Creating an IPv4 Addressing Scheme

Plan your IPv4 addressing scheme to simplify routing and IP address configuration on your internal network by following these steps. In the long run, this will simplify router configuration and reduce the complexity of troubleshooting network problems.

1. Choose one of the private address ranges for your internal networks. The 10.0.0.0/8 address space provides the largest number of networks.

2. Choose a random starting point within the private address space. For example, if you are using the 10.0.0.0/8 address space, you could choose 10.187.0.0/16 for your internal networks. Even though your private address space does not need to be unique on the Internet, using a random portion of the address space will minimize the chance for conflict with other internal networks that you might connect to in the future as a result of mergers, acquisitions, or business partnerships. Many organizations start numbering at the bottom of the address space (such as using networks numbered 10.0.0.0/24 or 192.168.0.0/24), which are likely to conflict with other private networks.

3. Allocate portions of your address space to different regional offices. Provide at least ten times the number of addresses each location is likely to require in the near future to allow for future growth and enable network administrators to use logical network numbering without needing to subnet networks for efficiency.

4. Allow each regional office to subnet that address space for their internal networks. To simplify configuration, use 24-bit subnets for each physical network segment. These networks must provide address space for both wired and wireless networks.

5. Allocate network space for remote-access clients such as employees who work from home and dial in or connect using a Virtual Private Network (VPN).