SNMP devices

Plugin: go.d.plugin Module: snmp

Overview

This SNMP collector discovers and gathers statistics for network interfaces on SNMP-enabled devices:

• Traffic
• Packets (unicast, multicast, broadcast)
• Errors
• Discards
• Administrative and operational status

Additionally, it collects overall device uptime.

It is compatible with all SNMP versions (v1, v2c, and v3) and uses the gosnmp package.

For advanced users:

• You can manually specify custom OIDs (Object Identifiers) to retrieve specific data points beyond the default metrics.
• However, defining custom charts with dimensions for these OIDs requires manual configuration.

This collector is supported on all platforms.

This collector supports collecting metrics from multiple instances of this integration, including remote instances.

Default Behavior

Auto-Detection

SNMP service discovery is a dedicated component that automatically scans configured networks to find SNMP-enabled devices.

• This feature is disabled by default and requires explicit user configuration to activate.
• When enabled, it discovers devices using customizable credentials, supports various IP range formats (single IPs, ranges, CIDR) with a limit of 512 IPs per subnet, and optimizes network traffic through configurable caching of discovery results.
• Discovered devices are automatically made available to the SNMP collector for monitoring.

The configuration file name is go.d/sd/snmp.conf.

You can edit the configuration file using the edit-config script from the Netdata config directory.

 cd /etc/netdata 2>/dev/null || cd /opt/netdata/etc/netdata
 sudo ./edit-config go.d/sd/snmp.conf

Limits

The default configuration for this integration does not impose any limits on data collection.

Performance Impact

Device limitations: Many SNMP switches and routers have limited processing power. They might not be able to report data as frequently as desired. You can monitor response times using go.d.plugin in debug mode to identify potential bottlenecks.

Concurrent access: If multiple collectors or tools access the same SNMP device simultaneously, data points might be skipped. This is a limitation of the device itself, not this collector. To mitigate this, consider increasing the collection interval (update_every) to reduce the frequency of requests.

Metrics

Metrics grouped by scope.

The scope defines the instance that the metric belongs to. An instance is uniquely identified by a set of labels.

The metrics that will be collected are defined in the configuration file.

Per snmp device

These metrics refer to the SNMP device.

Labels:

Label	Description
sysName	SNMP device's system name (OID: 1.3.6.1.2.1.1.5).

Metrics:

Metric	Dimensions	Unit
snmp.device_uptime	uptime	seconds

Per network interface

Network interfaces of the SNMP device being monitored. These metrics refer to each interface.

Labels:

Label	Description
sysName	SNMP device's system name (OID: 1.3.6.1.2.1.1.5).
ifDescr	Network interface description (OID: 1.3.6.1.2.1.2.2.1.2).
ifName	Network interface name (OID: 1.3.6.1.2.1.2.2.1.2).
ifType	Network interface type (OID: 1.3.6.1.2.1.2.2.1.2).

Metrics:

Metric	Dimensions	Unit
snmp.device_net_interface_traffic	received, sent	kilobits/s
snmp.device_net_interface_unicast	received, sent	packets/s
snmp.device_net_interface_multicast	received, sent	packets/s
snmp.device_net_interface_broadcast	received, sent	packets/s
snmp.device_net_interface_errors	inbound, outbound	errors/s
snmp.device_net_interface_discards	inbound, outbound	discards/s
snmp.device_net_interface_admin_status	up, down, testing	status
snmp.device_net_interface_oper_status	up, down, testing, unknown, dormant, not_present, lower_layer_down	status

Alerts

There are no alerts configured by default for this integration.

Setup

Prerequisites

No action required.

Configuration

File

The configuration file name for this integration is go.d/snmp.conf.

The file format is YAML. Generally, the structure is:

update_every: 1
autodetection_retry: 0
jobs:
  - name: some_name1
  - name: some_name1

You can edit the configuration file using the edit-config script from the Netdata config directory.

cd /etc/netdata 2>/dev/null || cd /opt/netdata/etc/netdata
sudo ./edit-config go.d/snmp.conf

Options

The following options can be defined globally: update_every, autodetection_retry.

Config options

Name	Description	Default	Required
update_every	Data collection frequency.	10	no
autodetection_retry	Recheck interval in seconds. Zero means no recheck will be scheduled.	0	no
hostname	Target ipv4 address.		yes
create_vnode	If set, the collector will create a Netdata Virtual Node for this SNMP device, which will appear as a separate Node in Netdata.	true	no
vnode.guid	A unique identifier for the Virtual Node. If not set, a GUID will be automatically generated from the device's IP address.		no
vnode.hostname	The hostname that will be used for the Virtual Node. If not set, the device's hostname will be used.		no
vnode.labels	Additional key-value pairs to associate with the Virtual Node.		no
community	SNMPv1/2 community string.	public	no
options.version	SNMP version. Available versions: 1, 2, 3.	2	no
options.port	Target port.	161	no
options.retries	Retries to attempt.	1	no
options.timeout	SNMP request/response timeout.	5	no
options.max_repetitions	Controls how many SNMP variables to retrieve in a single GETBULK request.	25	no
options.max_request_size	Maximum number of OIDs allowed in a single GET request.	60	no
network_interface_filter.by_name	Filter interfaces by their names using simple patterns.		no
network_interface_filter.by_type	Filter interfaces by their types using simple patterns.		no
user.name	SNMPv3 user name.		no
user.name	Security level of SNMPv3 messages.		no
user.auth_proto	Security level of SNMPv3 messages.		no
user.name	Authentication protocol for SNMPv3 messages.		no
user.auth_key	Authentication protocol pass phrase.		no
user.priv_proto	Privacy protocol for SNMPv3 messages.		no
user.priv_key	Privacy protocol pass phrase.		no
charts	List of charts.	[]	yes
charts.id	Chart ID. Used to uniquely identify the chart.		yes
charts.title	Chart title.	Untitled chart	no
charts.units	Chart units.	num	no
charts.family	Chart family.	charts.id	no
charts.type	Chart type (line, area, stacked).	line	no
charts.priority	Chart priority.	70000	no
charts.multiply_range	Used when you need to define many charts using incremental OIDs.	[]	no
charts.dimensions	List of chart dimensions.	[]	yes
charts.dimensions.oid	Collected metric OID.		yes
charts.dimensions.name	Dimension name.		yes
charts.dimensions.algorithm	Dimension algorithm (absolute, incremental).	absolute	no
charts.dimensions.multiplier	Collected value multiplier, applied to convert it properly to units.	1	no
charts.dimensions.divisor	Collected value divisor, applied to convert it properly to units.	1	no

user.auth_proto

The security of an SNMPv3 message as per RFC 3414 (user.level):

String value	Int value	Description
none	1	no message authentication or encryption
authNoPriv	2	message authentication and no encryption
authPriv	3	message authentication and encryption

user.name

The digest algorithm for SNMPv3 messages that require authentication (user.auth_proto):

String value	Int value	Description
none	1	no message authentication
md5	2	MD5 message authentication (HMAC-MD5-96)
sha	3	SHA message authentication (HMAC-SHA-96)
sha224	4	SHA message authentication (HMAC-SHA-224)
sha256	5	SHA message authentication (HMAC-SHA-256)
sha384	6	SHA message authentication (HMAC-SHA-384)
sha512	7	SHA message authentication (HMAC-SHA-512)

user.priv_proto

The encryption algorithm for SNMPv3 messages that require privacy (user.priv_proto):

String value	Int value	Description
none	1	no message encryption
des	2	ES encryption (CBC-DES)
aes	3	128-bit AES encryption (CFB-AES-128)
aes192	4	192-bit AES encryption (CFB-AES-192) with "Blumenthal" key localization
aes256	5	256-bit AES encryption (CFB-AES-256) with "Blumenthal" key localization
aes192c	6	192-bit AES encryption (CFB-AES-192) with "Reeder" key localization
aes256c	7	256-bit AES encryption (CFB-AES-256) with "Reeder" key localization

Examples

SNMPv1/2

In this example:

• the SNMP device is 192.0.2.1.
• the SNMP version is 2.
• the SNMP community is public.
• we will update the values every 10 seconds.

Config

jobs:
  - name: switch
    update_every: 10
    hostname: 192.0.2.1
    community: public
    options:
      version: 2

SNMPv3

To use SNMPv3:

• use user instead of community.
• set options.version to 3.

Config

jobs:
  - name: switch
    update_every: 10
    hostname: 192.0.2.1
    options:
      version: 3
    user:
      name: username
      level: authPriv
      auth_proto: sha256
      auth_key: auth_protocol_passphrase
      priv_proto: aes256
      priv_key: priv_protocol_passphrase

Custom OIDs

In this example:

• the SNMP device is 192.0.2.1.
• the SNMP version is 2.
• the SNMP community is public.
• we will update the values every 10 seconds.

Config

jobs:
  - name: switch
    update_every: 10
    hostname: 192.0.2.1
    community: public
    options:
      version: 2
    charts:
      - id: "bandwidth_port1"
        title: "Switch Bandwidth for port 1"
        units: "kilobits/s"
        type: "area"
        family: "ports"
        dimensions:
          - name: "in"
            oid: "1.3.6.1.2.1.2.2.1.10.1"
            algorithm: "incremental"
            multiplier: 8
            divisor: 1000
          - name: "out"
            oid: "1.3.6.1.2.1.2.2.1.16.1"
            multiplier: -8
            divisor: 1000
      - id: "bandwidth_port2"
        title: "Switch Bandwidth for port 2"
        units: "kilobits/s"
        type: "area"
        family: "ports"
        dimensions:
          - name: "in"
            oid: "1.3.6.1.2.1.2.2.1.10.2"
            algorithm: "incremental"
            multiplier: 8
            divisor: 1000
          - name: "out"
            oid: "1.3.6.1.2.1.2.2.1.16.2"
            multiplier: -8
            divisor: 1000

Custom OIDs with multiply range

If you need to define many charts using incremental OIDs, you can use the charts.multiply_range option.

This is like the SNMPv1/2 example, but the option will multiply the current chart from 1 to 24 inclusive, producing 24 charts in total for the 24 ports of the switch 192.0.2.1.

Each of the 24 new charts will have its id (1-24) appended at:

• its chart unique id, i.e. bandwidth_port_1 to bandwidth_port_24.
• its title, i.e. Switch Bandwidth for port 1 to Switch Bandwidth for port 24.
• its oid (for all dimensions), i.e. dimension in will be 1.3.6.1.2.1.2.2.1.10.1 to 1.3.6.1.2.1.2.2.1.10.24.
• its priority will be incremented for each chart so that the charts will appear on the dashboard in this order.

Config

jobs:
  - name: switch
    update_every: 10
    hostname: "192.0.2.1"
    community: public
    options:
      version: 2
    charts:
      - id: "bandwidth_port"
        title: "Switch Bandwidth for port"
        units: "kilobits/s"
        type: "area"
        family: "ports"
        multiply_range: [1, 24]
        dimensions:
          - name: "in"
            oid: "1.3.6.1.2.1.2.2.1.10"
            algorithm: "incremental"
            multiplier: 8
            divisor: 1000
          - name: "out"
            oid: "1.3.6.1.2.1.2.2.1.16"
            multiplier: -8
            divisor: 1000

Multiple devices with a common configuration

YAML supports anchors. The & defines and names an anchor, and the * uses it. <<: *anchor means, inject the anchor, then extend. We can use anchors to share the common configuration for multiple devices.

The following example:

• adds an anchor to the first job.
• injects (copies) the first job configuration to the second and updates name and hostname parameters.
• injects (copies) the first job configuration to the third and updates name and hostname parameters.

Config

jobs:
  - &anchor
    name: switch
    update_every: 10
    hostname: "192.0.2.1"
    community: public
    options:
      version: 2
    charts:
      - id: "bandwidth_port1"
        title: "Switch Bandwidth for port 1"
        units: "kilobits/s"
        type: "area"
        family: "ports"
        dimensions:
          - name: "in"
            oid: "1.3.6.1.2.1.2.2.1.10.1"
            algorithm: "incremental"
            multiplier: 8
            divisor: 1000
          - name: "out"
            oid: "1.3.6.1.2.1.2.2.1.16.1"
            multiplier: -8
            divisor: 1000
  - <<: *anchor
    name: switch2
    hostname: "192.0.2.2"
  - <<: *anchor
    name: switch3
    hostname: "192.0.2.3"

Troubleshooting

Debug Mode

Important: Debug mode is not supported for data collection jobs created via the UI using the Dyncfg feature.

To troubleshoot issues with the snmp collector, run the go.d.plugin with the debug option enabled. The output should give you clues as to why the collector isn't working.

• Navigate to the plugins.d directory, usually at /usr/libexec/netdata/plugins.d/. If that's not the case on your system, open netdata.conf and look for the plugins setting under [directories].

  cd /usr/libexec/netdata/plugins.d/

• Switch to the netdata user.

  sudo -u netdata -s

• Run the go.d.plugin to debug the collector:

  ./go.d.plugin -d -m snmp

Getting Logs

If you're encountering problems with the snmp collector, follow these steps to retrieve logs and identify potential issues:

• Run the command specific to your system (systemd, non-systemd, or Docker container).
• Examine the output for any warnings or error messages that might indicate issues. These messages should provide clues about the root cause of the problem.

System with systemd

Use the following command to view logs generated since the last Netdata service restart:

journalctl _SYSTEMD_INVOCATION_ID="$(systemctl show --value --property=InvocationID netdata)" --namespace=netdata --grep snmp

System without systemd

Locate the collector log file, typically at /var/log/netdata/collector.log, and use grep to filter for collector's name:

grep snmp /var/log/netdata/collector.log

Note: This method shows logs from all restarts. Focus on the latest entries for troubleshooting current issues.

Docker Container

If your Netdata runs in a Docker container named "netdata" (replace if different), use this command:

docker logs netdata 2>&1 | grep snmp