Optional OS Settings

This page describes the settings of the OS YAML files and of config.php. All these settings are optional. Without a setting, LibreNMS uses the global default.

User override in config.php

A user can override these settings in config.php.

For example, this line sets a different icon for ios:

$config['os']['ios']['icon'] = 'fuzzybunny';

Ignoring Sensors

The configuration can filter out some sensors:

Filter all 'current' sensors for Operating System 'vrp'.

$config['os']['vrp']['disabled_sensors']['current'] = true;

Filter all sensors with description matching regexp '/PEM Iout/' for Operating System iosxe.

$config['os']['iosxe']['disabled_sensors_regex'][] = '/PEM Iout/';

Filter all 'power' sensors with description matching regexp '/ Power [TR]x /' for Operating System iosxr.

$config['os']['iosxr']['disabled_sensors_regex']['power'][] = '/ Power [TR]x /';

Ignore all temperature sensors

$config['disabled_sensors']['temperature'] = true;

Filter all sensors matching with description regexp '/PEM Iout/'.

$config['disabled_sensors_regex'][] = '/PEM Iout/';

Ignoring Interfaces

LibreNMS combines these settings with the global settings. Only good_if cancels a global setting.

empty_ifdescr: false # allow empty ifDescr
bad_if: # ifDescr (substring, case insensitive)
    - lp0
bad_if_regexp: # ifDescr (regex, case insensitive)
    - "/^ng[0-9]+$/"
bad_ifname_regexp: # ifName (regex, case insensitive)
    - "/^xdsl_channel /"
bad_ifalias_regexp: # ifAlias (regex, case insensitive)
    - "/^vlan/"
bad_iftype: # ifType (substring)
    - sonet
good_if: # ignore all other bad_if settings ifDescr (substring, case insensitive)
    - virtual
bad_ifoperstatus # IfOperStatus (substring, case insensitive)
    - notPresent

Controlling interface labels

By default, LibreNMS uses ifDescr as the label of a port. ifname and ifalias override this default. Set only one of the two. The user supplies ifAlias. ifindex adds the ifIndex to the end of the port label.

ifname: true
ifalias: true

ifindex: true

Poller and Discovery Modules

You can enable and disable each discovery module and poller module for one OS. The defaults are usually correct, so few changes are necessary. You can enable and disable a module for one device in the web interface. You can also do this for one OS or globally in config.php. A poller module usually needs its discovery module.

Do not set these values to false in an OS definition, unless the module makes the polling much worse. A module in the definition reduces the control of the user.

poller_modules:
    bgp-peers: true
discovery_modules:
    arp-table: false

SNMP Settings

Disable snmpbulkwalk

Some devices have a bad SNMP implementation. They answer the faster snmpbulkwalk poorly. This setting disables snmpbulkwalk. LibreNMS then uses only snmpwalk for that OS.

snmp_bulk: false

If only some OIDs fail with snmpbulkwalk, disable those OIDs. The value must match the OID of the LibreNMS walk exactly. We prefer the MIB::oid form, because it prevents a name collision.

oids:
    no_bulk:
        - UCD-SNMP-MIB::laLoadInt

Limit the oids per snmpget

snmp_max_oid: 8

Define SNMP repeater value by OS

Example ios:

lnms config:set ios.snmp.max_repeaters: 30