Preparing devices for discovery

In order for WhatsUp Gold to properly discover and identify a device, the device must respond to the protocols that WhatsUp Gold uses during discovery.

Preparing devices to be discovered

To discover that a device exists on an IP address, WhatsUp Gold uses the following methods:

Ping (ICMP)
Scanning for open TCP port

If a device does not respond to ping or TCP requests, it cannot be discovered by WhatsUp Gold. We recommend ensuring that all devices respond to at least one of these types of requests.

When using TCP port checks, discovery checks the ports listed in the following table.

Port	Description
9	Discard
21	FTP
22	SSH
23	Telnet
25	SMTP
80	HTTP
123	NTP
135	Microsoft COM RPC
137	Microsoft File and printer sharing
138	Microsoft File and printer sharing
139	Microsoft File and printer sharing
445	Microsoft File and printer sharing
500	Microsoft authentication
1900	UPnP

Preparing devices to be identified

After WhatsUp Gold discovers a device on an IP address, it queries the device to determine its manufacturer and model, components (such as fans, CPUs, and hard disks), operating system, and specific services (such as HTTP or DNS). To gain this information, WhatsUp Gold uses a combination of SNMP and WMI.

At a minimum, we recommend that important devices be configured to respond to SNMP requests. For information about how to enable SNMP on a specific device, consult that device's documentation.

Alternatively, WhatsUp Gold can gather information about Windows computers using WMI. In most cases, however, the information available via WMI is also available via SNMP. Because SNMP requests are more efficient than WMI requests, we recommend using WMI only when SNMP cannot be enabled or does not provide the same information as WMI.

Note: 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 that the appropriate ports are open on the firewall to allow WhatsUp Gold to communicate via SNMP and WMI. For more information, see Troubleshooting SNMP and WMI connections.