SNMP Data Source

The SNMP (Simple Network Management Protocol) data source allows Mango to collect data from any device that implements the SNMP protocol. SNMP is the standard management protocol for network infrastructure such as switches, routers, UPS systems, printers, and many industrial devices. Mango supports SNMPv1, SNMPv2c, and SNMPv3, including both polling and trap reception.

This data source performs periodic GET requests to retrieve OID (Object Identifier) values from devices, and can also listen for asynchronous SNMP trap messages that devices send when events occur.

Overview

Property	Value
Module	mangoAutomation-SNMP
Protocol	SNMP v1/v2c/v3
Direction	Polling + Trap reception
Typical Use	Network device monitoring (switches, routers, UPS)

Prerequisites

• Network access to the SNMP-enabled device on the appropriate port (default: UDP 161 for queries, UDP 162 for traps).
• The device's MIB file (Management Information Base), which documents the available OIDs and their meanings. While not strictly required, MIB files make it much easier to find and understand the data points available on a device.
• For SNMPv1/v2c: the community string (acts as a password, default is often "public" for read and "private" for write).
• For SNMPv3: the Engine ID, username, and authentication/privacy credentials.

Configuration

Data Source Settings

Every data source requires a Name, which can be any description.

Setting	Description
Update period	How often Mango polls the SNMP device for data.
Host	IP address or hostname of the SNMP device.
Port	UDP port for SNMP queries (default: 161).
SNMP version	v1, v2c, or v3. Determines which authentication fields are shown.
Timeout	Milliseconds to wait for a response.
Retries	Number of retry attempts for failed requests.
Maximum vars per request	Controls request partitioning. A value greater than 0 splits requests into groups of this size. A value of 0 sends all OIDs in a single request.

SNMPv1 / v2c Authentication

SNMPv1 and v2c use community strings as passwords. Typically there is a read-only community string (often "public") and a read-write community string (often "private"). Mango sends the write community string when setting point values and the read community string during normal polling.

SNMPv3 Authentication

SNMPv3 provides stronger security with user-based authentication and optional encryption.

Setting	Description
Engine ID	The SNMP engine identifier. Must be 5 to 32 bytes, entered as hex starting with 0x.
Context engine ID	Usually the same as the Engine ID unless the device uses a separate context engine.
Security name	The SNMPv3 username.
Auth protocol	Authentication protocol (e.g., MD5, SHA).
Auth passphrase	Password for authentication.
Privacy protocol	Encryption protocol (e.g., DES, AES128).
Privacy passphrase	Password for encryption.

Valid hex format for Engine IDs: 0x80:00:00:09:03:dc:ce:c1:ff:c9:dc (colon-separated).

Host Testing

Before adding data points, use the Host test section to verify connectivity and check individual OID values. Enter an OID and click "Get OID value" to send a single SNMP GET request using the current configuration settings. If successful, the value is displayed. If not, an error message describes the problem (e.g., timeout, authentication failure, or unknown OID).

Data Point Configuration

Setting	Description
OID	The Object Identifier to request from the device (for polling) or to match in incoming traps. Example: 1.3.6.1.2.1.1.3.0 (system uptime).
Data type	The Mango data type for the point: Numeric, Binary, Multistate, or Alphanumeric. Values are automatically converted.
Binary 0 value	For binary points, the SNMP value that should be interpreted as 0 (false). All other values will be true.
Set type	The SNMP data type to use when writing values back to the device. Select "(not settable)" for read-only points.
Polling	Whether to include this OID in regular GET requests, or only receive values via traps.
Multiplicand / Augend	For numeric points, a linear transformation: displayed = (raw * multiplicand) + augend.

SNMP Network Discovery

Mango includes a built-in SNMP import tool that can scan networks and automatically discover SNMP devices and their available data points.

Using the SNMP Import Tool

1. Navigate to Administration > Admin Home > Utilities and open the SNMP Import tool.

2. Click + NEW DATA SOURCE to create a data source for the device you want to scan.

3. Enter the scan settings including the device IP address, SNMP version, and community string. Click the scan button to discover the device.

4. Return to the SNMP Point Import tool and select the device from the data source list. If you have a MIB file, upload it to help Mango interpret the discovered OIDs. Click START SNMP WALK to enumerate all available OIDs on the device.

5. Select the data points you want to add and switch to the PREVIEW AND CREATE POINTS tab. Click CREATE MANGO POINTS to add them to your data source.

After the points are added, you can use the Bulk Editor to modify point settings such as names, logging intervals, and text renderers.

Common Patterns

Monitoring Network Switches

A typical use case is monitoring switch port status, traffic counters, and error rates. Use the IF-MIB (interface MIB) OIDs:

• 1.3.6.1.2.1.2.2.1.8.X -- Interface operational status (up/down) for port X
• 1.3.6.1.2.1.2.2.1.10.X -- Inbound octets (bytes received) for port X
• 1.3.6.1.2.1.2.2.1.16.X -- Outbound octets (bytes sent) for port X
• 1.3.6.1.2.1.2.2.1.14.X -- Inbound errors for port X

UPS Monitoring

Many UPS systems support the UPS-MIB. Common OIDs include:

• 1.3.6.1.2.1.33.1.2.1.0 -- Battery status
• 1.3.6.1.2.1.33.1.2.7.0 -- Battery charge remaining (%)
• 1.3.6.1.2.1.33.1.3.3.1.3.1 -- Input voltage
• 1.3.6.1.2.1.33.1.4.4.1.2.1 -- Output power

Receiving SNMP Traps

To receive trap notifications, create data points with Polling set to "Trap only" and set the OID to match the expected trap OID. Configure the device to send traps to the Mango server's IP address on port 162. Mango will update the point value each time a matching trap is received.

Troubleshooting

Timeout Errors

If host testing or polling results in timeouts:

1. Verify network connectivity -- confirm you can reach the device (ping, traceroute).
2. Check the community string -- an incorrect community string will cause the device to silently ignore the request, appearing as a timeout.
3. Verify the SNMP version -- some devices only support v2c or v3.
4. Check firewall rules -- ensure UDP port 161 is open between Mango and the device.
5. Try a standalone SNMP tool -- use snmpget or snmpwalk from the command line to isolate whether the problem is with Mango configuration or network access.

No Values Returned

If the host test succeeds but data points show no values:

1. Verify the OID -- ensure it exactly matches the device's MIB, including the trailing instance identifier (e.g., .0 for scalar values).
2. Check the data type -- a mismatch between the Mango data type and the actual SNMP value type can cause conversion failures.
3. Check the polling setting -- ensure the point is set to poll (not trap-only) if you expect regular updates.

SNMPv3 Authentication Failures

1. Verify the Engine ID is correct and properly formatted as hex with 0x prefix.
2. Ensure the security name, auth protocol, and auth passphrase exactly match the device configuration.
3. If using privacy (encryption), verify the privacy protocol and privacy passphrase as well.
4. Some devices require the context engine ID to be set separately from the engine ID.

Related Pages

• Data Sources Overview — General data source and data point concepts
• Modbus Data Source — Another widely used polling protocol for industrial devices
• Data Source Performance — Tuning poll periods and monitoring for aborted polls
• BACnet Data Source — Building automation protocol with similar network device discovery features