Within a company, there are many levels that must be taken into account in network security. Attacks can take place at any level and hackers are able to exploit any securi-ty gap, no matter how small. • Physical network security prevents unauthorised persons from gaining ac-cess to the various network components. • Technical security controls serve to protect the stored and transmitted data. • Administrative network security includes security policies and processes that control user behaviour. These include, for example, user identification and ac-cess rights, as well as the way in which changes to the IT infrastructure may be made. To prevent potential attackers from entering the network, strict network access control is necessary for both users and devices that connect to the net-work. • Quality antivirus software continuously scans files entering the network and protects the business from malicious software. • A firewall provides a barrier between one’s own and untrusted external net-works. Administrators configure rules that determine what traffic is blocked and allowed. Only a holistic security approach with a collaborative network security architecture that defends all layers and covers the full attack surface with all access points guarantees a secure corporate network.