The first step in implementing a strategy for deploying physical scanners is to select a central location to which all scanners will report in the future. In the case where there may be multiple central reporting servers, select a location with the most hosts on the local network, and preferably one that has unfettered network access to other major locations. Verify that there is sufficient bandwidth available to support a schedule structured using the method previously discussed. Then, follow this iterative process:
- Perform test scanning and remediation reporting on the local network where the reporting server is installed or is on another less critical network. A 24-bit classless inter-domain routing (CIDR) block would be sufficient.
- Review the report results and any unexpected impact on the environment.
- Adjust the system and scan parameters to compensate. Be sure that any adjustments you make are scalable to hundreds or even thousands of networks once the deployment proceeds.
- Add as many similar network ranges in the local office as possible, one at a time.
- Repeat the previous steps to validate the reports and impact on the environment. Adjust accordingly.
While waiting for a few cycles of this activity to complete in the local area, plan and coordinate the next phase of scanning over the WAN to other offices in the scope of your scanning strategy. These are offices that will not receive equipment but have the capacity to be scanned through their WAN connection without impact to operations. Again, repeat the evaluation and refinement process and update the scanning standards documentation accordingly.
As the expansion of scanning begins outside of the local office, begin generating and refining the management reports. At this stage, management will become quite curious about the results of the new system. Be sure that the reports are reconcilable and that questions about their content can be addressed. If the pre-acquisition testing has been done properly, this should be easily done with possibly minor assistance from the vendor. Having an executive sponsor who is willing to preview these reports before they go to a wider audience can help identify discrepancies and questions earlier.
At this point, as much as 75 percent of the initial zone of scanning should be deployed and processes beginning to take firm, repeatable shape. The next zone of deployment should then be planned by selecting another major office with as many good connections to other target offices. Then, repeat the gradual expansion process discussed in the previous steps.