Network Infrastructure includes networks, network devices, servers, workstations, and other devices. The software running on these devices are also the part of Network Infrastructure. To make sure your network is secure, you should make sure every time a configuration is changed or new device is added, you are not creating a hole in your security. A normal network comprise of routers, firewalls, switches, servers and workstations. A typical layout of network infrastructure devices is shown below.

The following lessons explain the Network Infrastructure devices in detail.

• Firewall

• Routers

• Hubs

• Bridges and Switches

• Modems