A tool to enable notifications of status changes to WAN interfaces of a Unifi Dream Machine. In my case the UDM-SE, but this will work for all UDM flavours. Notifications come in the form of a UniFi Event Message, so that will be a Push Notification or Email, based upon whatever you've got configured for status notifications. Obviously if all of your WAN interfaces are down you aren't going to get a notification, but I built this tool so I got a notification when a WAN failover occurred due to my primary ISP (BT) being crap, and the connection failed over to my Starlink connection. Living in a rural location is fantastic, until it comes to dealing with telcos and the unreliable Internet services they provide.
This guide explains how to compile, deploy, and configure the WAN interface monitor on your UniFi Dream Machine (SE/PRO/MAX).
- Go installed on your development machine (Mac, Linux, or Windows)
- SSH access to your UDM-SE/PRO/MAX
- UniFi account with administrative privileges
- A new UDM user for the service to authenticate via. Ideally with least privileges, View appears to be the least available :/
# clone the repo
git clone https://github.com/andy-wilson/udm-wan-monitor.git
cd udm-wan-monitor
# Set the environment variables for cross-compilation
export GOOS=linux
export GOARCH=arm64
export CGO_ENABLED=0
# Compile the tool
go build -o udm-wan-monitor main.go
# The compiled binary will be created in the current directoryThe process is similar, just make sure to set the correct environment variables:
export GOOS=linux
export GOARCH=arm64
export CGO_ENABLED=0# Create a directory on the UDM
ssh root@[your-udm-ip] "mkdir -p /root/udm-wan-monitor"
# Transfer the compiled binary and config file
scp udm-wan-monitor config.json root@[your-udm-ip]:/root/udm-wan-monitor/SSH into your UDM and edit the configuration file:
ssh root@[your-udm-ip]
cd /root/udm-wan-monitor
# Edit the config file with your preferred editor
vi config.jsonUpdate the following values in the config file:
username: Your UniFi account usernamepassword: Your UniFi account password- Adjust any other settings as needed. You may need to alter
wan_interfacesdependent on which interfaces are configured. The default ones are correct for UDM SE/PRO/MAX.
Note: Given this needs "admin" access credentials, I'd suggest you create a View user. In the UniFi UI, head to Network-> Setting-> Admins & Users -> Create New Admin On the box on the right, select the checkbox for "Restrict to Local Access Only". Uncheck "Use a Predefined Role". Next to the Target icon, select View Only (the default is Full Management, which is bad). Next to the User icon, select "None" (anything else is bad).
Run the monitor manually first to ensure it works correctly:
# Make the binary executable
chmod +x /root/udm-wan-monitor/udm-wan-monitor
# Run the monitor with the config file
/root/udm-wan-monitor/udm-wan-monitor -config /root/udm-wan-monitor/config.jsonVerify that the application starts without errors and can correctly detect your WAN interfaces.
Create a systemd service file to run the monitor as a background service:
cat > /etc/systemd/system/udm-wan-monitor.service << 'EOF'
[Unit]
Description=UDM WAN Interface Monitor
After=network.target
[Service]
ExecStart=/root/udm-wan-monitor/udm-wan-monitor -config /root/udm-wan-monitor/config.json
WorkingDirectory=/root/udm-wan-monitor
Restart=always
RestartSec=10
KillMode=process
[Install]
WantedBy=multi-user.target
EOF
# Enable and start the service
systemctl enable udm-wan-monitor.service
systemctl start udm-wan-monitor.service
# Check the status
systemctl status udm-wan-monitor.serviceTo verify the notifications are working:
- Disconnect one of your WAN connections briefly
- Check the UniFi notifications in the web UI or mobile app
- You should see alerts for the WAN interface status change
- Check the log file at the configured path (default is
/var/log/udm-wan-monitor.log)
If you encounter issues:
- Check the logs:
tail -f /var/log/udm-wan-monitor.log - Verify the service is running:
systemctl status udm-wan-monitor.service - Try running the application manually with
-configflag - Check if your UniFi credentials are correct
- Ensure your UDM firmware is up to date
If you need to update the configuration:
- Edit the
config.jsonfile on the UDM - Restart the service:
systemctl restart udm-wan-monitor.service
If you need to update the application itself:
- Compile a new version on your development machine
- Transfer the new binary to the UDM
- Make it executable:
chmod +x /root/udm-wan-monitor/wan-monitor - Restart the service:
systemctl restart udm-wan-monitor.service