What is a Firewall Mirror?

A firewall mirror, often referred to as a port mirroring or span port, is a network feature that allows the duplication of network traffic from one port or VLAN to another for monitoring and analysis. This is commonly used in security appliances to enable the inspection of data packets without interrupting the flow of traffic. By mirroring the traffic, administrators can utilize intrusion detection systems (IDS) or other monitoring tools to analyze the data for potential threats or performance issues.