Host PerimeterA firewall on a server or device that prevents external entities from using certain local resources such as a port.
Local PerimeterIt is common for an organization's internal network to have multiple zones that are each protected by a network perimeter. For example, a bank may isolate backend servers such that only specifically authorized IPs may establish a network connection.
External PerimeterThe main perimeter between an organization's local networks and the internet. This may restrict ports, applications and protocols. Traffic between an internal network and external network may also be closely monitored by security infrastructure such as an intrusion detection system.
|Overview: Network Perimeter|