Out of the Box, the ServiceNow Discovery application can discover a vast amount of devices. The application can find devices that connect to your network as well as any running software. It can discover anything from Windows desktops and servers, Linux and UNIX servers, through to printers, storage devices, routers, and switches.
Although the Discovery application caters for the majority of "common" devices, there are many other network attached devices that may be a little more obscure, and you may not be certain if they can actually be discovered at all. As a result, Technical Support is frequently asked questions of this nature concerning Discovery:
"Can Discovery discover this device? Manufacturer: x — Model: x"
Although this sort of question appears to be straight forward, I always request that the customers ask themselves a different type of question, which is…
"Does this device actually support a protocol that is supported by Discovery?"
As Discovery is an agentless product, Administrators do not need to install "agent" software on each device for it to be discovered.
Discovery uses standard Protocols and Ports to discover your devices. If the device supports one of these supported Protocols, then we should be able to obtain rudimentary information from the device.
For example:
If a customer has a legacy Compaq AlphaServer running Tru64 UNIX, we can use the Discovery application even though it is not supported by Discovery OOB.
Like most UNIX Operating Systems, Tru64 UNIX supports SSH and therefore with a little work; creating Classifiers, Probes, and Sensors, it should be possible to obtain the information required from such a device, and populate it into the CMDB via Discovery.
Life becomes more interesting when a device supports the SNMP Protocol . Starting with the Fuji release, we now support over 2,000 SNMP OIDs (Object Identifiers), and this number has been increasing steadily with every new release, as we cater for new and legacy devices.
Of course, not every device that has been released will be catered for. ServiceNow supports any device that we can talk to on our protocols with our base classification.If we do not support such a device, it is always worth checking with the manufacturer to see if they have MIBs/OIDs that can be downloaded for a specific device, which can then be installed onto your instance.
You can check if your SNMP devices are supported OOB by going to Discovery Definition > CI Classification > SNMP System OIDs
You can easily check using the Manufacturer and Model of devices displayed (you may need to personalize the list to add these), and you can then filter your search against the devices.
With a little configuration massaging we can uncover many legacy devices. One example was a customer who had a legacy Telephone Exchange, which happened to support SNMP — after a few hours of work (and obtaining the MIBs/OIDs from the manufacturer), they managed to get it Discovered.
Remember; don't start with asking if your device is Discoverable, but if your device supports a protocol that is supported by Discovery.
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