ALVAO SNMP Network Discovery
This extension module uses SNMP protocol to scan network devices in a computer network, like network printers, routers, switches, etc. It consists of an SNMP Scanner application running on one or more Windows Server machines within your network infrastructure. The application regularly scans the configured IP address space, and for each scanned device it either updates or creates an object in the Objects page.
Technical requirements
- ALVAO Asset Management
- Alvao REST API
- Windows Server
- SNMP on a .NET Runtime 8 machine (SaaS and on-premise customers)
Installation
- Install the AlvaoSnmpScanner.msi application on a Windows Server machine, which is in a local network with the devices you want to regularly scan.
- In the appsettings.json file, set:
- BaseUrl - url of the Alvao WebApp, e.g,
https://contoso.onalvao.com/Alvao. - UserName and Password of an application account for basic authentication, or ClientId of the ME-ID application and application credentials. The used user (account) needs to have Asset Management Administrator permission.
- IP address ranges (from/to) - the number of IP ranges is unlimited.
- Enter all SNMP authentication methods for devices that may appear on the network.
- BaseUrl - url of the Alvao WebApp, e.g,
- Start the service.
- On the Objects page, check the found devices in the Found network devices folder.
You can turn off device pinging in the configuration file. (If PING is not allowed by your firewall, the scanner will not find anything. You need to turn off PING in the service settings.)
Operation
See the map for determining the type of object based on device description.
Existing devices are identified in Asset Management based on:
- Device MAC address
- Network name
- IP address
The SNMP last scan object property contains a timestamp indicating when the SNMP scanner last found the device in the network.
Some property values of the objects created by the scanner are locked and cannot be manually changed. If you want to turn an object to manual tracking unlock its properties by clearing the SNMP scan property value. The scanner will no longer update such objects.
When scanning printers, you will get toner values (percentages) separated by commas, order of these values is determined by SNMP Object Identifiers (OIDs). While these values typically represent toner status, they may also indicate other factors such as drum wear, transfer kit usage, etc.
ALVAO object property mapping
Computer
| AM Property | SNMP OID | Example Value | Logic |
|---|---|---|---|
| Hostname | 1.3.6.1.2.1.1.5.0 (sysName) | NTB74 / NTB74.alc.local | Set only during object creation. FQDN based on settings (WA-Administration -> State the domain name). |
| IP address | — | 192.168.0.38 | Value of the currently scanned live IP address. |
| Description | 1.3.6.1.2.1.1.1.0 (sysDescr) | Hardware: Intel64... Software: Windows... | — |
| Total storage capacity (GB) | — | 474 | Calculated from 1.3.6.1.2.1.25.2.3 (hrStorageTable) - SUM(hrStorageSize x hrStorageAllocationUnits) WHERE hrStorageType=1.3.6.1.2.1.25.2.1.4. |
| Number of logical cores | — | 8 | COUNT(hrProcessorTable). |
| RAM size (GB) | 1.3.6.1.2.1.25.2.2.0 (hrMemorySize) | 32 | Value read from SNMP converted to GB. |
| Operating system | — | Windows | Determined from sysDescr. Windows |
| SNMP scan | — | Yes | Property locks values read from SNMP for synchronization. |
| SNMP last scan | — | 2024-01-08 19:23:31+01:00 | Date and time of the last scan in the time zone where the scanner is running (yyyy-MM-dd-HH:mm:ss%K). |
Printer
| AM Property | SNMP OID | Example Value | Logic |
|---|---|---|---|
| Hostname | 1.3.6.1.2.1.1.5.0 | HPLaserJet475 | Only during object creation. |
| IP address | — | 192.168.0.154 | Value of the currently scanned live IP address. |
| Description | 1.3.6.1.2.1.1.1.0 | HP ETHERNET MULTI-ENVIRONMENT... | — |
| Model | 1.3.6.1.2.1.25.3.2 | HP LaserJet 400 color MFP M475dn | Used if hrDeviceTable contains exactly one record. |
| Toner level | 1.3.6.1.2.1.43.11.1 | 64, 17, 92, 8 | prtMarkerSuppliesLevel of all toners separated by commas. |
| Device status | 1.3.6.1.2.1.25.3.2.1.5.1 | running | Device state: Up, Down, Warning, Running. |
| Printer status | 1.3.6.1.2.1.25.3.5.1.1.1 | idle | Printer state: idle, printing, warmup. |
| Error status | 1.3.6.1.2.1.25.3.5.1.2.1 | lowPaper | Error status: low Paper, noPaper, noToner, door Open, jammed, offline. |
| SNMP scan | — | Yes | Property locks values read from SNMP. |
| SNMP last scan | — | 2024-01-08 19:23:31+01:00 | Date and time of the last scan. |
Active Network Element
| AM Property | SNMP OID | Example Value | Logic |
|---|---|---|---|
| Hostname | 1.3.6.1.2.1.1.5.0 | Mikrotik | Only during object creation. |
| IP address | — | 192.168.0.27 | Value of the currently scanned live IP address. |
| Description | 1.3.6.1.2.1.1.1.0 | RouterOS RB951Ui-2HnD | — |
| RAM size (GB) | 1.3.6.1.2.1.25.2.2.0 | 0.131 | Value read from SNMP converted to GB. |
| SNMP scan | — | Yes | Property locks values read from SNMP. |
| SNMP last scan | — | 2024-01-08 19:23:31+01:00 | Date and time of the last scan. |
Unknown Device
| AM Property | SNMP OID | Example Value | Logic |
|---|---|---|---|
| Hostname | 1.3.6.1.2.1.1.5.0 | DRTX485 | Only during object creation. |
| IP address | — | 192.168.0.58 | Value of the currently scanned live IP address. |
| Description | 1.3.6.1.2.1.1.1.0 | Cisco IOS Software... | — |
| SNMP scan | — | Yes | Property locks values read from SNMP. |
| SNMP last scan | — | 2024-01-08 19:23:31+01:00 | Date and time of the last scan. |