Introduction: The Three Tiers of Access
An office network isn't just one big pool of IPs. It is carefully segregated into three tiers based on who is allowed to access what.
The Hierarchy
- The Internet: Public IPs. Anyone in the world can access it (like the company website).
- The Intranet: Private IPs (`10.x.x.x`). Only employees on the physical premise or using a secure VPN can access these internal HR tools.
- The Extranet: A secure 'Middle Ground'. A specific server with strict IP whitelisting that allows a trusted partner (like an accounting firm) to access *some* internal data, but not all of it.
Conclusion
Effective IP design isn't just about making things connect; it’s about ensuring they *only* connect to the right people. Audit your internal boundaries here.