Here are the steps to enable NetFlow on a Fortinet FortiGate firewall:
- Login to the FortiGate firewall web interface. 
- Navigate to the System > Config > Network > Interfaces section. 
- Edit the interface that you want to enable NetFlow on. 
- Under the Advanced section, select NetFlow from the drop-down menu. 
- Enable NetFlow and select the version of NetFlow you want to use (version 5 or version 9). 
- Configure the NetFlow options, such as the NetFlow server IP address, the collector port, and the active timeout. 
- Click OK to save the changes. 
- Verify that NetFlow is working by checking the NetFlow statistics in the System > Monitor > NetFlow section of the web interface. 
Note: The exact steps to enable NetFlow on a Fortinet FortiGate firewall may vary depending on the specific model and software version you are using. It's recommended to consult the manufacturer's documentation for specific instructions.
