Discovery
Getting the Most from Your Scan
DiscoveryGetting the Most from Your Scan
This section includes some pre-discovery tips and preparation that will make your network and device discovery scan more effective.
Discovery Basics. Understand the basic elements needed for discovering your network and devices.
Goals of discovery:
Tip: After you add monitoring to a device from Discovered Network view you manage it (clone, delete, curate its monitoring scheme, and so on) from My Network view. For example, monitored devices can only be deleted from WhatsUp Gold using the device management actions available in My Network.
Effectiveness and richness of information returned from network and device discovery is dependent on:
Credentials associated with the scan profile enable the Discovery Service to query management objects, platform attributes, and configurations on the device.
WhatsUp Gold gathers performance metrics from platform and proprietary MIBs using SNMP, from devices running Windows using WMI, from Linux and UNIX machines using SNMP and SSH, and VMware-specific host and VM metrics using VMware credentials to query vCenter, Windows credentials for accessing Hyper-V hosts, and so on. When connectivity to management services such as these is available by way of open network routes, ports, and appropriate credentials, the Discovery Service can provide a more complete set of default health and performance monitors to the discovered device.
If your network composition changes frequently, you can apply periodic scans to ensure freshness of information.
Note: As it scans, WhatsUp Gold Discovery must adapt to twist and turns in your site's network topology and overall configuration. Connectivity to management services and associating the proper credentials list with the scan profile are key to an effective scan that returns rich information.
Ensure Devices Can Be Reached. Devices need to be reachable and powered on for rich discovery information.
WhatsUp Gold attempts to discover devices on your network using ping (ICMP) and by scanning for open TCP ports. Check to see if network devices respond to one or both of these request types before beginning discovery.
If a firewall exists between WhatsUp Gold and the devices to be discovered or if the Windows firewall is enabled on the computer where WhatsUp Gold is installed, make sure the appropriate ports are open to allow WhatsUp Gold to communicate via SNMP and WMI.
Use Credentials for Cloud Services, Hypervisors, and Management Hosts. For accurate tracking of parent-child relationships (virtual, cloud, storage, wireless, and more) these credentials are required for your Discovery scan.
Sometimes devices monitored by WhatsUp Gold are running within a cluster or deliberate deployment pattern. For these cases (virtual, wireless, storage, cloud, and more) it is best practice to first discover the management host or service with the appropriate credentials.
Ensure Devices Have SNMP/WMI Capability. SNMP/WMI needs to be configured/enabled.
Devices should be configured to respond to SNMP requests whenever possible. Alternatively, at discovery time, WhatsUp Gold can also gather information about Windows devices using WMI.
Important: You can add an SNMP agent (Windows service) from the Turn Windows Feature On or Off dialog for your current Windows device. In most cases, this Windows feature will already be enabled.
Note: In most cases, the information available using WMI is also available using SNMP. Where SNMP requests are more efficient than WMI requests, we recommend using SNMP for discovery.
Tip: For the best discovery results, configure all of the credentials used by devices on your network prior to initiating a discovery scan.
After WhatsUp Gold discovers a device, it uses SNMP MIB or WMI (Windows Management Instrumentation) data recorded on that device to gather any appropriate device properties and configuration information. The information it collects enables WhatsUp Gold to identify the device and includes but is not limited to:
Discover Virtual Hosts/VMs from the Top...Down. Specify servers (like vCenter) and hypervisors in your discovery scan.
When you discover virtual resources, include IP addresses of vCenters or hypervisors in your scan specification rather than individual VMs. WhatsUp Gold becomes aware of individual virtual machines through managing elements (such as vCenters, Hyper-V hosts, and standalone hypervisors) as part of the discovery process.
When including virtual environments in your discovery scan, follow these guidelines:
Important: To ensure that VMware vCenter, cluster, datacenter, hypervisor, and virtual machine relationships are recognized by WhatsUp Gold and later reflected on the Network Map, you must apply/update monitoring (Start/Update Monitoring) to both the managing elements, the hypervisors, and the associated the virtual machines after discovery.
Before you invoke a discovery scan on your virtual environment, check that you have these:
VMware. Valid VMware credentials are used. VMware Tools are also required.
Tip: If you delete a vCenter from WhatsUp Gold, applicable host/guest relationships will not be recognized. In order to retain these relationships, delete the host as well, then rediscover the host and add it back into WhatsUp Gold.
Hyper-V. Hyper-V devices are discovered when valid Windows credentials are used. Groups and users for passing WMI management objects must be in place. Host OS Application firewalls must align with default Hyper-V firewall rules.
The appropriate Windows users or groups must be configured to allow access to the following WMI namespaces:
The following firewall exceptions must be created:
WMI communications use a random port between 1024 and 65535 per Microsoft Windows specifications. The actual port used is determined by the remote machine. The port number range is based on the operating system being queried. The administrator can reduce or increase the range in most Windows operating systems.
WhatsUp Gold attempts discovery using Windows credentials in priority order. The first credential used that is allowed any WMI access is selected. However, if that credential does not have access to each of the required namespaces discussed previously, Windows is successfully detected, but other device details which require additional namespace access fail. The result is the target device is discovered as a Windows device, but is not recognized as a Hyper-V Host.
Note: Procedures for configuring conditions for successful Hyper-V device discover may vary depending on core versus full installation as well as the operating system on which the configuration is being performed.
When you run a discovery scan, it is best to configure your scan to learn about VMware hypervisors and virtual machines through management services (such as VMware vCenter). In unmanaged virtual environments with stand-alone hypervisors (with just VMware ESXi, for example), you can discover hypervisors individually.
When hosts are managed by vCenter.
Discovering your virtual resources by way of vCenter is the preferred approach.
Note: You might find a vCenter to be running on a VM that it (the vCenter) manages. For example, this could be the case Virtual section of the Device Card reveal that the device is running a virtual machine, but the role of the device is vCenter.
Discover and add monitoring to a vCenter and its managed elements
On My Network Map with the Virtual Overlay selected (
) lines of association show relationship between hosts and virtual machines and hosts to their vCenter.
Tip: If you delete a monitored vCenter from the WhatsUp Gold Network Map, the existing host/guest relationships between its managed virtual hosts and virtual machines will no longer be obvious to WhatsUp Gold. This can also impact the continuity of monitoring and logging. To retain continuity of information and host/guest relationships with WhatsUp Gold after a vCenter deletion, delete each virtual host, re-discover, and from the Discovered Devices Map, use Update Monitoring button to restore these relationships.
When hosts/hypervisors (ESX/ESXi) are run standalone (unmanaged).
For this scenario, your Credentials Library (SETTINGS > Libraries > Credentials) must include the WhatsUp Gold VMware credential for the VMware host you want to discover.
Discover and add monitoring to stand-alone ESX/ESXi hosts
Specify DNS hostname or IP address for Hyper-V hosts when discovering Hyper-V environments.
For this scenario, your Credentials Library (SETTINGS > Libraries > Credentials) must include the WhatsUp Gold Hyper-V credential for the Hyper-V host you want to discover.
Discover and add monitoring to Hyper-V hosts and associated virtual machines
Expand Your Scan to Include Storage Devices. Expands scan reach to include all storage resources (as reported back from SMI-S interface, for example).
WhatsUp Gold can discover and monitor storage devices, though additional considerations must be made to successfully do so. These include but may not be limited to the device's manufacturer, applied credentials, and assigned roles. The combination of such attributes will determine the specific data points WhatsUp Gold is able to retrieve and on which it can report.
WhatsUp Gold uses SNMP and SMI-S credentials to discover and monitor storage devices within your network environment. Please ensure you have created valid credentials applicable to the storage devices you wish to monitor.
Tip: Consider discovering storage devices using either an IP range or a seeded address scan. Discovering a storage node as a single device might not gather the complete set of available information that describes the device.
Please note the following additional guidelines specific to NetApp FAS series storage devices:
Note: There is no need to install a separate agent to discover or monitor EMC storage devices.
Expand Your Scan to Include Wireless. Expands scan reach to include WLAN access points distributed over different subnets.
It is best practice to discover using credentials for WLAN controllers. WhatsUp Gold network discovery uses these credentials to gather detailed information about WLAN access points.
You can create a regular scanning interval to detect and update active end-stations connected to your access points using the Schedule tab in the IP Address Scan wizard.
Note: In your discovery scan you must elect to Expand Scan to Include Wireless Environments. (This will enable discovery to include WLAN access points distributed over different subnets).
Your ability to manage wireless infrastructure devices is determined by your user rights. To view data on this dashboard, you must have the Access Wireless user right enabled. For the ability to actively manage wireless infrastructure devices as well as include, exclude, or manage rogues, the Configure Wireless option must be selected as well.
To see a video presenting quick tips for discovering devices, please click here.
Tip: In addition to being a powerful tool that enables you to discover, query, and assign monitors to your connected-devices, regular scans help keep the picture of your network current. Seeded discovery scans can help find seldom-used, forgotten, misconfigured, or even rogue devices.
Note: Given appropriate credentials, Discovery also reveals devices that qualify for environment-integrated monitoring (Analyze menu > WhatsUp Gold Add Ons). WhatsUp Gold Add Ons provide optimized visualization, logging, reporting, and monitoring for specific environments and deployment patterns and much more (Virtual, NTA, CM, Application Monitoring, and Wireless, for example).
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See Also Handling Shared Addresses (Merge Devices) Exclude a List of IP Addresses |