The main types of network security devices include firewalls, intrusion protection systems (IPS), unified threat management (UTM) systems, network access control (NAC), email security gateways, web application firewalls (WAF), and VPN gateways. It combines hardware, software, and expert resources to ensure network integrity and prevent breaches. A key strategy in network security is the multi-layered defense. They serve as a barrier between trusted internal networks and untrusted external networks, such as the internet. Firewalls are network. On top of the many network devices that any enterprise should have today, there are a selection of network security tools and devices that can help you defend your network.