This mechanism allows network administrators to forward packets based on criteria beyond the destination IP address. For instance, traffic originating from a specific department or application can be routed along a particular path, regardless of the ultimate destination. This departs from standard routing protocols that typically make forwarding decisions solely on the destination address and routing table entries. A concrete example is directing all web traffic from the finance department through a more secure internet connection while routing other departmental traffic through a standard connection.
Its significance lies in its ability to provide granular control over network traffic flow. Benefits include optimized bandwidth utilization, enhanced security by steering sensitive data through secure channels, and improved quality of service (QoS) for critical applications. Historically, such functionality required complex network designs or specialized hardware. The introduction of this feature within the operating system simplified the implementation and management of sophisticated traffic engineering strategies.