8. Conclusion

This document defines IP address space for private internets that can be used by any organization without registering with IANA or an Internet registry. The three defined address blocks are:

• 10.0.0.0 - 10.255.255.255 (10/8 prefix)
• 172.16.0.0 - 172.31.255.255 (172.16/12 prefix)
• 192.168.0.0 - 192.168.255.255 (192.168/16 prefix)

The primary benefit of using these address blocks is the conservation of globally unique IP address space and the flexibility provided for enterprise internal networks. The primary cost is the potential need for renumbering if connection to the public Internet becomes necessary in the future.

Enterprises should carefully weigh their current and future needs when deciding whether to use private address space. For enterprises with no plans to connect to the Internet or only planning to connect through Network Address Translation (NAT), private address space provides a practical solution.

It is important that enterprises using private address space ensure that these addresses do not leak to the public Internet and that routers and DNS servers are properly configured to maintain appropriate separation between private address space and public address space.

As the Internet continues to grow and IPv6 is gradually deployed, the concept of private address space will continue to play an important role in network architecture design.