The network size determines the time it takes to complete discovery, the memory required, and the server hardware that should be selected to support Domain Managers. Estimates of network size from network administrators are usually based on one of the following quantities:
Quantity of ports and interfaces
Quantity of routers and switches
Quantity of total devices
Quantity of managed hosts
Ultimately, the most important quantities for sizing the server hardware in a deployment are the total number of ports and interfaces and the number of the total that managed. All ports are discovered using SNMP and ICMP. Managed ports and interfaces are then monitored using SNMP and ICMP to determine status and connectivity.
After numerous deployments, VMware, Inc. has developed ratios that help estimate the number of managed ports and interfaces with a high degree of accuracy. These ratios provide conservative estimates, which are especially important in large and very large networks. Being conservative is imperative, because VMware, Inc. has determined that even in well-managed large networks, administrators can underestimate the number of ports and interfaces by 30 percent or more. Always use the multipliers in conjunction with validation, discretion, and discussions with network administrators to improve the accuracy of the estimates.