6.2.1 Selecting your primary discovery approach
Decide whether to do entirely list-based discovery, entirely rule-based discovery, or a combination of the two.
- Organization of this subsection
(1) List-based discovery
With list-based discovery, you explicitly specify (as a discovery seed) each node for NNMi to discover.
NNMi uses tenants to support networks containing overlapping address domains. Overlapping address domains might exist in the static network address translation (NAT), dynamic network address translation (NAT), or port address translation (PAT) area in the network domain management domain. To handle such a network, NNMi uses seeded discovery to place overlapping address domains in different tenants. For details, see NNMi Help.
- Important
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- If you are using NNMi to manage VMware Hypervisor-Based Virtual Networks, see the "Tenants within Virtual Environments" help topic in the Help for Administer.
- If you plan to configure multi-tenancy, list-based discovery is the recommended discovery approach.
Benefits of using list-based discovery only include:
Provides very tight control over what NNMi manages
Supports the specification of a non-default tenant at discovery time
Simplest configuration
Good for fairly static networks
A good way to start using NNMi. You can add auto-discovery rules over time.
Disadvantages of using list-based discovery only include:
NNMi does not discover new nodes as they are added to the network.
You must provide a complete list of the nodes to be discovered.
(2) Rule-based discovery
With rule-based discovery, you create one or more auto-discovery rules to define the areas of the network for NNMi to discover and include in the NNMi topology. For each rule, you must provide one or more discovery seeds (by explicitly naming seeds or by enabling Ping sweep), and then NNMi discovers the network automatically.
Benefits of using rule-based discovery include:
Good for large networks. NNMi can discover a large number of devices based on minimal configuration input.
Good for networks that change frequently. New devices that are added to the network are discovered without administrator intervention (assuming that each such device is covered by an auto-discovery rule).
Disadvantages of using rule-based discovery include:
It is easier to confront license limitations.
Depending on the structure of your network, tuning auto-discovery rules can be complex.
If auto-discovery rules are very broad and NNMi discovers many more devices than you want to manage, you might want to delete unneeded devices from the NNMi topology and node deletion can be time consuming.
All non-seeded nodes receive the default tenant at discovery. If you want to use NNMi multi-tenancy, you must update the tenant assignment after discovery.