What is the effect of policy segmentation in network security?

Policy segmentation in network security refers to the practice of dividing the network into distinct segments, each governed by its own set of security policies. This approach is effective in creating barriers that prevent attackers from freely moving between different segments of the network once they have gained access to one part.

The reason this answer is correct lies in the principle of containment that policy segmentation enacts. When a network is segmented, even if an attacker penetrates one segment, they are restricted from easily accessing critical resources or other segments of the network. This limits their ability to spread malware or access sensitive data, effectively minimizing the potential impact of a breach.

In contrast, unlimited user access, while it might seem beneficial initially, compromises security as it creates a flat network where attackers can traverse freely if they exploit a vulnerability. Similarly, while segmentation can contribute to minimizing external attacks and improving network performance, these are not its most direct effects. The primary and most significant outcome of policy segmentation is the enhancement of security through limiting lateral movement within the network.