPT_DIR}/multicast-relay.py" --interfaces ${INTERFACES} --foreground $OPTS
+EOF
+
+chmod +x /opt/multicast-relay/start.sh
+
+# Install and enable a systemd service
+cat <<'EOF' | tee /etc/systemd/system/multicast-relay.service
+[Unit]
+Description=multicast relay service
+
+[Service]
+PassEnvironment=INTERFACES OPTS
+ExecStart=/opt/multicast-relay/start.sh
+
+[Install]
+WantedBy=multi-user.target
+EOF
+
+systemctl enable multicast-relay.service
\ No newline at end of file