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This topic contains information and specific examples about how to perform tasks in Discovery.

The following are few of the most commonly asked questions about how Discovery gathers information about assets on the network.

How Does...  
How does NetScan discover networked Windows devices? Given an IP address or an address range, NetScan pings the IP addresses and then issues a WMI query against the device. If the WMI scan fails, it then attempts to interrogate the device with a SNMP query.
Can the frequency of NetScan be controlled or scheduled? NetScan is an active discovery method and runs daily. There is currently no other scheduling mechanism available. It is also triggered each time a new IP address range is deploy to the gateway.
How does LANProbe discover networked devices? LANProbe is a passive discovery tool. It listens to the network broadcast. If it recognizes a new IP that it has not encountered before, it executes an SNMP query for that IP in order to discover the device.
How does Discovery count configuration items towards license?

Discovery counts all configuration items that are not in the retired status. They are discovered by one of the following methods: Active Directory scan (ADScan), LanProbe, NetScan, or client agent (self register). They can also be scanned by the client agent, LanProbe, NetScan, RemoteScan (WMI) using:

"SELECT count(*) as NodesCount, MAX(LastScanDateTime) as ScanDate

FROM CI WHERE Status <> 'Retired'

AND (

DiscoveryMethod in ('Self Register', 'NetScan', 'LanProbe', 'ADScan')

or ScanMethod in ('Agent', 'NetScan', 'LanProbe', 'WMI')

)"

How does Discovery identify a device?

Whenever the Discovery asset processor receives a message, it attempts to match the data received with existing configuration items.

There are 2 mechanisms available to match a CI record which depend on the method used to create the data.

Note that a record must exist, in order to be found.

For LANProbe, NetScan and ADScan data, the application uses the following parameters:

MAC address (as long as it is not a virtual MAC address) i.e. only known MAC addresses that are software generated.

Serial Number (if it exists).

Fully qualified domain name (FQDN) then Name (when a machine name is available).

IP Address (when there is no MAC address, or if it is a virtual MAC address).

For Client Agent or Import generated messages:

Prior to HEAT 2017.3 the search is hard-coded to be in the following order:

1.Client ID

2.Previous Client ID

3.MAC address (as long as it is not a virtual MAC address and it is not a laptop)

4.BIOS Guid

5.VM UUID

6.Machine Name

7.IP address

Beginning with release 2017.3 there are a few new configuration items available in the web.config file for the AssetProcessor in the AppSettings section. In this section you can specify the items you want to match on, and the order in which the match is performed based on whether the machine has a Windows or Unix OS. The entry is documented within the web.config file and is excerpted below:

<!-- When trying to find a CI based on the data in a message the following fields can be used to get a match for Windows devices

  PrevId

  MACAddress

  BIOSGuid

  VMuuid

  FQDN

  SerialNumber

  HostName

  IPAddress

 

The Client's ID will always be tried first, then you can specify the order in which the AssetProcessor will try to match using a comma separated list.

The following is the default, that is coded in the AssetProcessor

<add key="CIMatchingFieldOrder" value="PrevId,MACAddress,BIOSGuid,VMuuid,FQDN,HostName,SerialNumber,IPAddress"/>

-->

<!-- When trying to find a CI based on the data in a message the following fields can be used to get a match for Unix devices

  PrevId

  MACAddress

  BIOSGuid

  VMuuid

  FQDN

  SerialNumber

  HostName

  IPAddress

 

The Client's ID will always be tried first, then you can specify the order in which the AssetProcessor will try to match using a comma separated list.

SerialNumber is not in the default list due to the way the some UNIX platforms virtualise.

The following is the default, that is coded in the AssetProcessor

<add key="UnixCIMatchingFieldOrder" value="PrevId,MACAddress,BIOSGuid,VMuuid,FQDN,HostName,IPAddress"/>

-->

Where do you find and change gateway proxy settings when you want to deploy an agent by using DSM, and set the gateway location manually?

For an existing client, redirect to a proxy by adding a new gateway proxy server address from:

Inventory Settings tab and select the Deploy Settings quick action.

 

For Windows, to install a new client and have it report to a proxy address, download the Windows MSI package and insert the proxy address in the BaseURL parameter.

How is the configuration item type set by Discovery when importing data through SCCM?

For devices that have a client installed, the configuration item type is set to either workstation, server or mobile device depending on the osClass in the message.

If the operating system is in a virtual machine, the configuration item type is set to VirtualWorkstation or VirtualServer.

For devices returned by LANProbe, the configuration item type is set to: Unknown Device, unless the type in the device asset is a known configuration item type such as [Server], [Workstation], [VirtualServer], [VirtualWorkstation], [AccessPoint], [ESX], [FAX], [Firewall], [Generator], [Hub], [MobileDevice], [Monitor], [PeripheralDevice], [Phone], [Printer], [Rack], [Router], [SAN], [Scanner], [Switch], [UPS], [VideoConference], [VOIP]


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