Not Every IP Is Worth Defending Equally: Smarter Resource Allocation in Cybersecurity

In cybersecurity it’s easy to believe that blanket defense is best—scan everything, monitor everything, leave no stone unturned. But in reality, not all parts of the infrastructure carry the same weight.

A recent analysis of IP range management in the Journal of Cybersecurity by Charles Harry, Ido Sivian-Sevilla, and Mark McDermott (University of Maryland) highlights an uncomfortable truth: above a certain point, the return on investment for monitoring every IP address starts to decline sharply.

The study looked at how cybersecurity teams allocate effort across different IP ranges and found that costs rise much faster than benefits once you go beyond a certain scope. Scanning and monitoring every possible IP looks thorough on paper, but in practice, it produces diminishing returns. The researchers noted that the most useful information comes from monitoring the ranges tied to critical systems, while the outer ranges consume significant resources without adding much security value. Their findings reinforce the idea that more coverage doesn’t automatically mean better defense—it’s about where you focus that coverage.

Monitoring every IP equally wastes limited resources. A company only has so much budget and so many people, and those resources need to be directed at the most critical systems. Put another way: if you treat everything as high risk, you’re basically treating nothing as high risk.

One way to think about this is through the 80/20 principle—80% of the risk often comes from 20% of the infrastructure. These “hot zones” include external-facing apps, payment systems, and identity services. Lower-impact areas like test environments or low-sensitivity IPs don’t require the same level of attention.

Of course, this doesn’t mean ignoring the rest of the network. Broad visibility is still important, but monitoring should be tiered:

• High-value infrastructure → continuous scanning and quick alerts.

• Lower-value infrastructure → lighter monitoring, periodic checks.

It’s not about ignoring parts of the network; it’s about matching the defense to the value.

The key takeaway is that cybersecurity resources are finite. People, time, and budget can only stretch so far. Smarter allocation creates a bigger impact on reducing real risk. Cybersecurity isn’t just about building taller walls—it’s about placing them where they matter most.

A better question to ask is: Which parts of our infrastructure, if compromised, would cause the most damage? Then focus relentlessly there.