SNMP input plugin

• A component of the snmp integration plugin
• Integration version: v4.0.5
• Released on: 2025-01-06
• Changelog

For other versions, see the Versioned plugin docs.

For questions about the plugin, open a topic in the Discuss forums. For bugs or feature requests, open an issue in Github. For the list of Elastic supported plugins, please consult the Elastic Support Matrix.

The SNMP input polls network devices using Simple Network Management Protocol (SNMP) to gather information related to the current state of the devices operation.

The SNMP input plugin supports SNMP v1, v2c, and v3 over UDP and TCP transport protocols.

Because SNMP data has specific field names based on OIDs, we recommend setting a target. Metadata fields follow a specific naming convention when ECS compatibility mode is enabled.

This plugin already includes the IETF MIBs (management information bases), and you do not need to import them. If you need additional MIBs, you need to import them. Check out Importing MIBs for info.

This plugin supports the following configuration options plus the Common options described later.

This plugin supports the following SNMPv3 authentication options.

Also see Common options for a list of options supported by all input plugins.

• Value type is string

• Supported values are:

  • disabled: does not use ECS-compatible field names (fields might be set at the root of the event)
  • v1, v8: avoids field names that might conflict with Elastic Common Schema (for example, the host field)

• Default value depends on which version of Logstash is running:

  • When Logstash provides a pipeline.ecs_compatibility setting, its value is used as the default
  • Otherwise, the default value is disabled.

Controls this plugin’s compatibility with the Elastic Common Schema (ECS).

• Value type is array
• There is no default value for this setting

Use the get option to query for scalar values for the given OID(s). One or more OID(s) are specified as an array of strings of OID(s).

Example

input {
  snmp {
    get => ["1.3.6.1.2.1.1.1.0", "1.3.6.1.2.1.1.3.0", "1.3.6.1.2.1.1.5.0"]
    hosts => [{host => "udp:127.0.0.1/161" community => "public"}]
  }
}

• Value type is array
• There is no default value for this setting

The hosts option specifies the list of hosts to query the configured get and walk options.

Each host definition is a hash and must define the host key and value. host must use the format {tcp|udp}:{ip address}/{{port}}, for example host => "udp:127.0.0.1/161"

Each host definition can optionally include the following keys and values:

• community the community string, default is public.
• version 1, 2c or 3, default is 2c.
• retries is the number of retries in case of failure, default is 2.
• timeout is the timeout in milliseconds with a default value of 1000.

Specifying all hosts options

input {
  snmp {
    get => ["1.3.6.1.2.1.1.1.0"]
    hosts => [{host => "udp:127.0.0.1/161" community => "public" version => "2c"  retries => 2  timeout => 1000}]
  }
}

Specifying multiple hosts

input {
  snmp {
    get => ["1.3.6.1.2.1.1.1.0"]
    hosts => [{host => "udp:127.0.0.1/161" community => "public"}, {host => "udp:192.168.0.1/161" community => "private"}]
  }
}

Specifying IPv6 hosts

input {
  snmp {
    get => ["1.3.6.1.2.1.1.1.0"]
    hosts => [{host => "udp:[::1]/161" community => "public"}, {host => "udp:[2001:db8::2:1]/161" community => "private"}]
  }
}

• Value type is number
• Default value is 30

The interval option specifies the polling interval in seconds. If polling all configured hosts takes longer than this interval, a warning will be emitted to the logs.

• Value type is string
• There is no default value for this setting

The SNMPv3 local engine ID. Its length must be greater or equal than 5 and less or equal than 32. If not provided, a default ID is generated based on the local IP address and additional four random bytes.

• Value type is path
• There is no default value for this setting

The mib_paths option specifies the location of one or more imported MIB files. The value can be either a dir path containing the imported MIB (.dic, .yaml) files, or a file path to a single MIB file.

This plugin includes the IETF MIBs. If you require other MIBs, you need to import them. See Importing MIBs.

• Value can be any of: default, ruby_snmp, dotted_string
• Default value is "default"

Defines the mapping textual representation of an OID in the Logstash event:

• default translates every identifier, using the MIBs resolved names, separated by dots. Example: 1.3.6.1.2.1.1.2.0 is mapped as iso.org.dod.internet.mgmt.mib-2.system.sysObjectID.0
• ruby_snmp produces field names prefixed by the MIBs module name, followed by the latest resolved identifier name and unknowns values. Example: 1.3.6.1.2.1.1.2.0 is mapped as SNMPv2-MIB::sysObjectID.0.
• dotted_string maps fields using the standard dotted string representation, Example: 1.3.6.1.2.1.1.2.0 is mapped as 1.3.6.1.2.1.1.2.0

• Value type is boolean
• Default value is false

Defines if the Logstash event fields values, which types are OID, are mapped using the configured OID textual representation set on the oid_mapping_format option.

• Value type is number
• Default value is 0

The oid_root_skip option specifies the number of OID root digits to ignore in the event field name. For example, in a numeric OID like "1.3.6.1.2.1.1.1.0" the first 5 digits could be ignored by setting oid_root_skip => 5 which would result in a field name "1.1.1.0". Similarly when a MIB is used an OID such "1.3.6.1.2.mib-2.system.sysDescr.0" would become "mib-2.system.sysDescr.0"

• You can use this setting or oid_path_length, but not both at the same time.
• Use this setting only if oid_mapping_format is set to default.

• Value type is number
• Default value is 0

The oid_path_length option specifies the number of OID root digits to retain in the event field name. For example, in a numeric OID like "1.3.6.1.2.1.1.1.0" the last 2 digits could be retained by setting oid_path_length => 2 which would result in a field name "1.0". Similarly when a MIB is used an OID such "1.3.6.1.2.mib-2.system.sysDescr.0" would become "sysDescr.0"

• You can use this setting or oid_root_skip, but not both at the same time.
• This setting can be used only if oid_mapping_format is set to default.

• Value type is number
• There is no default value for this setting

Specifies the maximum amount of time in milliseconds the polling client will wait for all hosts responses. If all responses are not received before the timeout elapses, the client will fail and some hosts might not get polled during the current cycle.

By default, it uses the highest value between 1 hour, the maximum hosts configured timeout, and the interval value.

• Value type is array
• There is no default value for this setting

Use the walk option to retrieve the subtree of information for the given OID(s). One or more OID(s) are specified as an array of strings of OID(s).

Queries the subtree of information starting at the given OID(s).

Example

  snmp {
    walk => ["1.3.6.1.2.1.1"]
    hosts => [{host => "udp:127.0.0.1/161" community => "public"}]
  }
}

• Value type is array
• There is no default value for this setting
• Results are returned under a field using the table name

The tables option is used to query for tabular values for the given column OID(s).

Each table definition is a hash and must define the name key and value and the columns to return.

Specifying a single table

input {
  snmp {
    hosts => [{host => "udp:127.0.0.1/161" community => "public" version => "2c"  retries => 2  timeout => 1000}]
    tables => [ {"name" => "interfaces" "columns" => ["1.3.6.1.2.1.2.2.1.1", "1.3.6.1.2.1.2.2.1.2", "1.3.6.1.2.1.2.2.1.5"]} ]
  }
}

Specifying multiple tables

input {
  snmp {
    get => ["1.3.6.1.2.1.1.1.0"]
    tables => [ {"name" => "interfaces" "columns" => ["1.3.6.1.2.1.2.2.1.1", "1.3.6.1.2.1.2.2.1.2", "1.3.6.1.2.1.2.2.1.5"]}, {"name" => "ltmPoolStatTable" "columns" => ["1.3.6.1.4.1.3375.2.2.5.2.3.1.1", "1.3.6.1.4.1.3375.2.2.5.2.3.1.6"]} ]
  }
}

• Value type is string
• There is no default value for this setting

The name of the field under which SNMP payloads are assigned. If not specified data will be stored in the root of the event.

Setting a target is recommended when ecs_compatibility is enabled.

• Value type is number
• Default value is the number of CPU cores

The number of threads to use for executing the hosts SNMP requests.

• Value type is boolean
• Default value is true

This plugin provides all IETF MIBs (management information bases), publicly available in the libsmi version 0.5.0. When enabled, it automatically loads the bundled MIBs and provides mapping of the numeric OIDs to MIB field names in the resulting event.

A single user can be configured and will be used for all defined SNMPv3 hosts. Multiple snmp input declarations will be needed if multiple SNMPv3 users are required. These options are required only if you are using SNMPv3.

• Value type is password
• There is no default value for this setting

The auth_pass option specifies the SNMPv3 authentication passphrase or password.

The auth_protocol option specifies the SNMPv3 authentication protocol or type

• Value can be any of: md5, sha, sha2, hmac128sha224, hmac192sha256, hmac256sha384, hmac384sha512
• Note that sha2 and hmac192sha256 are equivalent
• There is no default value for this setting

• Value type is password
• There is no default value for this setting

The priv_pass option specifies the SNMPv3 encryption password.

• Value can be any of: des, 3des, aes, aes128, aes192, aes256
• Note that aes and aes128 are equivalent
• There is no default value for this setting

The priv_protocol option specifies the SNMPv3 privacy/encryption protocol.

• Value can be any of: noAuthNoPriv, authNoPriv, authPriv
• There is no default value for this setting

The security_level option specifies the SNMPv3 security level between Authentication, No Privacy; Authentication, Privacy; or no Authentication, no Privacy.

• Value type is string
• There is no default value for this setting

The security_name option specifies the SNMPv3 security name or user name.

Specifying SNMPv3 settings

input {
  snmp {
    hosts => [{host => "udp:127.0.0.1/161" version => "3"}]
    get => ["1.3.6.1.2.1.1.1.0"]
    security_name => "mySecurityName"
    auth_protocol => "sha"
    auth_pass => "ShaPassword"
    priv_protocol => "aes"
    priv_pass => "AesPasword"
    security_level => "authPriv"
  }
}

Using both get and walk in the same poll cycle for each host(s)

input {
  snmp {
    get => ["1.3.6.1.2.1.1.1.0", "1.3.6.1.2.1.1.3.0", "1.3.6.1.2.1.1.5.0"]
    walk => ["1.3.6.1.2.1.1"]
    hosts => [{host => "udp:127.0.0.1/161" community => "public"}]
  }
}

Specifying all global options

input {
  snmp {
    get => ["1.3.6.1.2.1.1.1.0"]
    hosts => [{host => "udp:127.0.0.1/161"}]

    mib_paths => ["path/to/converted/mibfile.dic"]
    oid_root_skip => 0
    interval => 30
  }
}

All the polled host information is stored in the event @metadata:

• [@metadata][host_protocol] : udp or tcp
• [@metadata][host_address] : host address for example 127.0.0.1
• [@metadata][host_port] : host port (for example 161)
• [@metadata][host_community] : community string for example public

By default, a host field is added to the event with the [@metadata][host_address] value.

config :add_field, :validate => :hash, :default => { "host" => "%{[@metadata][host_address]}" }

You can customize the format and content of the host field by specifying an alternate add_field.

Example

input {
  snmp {
    get => ["1.3.6.1.2.1.1.1.0"]
    hosts => [{host => "udp:127.0.0.1/161"}]

    add_field => {host => "%{[@metadata][host_protocol]}:%{[@metadata][host_address]}/%{[@metadata][host_port]},%{[@metadata][host_community]}"}
  }
}

These configuration options are supported by all input plugins:

• Value type is hash
• Default value is {}

Add a field to an event

• Value type is boolean
• Default value is true

Disable or enable metric logging for this specific plugin instance by default we record all the metrics we can, but you can disable metrics collection for a specific plugin.

• Value type is string
• There is no default value for this setting.

Add a unique ID to the plugin configuration. If no ID is specified, Logstash will generate one. It is strongly recommended to set this ID in your configuration. This is particularly useful when you have two or more plugins of the same type, for example, if you have 2 snmp inputs. Adding a named ID in this case will help in monitoring Logstash when using the monitoring APIs.

input {
  snmp {
    id => "my_plugin_id"
  }
}

• Value type is array
• There is no default value for this setting.

Add any number of arbitrary tags to your event.

This can help with processing later.

• Value type is string
• There is no default value for this setting.

Add a type field to all events handled by this input.

Types are used mainly for filter activation.

The type is stored as part of the event itself, so you can also use the type to search for it in Kibana.

If you try to set a type on an event that already has one (for example when you send an event from a shipper to an indexer) then a new input will not override the existing type. A type set at the shipper stays with that event for its life even when sent to another Logstash server.