The least accurate method for estimating the size of a deployment uses only the total of level 2 and level 3 devices:
-
Use the total of devices, including virtual routers, to estimate the number of ports and interfaces in the network. VMware, Inc. has developed the multiplier of 50 to represent the typical number of ports and interfaces per device. This multiplier assumes a split of about 30 percent routers and 70 percent switches in the network:
| Total ports and interfaces |
= |
50 * devices |
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Using total number of ports and interfaces, estimate the number of managed ports and interfaces. Assume that 35 percent of the total ports and interfaces are managed:
| Managed ports and interfaces |
= |
35 percent total ports and interfaces |
-
For example, if a network has 400 level 2 and level 3 devices, the estimate for the managed ports and interfaces is calculated as follows:
| Total ports and interfaces |
= |
50 * devices |
| = |
50 * 400 |
|
| = |
20,000 |
| Managed ports and interfaces |
= |
35 percent total ports and interfaces |
| = |
(35/100) * 20,000 |
|
| = |
7,000 |
All values that were less than one were rounded up in these calculations.
Due to the lack of specific information, this number is probably less accurate than the numbers produced by other methods and should always be discussed with network administrators.
