Inventory
If you were asked what new devices appeared on your network in the last 24 hours, would you be able to answer that question? If there was a catastrophic internal breach and you were asked to provide a list of authorized devices, would you be able to?
Network inventory that is always up to date and can send automated reports is imperative to a secure network. There are many pieces of software that can provide this from varying automation and cost. This software generally links assets such as computers to users, and those users can have assets such as printers, monitors, keyboards, etc. This keeps users accountable for their equipment and allows the IT department to monitor any peripheral changes to workstations.