I have some clients who need a CCTV camera in a remote location and there isn’t a budget for any kind of infrastructure at the site and we want the recording to happen back at a central server.
So my solution is a raspberry pi zero with a PoE hat at the remote location sharing the entire network and giving a frigate instance access to the PoE camera via a tailscale network.
During my setting up and testing I thought it might be possible that the network IP details change or that this little tailscale relay unit needs to be deployed into a new network as a support unit, a network audit unit, a mail in/out support dropbox etc. So I made a little script and set of instructions for anyone who wants to make their own portable support box.
The script runs at system boot and checks the network connection details and updates the tailscale network with its local network which is rout able. This means you can plug this unit into any PoE port and within minutes it is providing full network access via a tailscale network.
I have been testing this setup with a cheap ($65 Australian) Annke PoE camera and if you manually set the cameras network settings so it can’t access the internet this is a great way to plumb it back into a frigate NVR system where it can be analysed for persons or objects.
This can be setup on a raspberry pi 3/4 as well ( I have done all my testing using a Raspberry pi 4 4Gb)
Possible uses are kinda endless, mail it to your parents to fix their network, mail or install at client locations for auditing, get arrested trying to hack your school/university!
Follow the instructions below on a Ubuntu Server 22.04
Feel free to give me feedback if you run into issues! 
sudo apt update && sudo apt upgrade -y
curl -fsSL https://tailscale.com/install.sh | sh
sudo reboot
sudo tailscale up
#here you will need to copy a link into your browser and log into tailscale
sudo nano /etc/sysctl.conf
#add the following to the file
net.ipv4.ip_forward=1
net.ipv6.conf.all.forwarding=1
sudo sysctl -p
sudo nano script.sh
#paste script into this file
This is the script
#!/bin/bash
# Get the primary network interface's IP address and subnet
PRIMARY_INTERFACE=$(ip route | grep '^default' | grep -oP '(?<=dev )(\S+)')
# Fetch IPv4 address
IPV4_ADDR=$(ip -4 addr show $PRIMARY_INTERFACE | grep 'inet\b' | awk '{print $2}' | head -n 1)
# Calculate the network address from the IPv4 address
IFS='.' read -ra ADDR <<< "$(echo $IPV4_ADDR | cut -d'/' -f1)"
NETMASK=$(echo $IPV4_ADDR | cut -d'/' -f2)
if [ "$NETMASK" == "24" ]; then
NETWORK_ADDR="${ADDR[0]}.${ADDR[1]}.${ADDR[2]}.0/$NETMASK"
elif [ "$NETMASK" == "16" ]; then
NETWORK_ADDR="${ADDR[0]}.${ADDR[1]}.0.0/$NETMASK"
elif [ "$NETMASK" == "8" ]; then
NETWORK_ADDR="${ADDR[0]}.0.0.0/$NETMASK"
else
echo "Netmask not supported by the script."
exit 1
fi
# Check if IPv4 address is retrieved
if [ -z "$IPV4_ADDR" ]; then
echo "No IPv4 address found on the interface $PRIMARY_INTERFACE."
exit 1
fi
# Construct Tailscale command to advertise the IPv4 route
ADVERTISE_CMD="sudo tailscale up --accept-routes --advertise-routes=$NETWORK_ADDR"
# Execute Tailscale command
echo "Executing command: $ADVERTISE_CMD"
eval $ADVERTISE_CMD
sudo chmod +x script.sh
sudo nano /etc/systemd/system/myscript.service
#paste the following into file
#adjust the script.sh path as needed
[Unit]
Description=Run my script at startup
[Service]
Type=simple
ExecStart=/home/ubuntu/script.sh
Restart=on-abort
[Install]
WantedBy=multi-user.target
sudo systemctl daemon-reload
sudo systemctl enable myscript.service
sudo systemctl start myscript.service
Finally, if you want to be able to get to the RTSP stream from a desktop running tailscale you will need to launch tailscale with the following argument (stop tailscale first if it is already running)
sudo tailscale up --accept-routes
To get it working in home assistant you need to go into the tailscale add on config and either edit the config yaml and add the line below or scroll to the bottom of the unused settings and toggle the userspace networking setting so that it stays off. Doing this will let your home assistant see the RTSP stream in Frigate for object analysis.
userspace_networking: false