1.3 IP Discovery Technologies

The ZENworks discovery engine can utilize a variety of different technologies for IP-based discoveries. When more than one technology is used, the discovery engine initiates a discovery request for each technology. This is done for each target IP address. For example, if you use MAC Address, SNMP, and WMI, the discovery engine creates three requests for each target IP address. The requests are queued and the discovery engine processes five requests at a time until no requests remain. Five requests is the default. You can change the default if necessary (see Section 2.1, Configuring Discovery Settings) or override the settings in the discovery task.

Using fewer discovery technologies reduces the time required to complete the discovery task but might also reduce the amount of information received.

By default, the MAC Address, SSH, WinAPI, and ZENworks technologies are enabled; the SNMP, WMI, and NMAP technologies are disabled. You can change the default if necessary; see Section 2.1, Configuring Discovery Settings.

If more than one technology request returns information for a discovered device, the information is merged together. In the case of conflicting information, the discovery process chooses the “best” information. If a high priority discovery technology is successful and returns the information, then the other lower priority discovery technologies are aborted for better performance. For example, if WinAPI or WMI is successful, then MAC address and NMAP technologies are aborted.

IP discovery tasks require the following information:

The following table provides detailed information about the IP discovery technologies:

Table 1-1 IP Discovery Technologies

IP Discovery Technology

Functionality

Requirements

Prerequisites

WMI (Windows Management Instrumentation)

WMI is the infrastructure for management data and operations on Windows-based operating systems. Discovery issues a remote request to the WMI service on the devices identified by the IP-based discovery task to obtain information. Retrieves the OS type and version, MAC address, Network Adapters, and CPU details of the device.

For more information on WMI, see the MSDN Web site.

Because WMI is a Windows-specific technology, the requests generated from a ZENworks Server running on Linux must be routed to a Windows Proxy for processing. For more information, see Section 2.2, Designating a Discovery and Deployment Proxy Server.

  • Microsoft Windows Management Instrumentation Service to be installed and running on the target Windows device.

  • Credentials of an administrator account on the target device should be specified as Windows credentials in the discovery task. This is required for connecting to the WMI Service.

  • To authenticate by using the Windows credentials, set the value of the Network access: Sharing and security model for local accounts Local Security setting to Classic - local users authenticate as themselves. For more information on how to configure the Local Security settings, see Enabling Classic File Sharing.

  • Since the Remote WMI connection establishes a RPC connection with the target Windows device, the TCP ports 139 and 445 must be allowed by the Windows Firewall of the target device for the WMI discovery technology. For more information on how to open these ports, see Enabling File and Printer Sharing through Windows Firewall.

WinAPI

Issues a request to the registry on the devices identified by the IP-based discovery task to retrieve the OS type and version, and CPU details.

Because WinAPI is a Windows-specific technology, the requests generated from a ZENworks Server running on Linux must be routed to a Windows Proxy for processing. For more information, see Section 2.2, Designating a Discovery and Deployment Proxy Server.

  • Microsoft Remote Registry Service to be installed and running on the target Windows device.

  • Credentials of an administrator account with read privileges on the Windows registry of the target device should be specified as Windows credentials in the discovery task. This is required for connecting to the Remote Registry Service.

  • The File and Printer Sharing for Microsoft Networks option must be enabled. For more information, see Enabling File and Printer Sharing for Microsoft Networks.

  • To authenticate by using the Windows credentials, set the value of the Network access: Sharing and security model for local accounts Local Security setting to Classic - local users authenticate as themselves. For more information on how to configure the Local Security settings, see Enabling Classic File Sharing.

  • Since the Remote Registry connection establishes a RPC connection with the target Windows device, the TCP ports 139 and 445 must be allowed by the Windows Firewall of the target device. For more information on how to open these ports, see Enabling File and Printer Sharing through Windows Firewall. If the target device is in a different subnet than the Windows Proxy or the Primary server running the task, then the scope of the Firewall exception should include them.

MAC Address

Retrieves the MAC Address of the discovered device. Uses the ping and arp (Address Resolution Protocol) commands to map the IP addresses of the devices identified by the IP-based discovery task to their associated MAC addresses.

The MAC Address discovery gets only the MAC address of the device and does not give any OS information.

  • For the arp command to be successful, the target devices must reside in the same network as the ZENworks Server that performs the discovery request.

  • For the ping command to be successful, the incoming ICMP echo requests (ping) must be enabled on the device, and the ICMP echo requests and echo responses must be allowed on the network.

NMAP

Uses NMAP (Network Mapper) to retrieve the OS type and version details of the devices identified by the IP-based discovery task.

IMPORTANT:NMAP has certain known limitations. For more information on these limitations, see the NMAP Web site.

 

ZENworks

Issues a request to the ZENworks Adaptive Agent or ZENworks preagent on the devices identified by the IP-based discovery task. If the device has the ZENworks Adaptive Agent, the agent responds with the OS type and version, MAC Address, Network Adapters, CPU, managed device GUID, Management Zone GUID, Management Zone name, Adaptive Agent version, disk space, and memory details. If the device has the ZENworks preagent installed, the preagent responds with the OS type, CPU, disk space, memory, and the GUID details that should be used to register the device in the Management Zone.

 

  • The preagent is only installed on OEM devices or on devices whose registration was removed from the zone.

SNMP

Issues a request to the SNMP service on the devices identified by the IP-based discovery task. SNMP versions 2 and 1 are supported, with SNMP version 2 tried first. Retrieves the OS type and version, MAC address, Network Adapters, and CPU details.

Because the discovery process uses a Windows-based SNMP technology, requests generated from a ZENworks Server running on Linux must be routed to a Windows Proxy for processing. For more information, see Section 2.2, Designating a Discovery and Deployment Proxy Server.

  • To query a device using SNMP, the device must have SNMP enabled.

  • The SNMP community string must be specified as a SNMP credential in the Discovery Task.

  • SNMP uses the UDP Port 161. The firewall must be configured to allow access through this port.

SSH

Uses the SSH protocol to communicate with the SSH server on the devices identified by the IP-based discovery task. Depending on the device OS (Linux or NetWare), the device retrieves the OS type, OS or Kernel version, CPU, Network Adapters, and memory details.

 

  • To query a device using SSH, the device should have SSH enabled, and the username and password must be specified as General or Linux credentials in the Discovery task.