SNMP probe parameters

This list of parameters may be passed to the SNMP probe.

For instructions on configuring probe parameters, see Set probe parameters.

Parameter Description Default Value
oid_spec_list

A list of OID specifications, one per line. Each specification must be in one of the following two forms:

  • walk {OID}: walks the OID and all its children
  • table {OID} {OID Children}: walks all entries in the table, returning only the given children (e.g., "iso.org.dod.internet")

{OID Children} refers to a comma-delimited list of child nodes within the entries for the given table. For example, "ifEntry.ifIndex,ifEntry.ifDescr,ifEntry.ifType" are OID children of the table "iso.org.dod.internet.mgmt.mib-2.interfaces.ifTable". As a convenience, the table entry prefix may be left off. (The preceding children could be specified as "ifIndex,ifDescr,ifType".)

Any child may include a filter qualifier in parentheses. For example, the child "entPhysicalContainedIn(=0)" specifies returning table entries only if the value of "entPhysicalContainedIn" equals 0. The operators supported in the expression are:
= equals
!= does not equal
# contains

If more than one child has a filter expression, a match on any one of the children causes that entry to be read.

Any content including and after a "//" is ignored (comments). Any OID that doesn't start with "1.3.6.1" or "iso.org.dod.internet" will automatically be prefaced with "1.3.6.1." as a convenience.

required
source The IP address or host name of the device to query SNMP on. required
index The index to apply after the community string, for Cisco-style community string indexing (for VLAN interrogation). 0
credential_id The sys_id of a specific credential that is preferred for use above the rest. 1 none
credential_tag The credential tag that must be used. 2 none
timeout

The timeout value (in milliseconds) to wait for a response, instead of the default.

Note: When use_getbulk is set to true, the timeout value is for an individual GETBULK request.
1500
established_session_timeout The interval (in milliseconds) to wait for a response after at least one response has been received. Longer values can be useful for collecting more complete and accurate data. 500
debug Enables debug logging. Set to true for debug mode. false
request_interval The interval (in milliseconds) between successive requests for an OID when a response has not been received. If this value is smaller than the timeout value (or established session timeout value), then multiple requests will be sent if a device takes too long to respond. The default value is 250ms, or 0.25 seconds. For example, suppose a device takes 0.9 seconds to respond to a query. Queries will be sent, four in all, at t + 0, t + 250ms, t + 500ms, and t + 750ms. The device may respond with between 1 and 4 responses. If this value is set to at least as long as the timeout value, then only a single request will ever be sent for any particular OID. 400
request_delay The interval (in milliseconds) between the receipt of a response and the transmission of the next request. The default is 0 (no delay). This value may be set to slow the overall rate of an SNMP query. 0
result_format Returns JSON formatted payloads for the SNMP - F5 BIG-IP - System and SNMP - Netscaler - System probes. This parameter returns data in a more compact format to prevent sensor failure or memory problems on a node when the payload becomes very large. Do not change this value or delete this parameter. This parameter is available for releases at Istanbul Patch 6 and later.
Caution: Use of this parameter with any other probes will cause the sensor to fail.
JSON
use_getbulk

Enables the use of SNMP GETBULK requests to retrieve tabular data from SNMP devices instead of using multiple SNMP GETNEXT requests. For tabular data, GETBULK is more efficient. Regardless of the request type, certain devices may not return any results if they are busy with other tasks.

The established_session_timeout, request_interval, and request_delay parameters are ignored when use_getbulk is set to true. Instead, the retries parameter is available. This is the same timeout configuration used by use_getscalar.

Note: SNMP GETBULK is only available on devices that support SNMPv2c or SNMPv3. Requests to devices configured to use SNMPv1 only, automatically revert to using GETNEXT with no further configuration required.
By default, the following probes use GETBULK requests (the parameter value is true).
  • SNMP - Switch - Vlan
  • SNMP - Switch - BridgePortTable
  • SNMP - Switch - ForwardingTable
  • SNMP - Switch - SpanningTreeTable
  • SNMP - Network - ArpTable
  • SNMP - Layer 2 Protocol Caches
  • SNMP - F5 BIG IP - System (only for Service Mapping customers)
Note: These probes have a timeout value of 5000.
false
use_getscalar Enables the use of simplified retrieval and handling of scalar values from SNMP devices.

The established_session_timeout, request_interval, and request_delay parameters are ignored when use_getscalar is set to true. Instead, the retries and timeout parameters are available. This is the same timeout configuration used by use_getbulk.

false
retries The number of additional attempts Discovery makes to complete an individual GETBULK request (see use_getbulk) or a GETNEXT request when the use_getscalar parameter is set to true. 2
1 This parameter is for internal use only and is not supported.
2 This parameter is for internal use only and is not supported.