Why, yes we do!
The starting point for a discussion about Discovery schedule tactics is to understand how your enterprise's IP addresses are assigned. We see three common patterns:
- By geography. Different IP address ranges are assigned to each physical location (or region) in your enterprise. For example, a campus in Mattawumkeag, Maine might have IP addresses of 10.32.x.x.
- By organization. Different IP address ranges are assigned to each organizational unit in your enterprise. For example, the finance department might have IP addresses in the range of 10.x.21.x.
- By equipment category. Different IP address ranges are assigned to different kinds of gear. For example, printers might have IP addresses of 10.x.20.x.
Note that your enterprise might use more than one of these patterns. Using the example above, if an enterprise used both the geography and the equipment category patterns, then a printer in Mattawumkeag might have an IP address of 10.32.20.44.
Once you understand how your enterprise assigns IP addresses, then you can start designing your Discovery schedule tactics. If your enterprise uses geography and organization to assign IP addresses, then your schedules can be different for each geography or organizational unit. If your enterprise uses only equipment category to assign IP addresses, then your tactics will be limited to different schedules for each equipment category.
The next point to decide is how often your CMDB needs to be updated by Discovery. This depends greatly on what you're going to use the CMDB for, and on how often changes occur. Sometimes it depends on the kind of gear as well — for example, workstations and laptops may change much more often than network printers. The most common schedule we see is weekly, often during off-hours to minimize any possible impact to the equipment or network during production times (though many run Discovery during working hours without any noticeable impact at all).
Some choose to run less often, particularly for certain categories of equipment. For example, perhaps your servers at a particular location are very stable; you might run Discovery there every two weeks or even monthly.
A few of our customers are running more often — in one case, daily (because their workstations and laptops have very short DHCP leases, and their service desk needs to keep up with the changes).
One very common pattern we see is to have Discovery schedules for different geographies running at different times, so that the Discovery runs outside of working hours at that particular location. This is particularly true for our customers with international operations, operating around the clock — there is no single "right time" for them to run a Discovery, so they tune it for each locale.
One final thought for you: in general, we'd recommend setting up very granular schedules. For example, if your enterprise uses geography and equipment category to assign IP addresses, consider setting up a different schedule for each combination of these (a Mattawumkeag, Maine Printers schedule, a Priest River, Idaho servers schedule, etc.). This is a little more work during setup, but the result is that you will have very fine-grained control and reporting of your Discoveries...
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