Monitor SNMP Network Devices with OpenTelemetry Collector

Overview

Use the OpenTelemetry (OTel) Collector to collect metrics from SNMP-enabled network devices, such as firewalls, routers, and switches, and send them to SigNoz.

The Collector's snmp receiver polls each device on a fixed interval. It reads the Object Identifiers (OIDs) you list and converts each value into a metric. The receiver has no built-in metric set, so you decide which OIDs to collect and how to name them.

The example config in this guide collects device uptime and per-interface traffic, errors, and link status. These OIDs come from the standard SNMPv2-MIB and IF-MIB, which most network devices support.

Prerequisites

• SNMP enabled on each device, with an access rule that allows queries from the Collector host's IP address.
• The SNMP community string (SNMPv2c) or user credentials (SNMPv3) configured on the device.
• The OpenTelemetry Collector contrib distribution (install guide). The SigNoz Collector also includes the snmp receiver.
• An instance of SigNoz (either Cloud or Self-Hosted).

How SNMP polling works

The receiver pulls data: the Collector sends a request to each device on every collection_interval. The Collector host needs a network path to each device it polls.

If your devices sit in a network segment that your current Collector cannot reach, run a second Collector inside that segment. That Collector polls the devices inside the segment and forwards the metrics to SigNoz over OTLP, so one outbound connection crosses the network boundary:

Devices → Collector in the same segment → SigNoz (OTLP over HTTPS)

Open these paths:

• UDP 161 from the Collector host to each device.
• HTTPS 443 from the Collector host to SigNoz Cloud, or port 4318 to your self-hosted SigNoz.

Send SNMP metrics to SigNoz

Step 1: Check that the device responds

Before you change the Collector config, run a query from the Collector host to confirm that it can reach the device. This example uses snmpget from the Net-SNMP tools and reads the device name:

snmpget -v2c -c <community-string> <device-ip> 1.3.6.1.2.1.1.5.0

If the shell reports snmpget: command not found, install the Net-SNMP client tools: sudo apt install snmp on Debian or Ubuntu, or sudo dnf install net-snmp-utils on RHEL or Fedora.

For SNMPv3, pass the user and credentials instead of a community string:

snmpget -v3 -u <snmp-user> -l authPriv -a SHA -A <auth-password> -x AES -X <privacy-password> <device-ip> 1.3.6.1.2.1.1.5.0

A working device returns its name:

SNMPv2-MIB::sysName.0 = STRING: fw-edge-01

Verify these values:

• <community-string>: The device's read-only SNMPv2c community string.
• <device-ip>: The IP address or hostname of the device.
• <snmp-user>, <auth-password>, and <privacy-password>: The SNMPv3 user and passwords configured on the device.

If the command prints Timeout: No Response, fix access before you continue. See Troubleshooting.

Step 2: Configure the snmp receiver

Add this receiver to the receivers section of your existing Collector config. Do not replace the whole file. It polls one device with SNMPv2c every 60 seconds:

receivers:
  snmp:
    endpoint: udp://<device-ip>:161
    version: v2c
    community: ${env:SNMP_COMMUNITY}
    collection_interval: 60s
 
    resource_attributes:
      device.name:
        scalar_oid: "1.3.6.1.2.1.1.5.0" # SNMPv2-MIB::sysName
 
    attributes:
      interface.name:
        oid: "1.3.6.1.2.1.31.1.1.1.1" # IF-MIB::ifName
      direction:
        enum: [receive, transmit]
 
    metrics:
      snmp.system.uptime:
        description: Time since the device's network management agent last restarted.
        unit: cs
        gauge:
          value_type: int
        scalar_oids:
          - oid: "1.3.6.1.2.1.1.3.0" # SNMPv2-MIB::sysUpTime
            resource_attributes: [device.name]
 
      snmp.interface.io:
        description: Bytes received and transmitted on each interface.
        unit: By
        sum:
          aggregation: cumulative
          monotonic: true
          value_type: int
        column_oids:
          - oid: "1.3.6.1.2.1.31.1.1.1.6" # IF-MIB::ifHCInOctets
            resource_attributes: [device.name]
            attributes:
              - name: interface.name
              - name: direction
                value: receive
          - oid: "1.3.6.1.2.1.31.1.1.1.10" # IF-MIB::ifHCOutOctets
            resource_attributes: [device.name]
            attributes:
              - name: interface.name
              - name: direction
                value: transmit
 
      snmp.interface.errors:
        description: Packets that could not be received or transmitted because of errors.
        unit: "{packet}"
        sum:
          aggregation: cumulative
          monotonic: true
          value_type: int
        column_oids:
          - oid: "1.3.6.1.2.1.2.2.1.14" # IF-MIB::ifInErrors
            resource_attributes: [device.name]
            attributes:
              - name: interface.name
              - name: direction
                value: receive
          - oid: "1.3.6.1.2.1.2.2.1.20" # IF-MIB::ifOutErrors
            resource_attributes: [device.name]
            attributes:
              - name: interface.name
              - name: direction
                value: transmit
 
      snmp.interface.oper_status:
        description: Operational state of each interface. 1 is up, 2 is down.
        unit: "1"
        gauge:
          value_type: int
        column_oids:
          - oid: "1.3.6.1.2.1.2.2.1.8" # IF-MIB::ifOperStatus
            resource_attributes: [device.name]
            attributes:
              - name: interface.name

Verify these values:

• <device-ip>: The IP address or hostname of the device. Keep port 161 unless the device's SNMP agent listens on a different port.
• SNMP_COMMUNITY: An environment variable that holds the device's read-only community string. You set it in Step 3. The ${env:SNMP_COMMUNITY} reference keeps the secret out of the config file.

Keep the device.name resource attribute, even for a single device. The receiver does not add the device address to the metrics, so without device.name you cannot tell devices apart in SigNoz.

To poll several devices, use SNMPv3, or collect other OIDs, see Customize the setup.

Step 3: Enable the receiver and restart the Collector

The install guide already configures an otlphttp exporter that sends data to SigNoz. Add one only if your config has no otlphttp exporter:

exporters:
  # On Collector v0.144.0 and newer, use "otlp_http" to avoid a deprecation warning.
  otlphttp:
    endpoint: https://ingest.<region>.signoz.cloud:443
    headers:
      signoz-ingestion-key: <your-ingestion-key>

exporters:
  # On Collector v0.144.0 and newer, use "otlp_http" to avoid a deprecation warning.
  otlphttp:
    endpoint: http://<signoz-instance>:4318

Add a resource processor to the processors section. It sets a service name, which gives you one filter for every SNMP metric:

processors:
  resource/snmp:
    attributes:
      - key: service.name
        value: <service-name>
        action: upsert

Verify these values:

• <service-name>: A name that identifies your SNMP devices in SigNoz, for example snmp-devices.

Add a dedicated metrics/snmp pipeline under service.pipelines:

service:
  pipelines:
    metrics/snmp:
      receivers: [snmp]
      processors: [resource/snmp, batch]
      exporters: [otlphttp]

The names in these lists must match the keys you declared. If you renamed the exporter to otlp_http, use that name here too.

The dedicated pipeline leaves out the resourcedetection processor. That processor tags each metric with the Collector host's host.name, which would label firewall metrics with the wrong host.

Set the community string and restart the Collector. On a systemd install from the VM guide, open the Collector's environment file:

sudoedit /etc/otelcol-contrib/otelcol-contrib.conf

Add this line, replacing <community-string> with the device's read-only community string, then restart the service:

SNMP_COMMUNITY=<community-string>

sudo systemctl restart otelcol-contrib

On Docker or Kubernetes, set SNMP_COMMUNITY as an environment variable on the Collector container instead.

Validate

1. In Metrics Explorer, search for snmp.interface.io.
2. Filter by device.name, set the time aggregation to Rate, and group by interface.name and direction. Each interface appears as a receive and a transmit series, in bytes per second.

Metrics collected

Every metric carries the device.name resource attribute, read from the device's sysName, and the service.name you set in Step 3. The cs unit is hundredths of a second. The source OID for each metric is in the comments of the Step 2 config.

Customize the setup

Expand the section that matches your setup.

receivers:
  snmp/fw-01: &snmp_defaults
    endpoint: udp://<device-1-ip>:161
    version: v2c
    community: ${env:SNMP_COMMUNITY}
    collection_interval: 60s
    # resource_attributes, attributes, and metrics from Step 2
 
  snmp/fw-02:
    <<: *snmp_defaults
    endpoint: udp://<device-2-ip>:161
 
service:
  pipelines:
    metrics/snmp:
      receivers: [snmp/fw-01, snmp/fw-02]
      processors: [resource/snmp, batch]
      exporters: [otlphttp]

receivers:
  snmp:
    endpoint: udp://<device-ip>:161
    version: v3
    user: <snmp-user>
    security_level: auth_priv
    auth_type: SHA
    auth_password: ${env:SNMP_AUTH_PASSWORD}
    privacy_type: AES
    privacy_password: ${env:SNMP_PRIVACY_PASSWORD}
    collection_interval: 60s

problem with SNMP GET for OIDs '[.1.3.6.1.2.1.1.3.0]': request timeout (after 0 retries)

Error: invalid configuration: receivers::snmp: metric 'snmp.interface.oper_status' column_oid must either have an indexed resource_attribute or an indexed_value_prefix/oid attribute

problem with getting scalar data: data for OID '.1.3.6.1.4.1.99999.1.0' not found

responded with HTTP Status Code 401, Message=rpc error: code = Unauthenticated desc = Invalid or missing key

Limitations

• The receiver is at alpha stability upstream. Config fields can change between releases.
• The receiver only polls. It does not receive SNMP traps.
• The receiver has no default metrics. You map every OID by hand.
• Device identity comes only from the resource attributes you configure.

Next steps

• Create a metrics-based alert that fires when snmp.interface.oper_status equals 2.
• Create a custom dashboard for interface traffic and errors per device.
• Collect syslog from the same devices to see firewall logs next to their metrics.
• Full receiver config reference: snmp receiver README.
• Collector configuration best practices

Get Help

If you need help with the steps in this topic, please reach out to us on SigNoz Community Slack. If you are a SigNoz Cloud user, please use in product chat support located at the bottom right corner of your SigNoz instance or contact us at cloud-support@signoz.io.