SNMP devices

Plugin: go.d.plugin Module: snmp

Overview

This collector monitors any SNMP devices and uses the gosnmp package.

It supports:

• all SNMP versions: SNMPv1, SNMPv2c and SNMPv3.
• any number of SNMP devices.
• each SNMP device can be used to collect data for any number of charts.
• each chart may have any number of dimensions.
• each SNMP device may have a different update frequency.
• each SNMP device will accept one or more batches to report values (you can set max_request_size per SNMP server, to control the size of batches).

Keep in mind that many SNMP switches and routers are very slow. They may not be able to report values per second. go.d.plugin reports the time it took for the SNMP device to respond when executed in the debug mode.

Also, if many SNMP clients are used on the same SNMP device at the same time, values may be skipped. This is a problem of the SNMP device, not this collector. In this case, consider reducing the frequency of data collection (increasing update_every).

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

This integration doesn't support auto-detection.

Limits

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

Performance Impact

The default configuration for this integration is not expected to impose a significant performance impact on the system.

Metrics

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

Alerts

There are no alerts configured by default for this integration.

Setup

Prerequisites

Find OIDs

Use snmpwalk, like this:

snmpwalk -t 20 -O fn -v 2c -c public 192.0.2.1

• -t 20 is the timeout in seconds.
• -O fn will display full OIDs in numeric format.
• -v 2c is the SNMP version.
• -c public is the SNMP community.
• 192.0.2.1 is the SNMP device.

Configuration

File

The configuration file name for this integration is go.d/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/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.	1	no
autodetection_retry	Recheck interval in seconds. Zero means no recheck will be scheduled.	0	no
hostname	Target ipv4 address.	127.0.0.1	yes
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.	10	no
options.max_request_size	Maximum number of OIDs allowed in one one SNMP request.	60	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.
• we define 2 charts bandwidth_port1 and bandwidth_port2, each having 2 dimensions: in and out.

SNMPv1: just set options.version to 1. Note: the algorithm chosen is incremental, because the collected values show the total number of bytes transferred, which we need to transform into kbps. To chart gauges (e.g. temperature), use absolute instead.

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

SNMPv3

To use SNMPv3:

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

The rest of the configuration is the same as in the SNMPv1/2 example.

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

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

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