What is the primary reason to use private IP address space in an internal network?

What is the primary reason to use private IP address space in an internal network?

• A. To save cost on IP addresses.
• B. To improve external reachability.
• C. To limit exposure from external networks; private addresses are non-routable on the Internet.
• D. To avoid NAT.

Answer: (C)

Private IP address space is used inside organizations to keep internal hosts from being directly reachable from the Internet. These addresses are not routable on the global public Internet, so external networks can’t reach them directly, which reduces the exposure of internal systems to external threats. This setup also allows you to reuse the same address ranges in different sites, conserving public addresses. When external access is needed, traffic is typically translated by NAT at the network edge, turning private addresses into public ones for Internet use. The other options miss the main point: private addresses aren’t about saving money, they don’t improve external reachability, and NAT is commonly used with private space, not something to avoid.

Private IP address space is used inside organizations to keep internal hosts from being directly reachable from the Internet. These addresses are not routable on the global public Internet, so external networks can’t reach them directly, which reduces the exposure of internal systems to external threats. This setup also allows you to reuse the same address ranges in different sites, conserving public addresses. When external access is needed, traffic is typically translated by NAT at the network edge, turning private addresses into public ones for Internet use. The other options miss the main point: private addresses aren’t about saving money, they don’t improve external reachability, and NAT is commonly used with private space, not something to avoid.