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Microsoft DHCP SNMP

Pack assets​

Templates​

The Monitoring Connector Microsoft DHCP SNMP brings a host template:

  • App-Microsoft-Dhcp-SNMP-custom

The connector brings the following service templates (sorted by the host template they are attached to):

Service AliasService TemplateService DescriptionDiscovery
SubnetsApp-Microsoft-Dhcp-Subnets-SNMP-customCheck subnetsX

The services listed above are created automatically when the App-Microsoft-Dhcp-SNMP-custom host template is used.

If Discovery is checked, it means a service discovery rule exists for this service template.

Discovery rules​

Host discovery​

Rule nameDescription
SNMP AgentsDiscover your resources through an SNMP subnet scan. You need to install the Generic SNMP connector to get the discovery rule and create a template mapper for the App-Microsoft-Dhcp-SNMP-custom host template

More information about discovering hosts automatically is available on the dedicated page.

Service discovery​

Rule nameDescription
App-Microsoft-Dhcp-SNMP-SubnetsDiscovery of DHCP Subnets

More information about discovering services automatically is available on the dedicated page and in the following chapter.

Collected metrics & status​

Here is the list of services for this connector, detailing all metrics linked to each service.

Metric nameUnit
subnets#statusN/A
subnets#subnet.addresses.usage.countcount
subnets#subnet.addresses.free.countcount
subnets#subnet.addresses.usage.percentage%
subnets#subnet.pending.offers.countcount

Prerequisites​

SNMP Configuration​

The SNMP service must be configured and activated on the host. Please refer to the official documentation from the constructor/editor.

Network flow​

The target resource must be reachable from the Centreon poller on the UDP/161 SNMP port.

Installing the monitoring connector​

Pack​

The installation procedures for monitoring connectors are slightly different depending on whether your license is offline or online.

  1. If the platform uses an online license, you can skip the package installation instruction below as it is not required to have the connector displayed within the Configuration > Connectors > Monitoring Connectors menu. If the platform uses an offline license, install the package on the central server with the command corresponding to the operating system's package manager:
dnf install centreon-pack-applications-microsoft-dhcp-snmp
  1. Whatever the license type (online or offline), install the Microsoft DHCP SNMP connector through the Configuration > Connectors > Monitoring Connectors menu.

Plugin​

Since Centreon 22.04, you can benefit from the 'Automatic plugin installation' feature. When this feature is enabled, you can skip the installation part below.

You still have to manually install the plugin on the poller(s) when:

  • Automatic plugin installation is turned off
  • You want to run a discovery job from a poller that doesn't monitor any resource of this kind yet

More information in the Installing the plugin section.

Use the commands below according to your operating system's package manager:

dnf install centreon-plugin-Applications-Microsoft-Dhcp-Snmp

Using the monitoring connector​

Using a host template provided by the connector​

  1. Log into Centreon and add a new host through Configuration > Hosts.
  2. Fill in the Name, Alias & IP Address/DNS fields according to your resource's settings.
  3. Apply the App-Microsoft-Dhcp-SNMP-custom template to the host.

When using SNMP v3, use the SNMPEXTRAOPTIONS macro to add specific authentication parameters. More information in the Troubleshooting SNMP section.

MacroDescriptionDefault valueMandatory
SNMPEXTRAOPTIONSAny extra option you may want to add to every command (a --verbose flag for example). All options are listed here.
  1. Deploy the configuration. The host appears in the list of hosts, and on the Resources Status page. The command that is sent by the connector is displayed in the details panel of the host: it shows the values of the macros.

Using a service template provided by the connector​

  1. If you have used a host template and checked Create Services linked to the Template too, the services linked to the template have been created automatically, using the corresponding service templates. Otherwise, create manually the services you want and apply a service template to them.
  2. Fill in the macros you want (e.g. to change the thresholds for the alerts). Some macros are mandatory (see the table below).
MacroDescriptionDefault valueMandatory
FILTERSUBNETADDRESSFilter subnets by address (can be a regexp)
WARNINGADDRESSESUSAGEThresholds
CRITICALADDRESSESUSAGEThresholds
WARNINGADDRESSESUSAGEFREEThresholds
CRITICALADDRESSESUSAGEFREEThresholds
WARNINGADDRESSESUSAGEPRCTThresholds
CRITICALADDRESSESUSAGEPRCTThresholds
WARNINGPENDINGOFFERSThresholds
CRITICALPENDINGOFFERSThresholds
EXTRAOPTIONSAny extra option you may want to add to the command (a --verbose flag for example). All options are listed here.--verbose
  1. Deploy the configuration. The service appears in the list of services, and on the Resources Status page. The command that is sent by the connector is displayed in the details panel of the service: it shows the values of the macros.

How to check in the CLI that the configuration is OK and what are the main options for?​

Once the plugin is installed, log into your Centreon poller's CLI using the centreon-engine user account (su - centreon-engine). Test that the connector is able to monitor a resource using a command like this one (replace the sample values by yours):

/usr/lib/centreon/plugins/centreon_microsoft_dhcp_snmp.pl \
	--plugin=apps::microsoft::dhcp::snmp::plugin \
	--mode=subnets \
	--hostname='10.0.0.1' \
	--snmp-version='2c' \
	--snmp-community='my-snmp-community'  \
	--filter-subnet-address='' \
	--warning-addresses-usage='' \
	--critical-addresses-usage='' \
	--warning-addresses-usage-free='' \
	--critical-addresses-usage-free='' \
	--warning-addresses-usage-prct='' \
	--critical-addresses-usage-prct='' \
	--warning-pending-offers='' \
	--critical-pending-offers='' \
	--verbose

The expected command output is shown below:

OK: All subnets are ok | '*subnets*#subnet.addresses.usage.count'=36;;0;50; '*subnets*#subnet.addresses.free.count'=15;;0;50; '*subnets*#subnet.addresses.usage.percentage'=70.00%;0:80;0:90;0;100 '*subnets*#subnet.pending.offers.count'=0;;;0;

Troubleshooting​

Please find the troubleshooting documentation for Centreon Plugins typical issues.

Available modes​

In most cases, a mode corresponds to a service template. The mode appears in the execution command for the connector. In the Centreon interface, you don't need to specify a mode explicitly: its use is implied when you apply a service template. However, you will need to specify the correct mode for the template if you want to test the execution command for the connector in your terminal.

All available modes can be displayed by adding the --list-mode parameter to the command:

/usr/lib/centreon/plugins/centreon_microsoft_dhcp_snmp.pl \
	--plugin=apps::microsoft::dhcp::snmp::plugin \
	--list-mode

The plugin brings the following modes:

ModeLinked service template
list-subnets [code]Used for service discovery
subnets [code]App-Microsoft-Dhcp-Subnets-SNMP-custom

Available options​

Modes options​

All available options for each service template are listed below:

OptionDescription
--modeDefine the mode in which you want the plugin to be executed (see--list-mode).
--dyn-modeSpecify a mode with the module's path (advanced).
--list-modeList all available modes.
--mode-versionCheck minimal version of mode. If not, unknown error.
--versionReturn the version of the plugin.
--pass-managerDefine the password manager you want to use. Supported managers are: environment, file, keepass, hashicorpvault and teampass.
--verboseDisplay extended status information (long output).
--debugDisplay debug messages.
--filter-perfdataFilter perfdata that match the regexp. Example: adding --filter-perfdata='avg' will remove all metrics that do not contain 'avg' from performance data.
--filter-perfdata-advFilter perfdata based on a "if" condition using the following variables: label, value, unit, warning, critical, min, max. Variables must be written either %{variable} or %(variable). Example: adding --filter-perfdata-adv='not (%(value) == 0 and %(max) eq "")' will remove all metrics whose value equals 0 and that don't have a maximum value.
--explode-perfdata-maxCreate a new metric for each metric that comes with a maximum limit. The new metric will be named identically with a '_max' suffix). Example: it will split 'used_prct'=26.93%;0:80;0:90;0;100 into 'used_prct'=26.93%;0:80;0:90;0;100 'used_prct_max'=100%;;;;
--change-perfdata --extend-perfdataChange or extend perfdata. Syntax: --extend-perfdata=searchlabel,newlabel,target[,[newuom],[min],[m ax]] Common examples: Convert storage free perfdata into used: --change-perfdata='free,used,invert()' Convert storage free perfdata into used: --change-perfdata='used,free,invert()' Scale traffic values automatically: --change-perfdata='traffic,,scale(auto)' Scale traffic values in Mbps: --change-perfdata='traffic_in,,scale(Mbps),mbps' Change traffic values in percent: --change-perfdata='traffic_in,,percent()'
--extend-perfdata-groupAdd new aggregated metrics (min, max, average or sum) for groups of metrics defined by a regex match on the metrics' names. Syntax: --extend-perfdata-group=regex,namesofnewmetrics,calculation[,[ne wuom],[min],[max]] regex: regular expression namesofnewmetrics: how the new metrics' names are composed (can use $1, $2... for groups defined by () in regex). calculation: how the values of the new metrics should be calculated newuom (optional): unit of measure for the new metrics min (optional): lowest value the metrics can reach max (optional): highest value the metrics can reach Common examples: Sum wrong packets from all interfaces (with interface need --units-errors=absolute): --extend-perfdata-group=',packets_wrong,sum(packets_(discard |error)_(in|out))' Sum traffic by interface: --extend-perfdata-group='traffic_in_(.*),traffic_$1,sum(traf fic_(in|out)_$1)'
--change-short-output --change-long-outputModify the short/long output that is returned by the plugin. Syntax: --change-short-output=patternreplacementmodifier Most commonly used modifiers are i (case insensitive) and g (replace all occurrences). Example: adding --change-short-output='OKUpgi' will replace all occurrences of 'OK', 'ok', 'Ok' or 'oK' with 'Up'
--change-exitReplace an exit code with one of your choice. Example: adding --change-exit=unknown=critical will result in a CRITICAL state instead of an UNKNOWN state.
--range-perfdataRewrite the ranges displayed in the perfdata. Accepted values: 0: nothing is changed. 1: if the lower value of the range is equal to 0, it is removed. 2: remove the thresholds from the perfdata.
--filter-uomMask the units when they don't match the given regular expression.
--opt-exitReplace the exit code in case of an execution error (i.e. wrong option provided, SSH connection refused, timeout, etc). Default: unknown.
--output-ignore-perfdataRemove all the metrics from the service. The service will still have a status and an output.
--output-ignore-labelRemove the status label ("OK:", "WARNING:", "UNKNOWN:", CRITICAL:") from the beginning of the output. Example: 'OK: Ram Total:...' will become 'Ram Total:...'
--output-xmlReturn the output in XML format (to send to an XML API).
--output-jsonReturn the output in JSON format (to send to a JSON API).
--output-openmetricsReturn the output in OpenMetrics format (to send to a tool expecting this format).
--output-fileWrite output in file (can be combined with json, xml and openmetrics options). E.g.: --output-file=/tmp/output.txt will write the output in /tmp/output.txt.
--disco-formatApplies only to modes beginning with 'list-'. Returns the list of available macros to configure a service discovery rule (formatted in XML).
--disco-showApplies only to modes beginning with 'list-'. Returns the list of discovered objects (formatted in XML) for service discovery.
--float-precisionDefine the float precision for thresholds (default: 8).
--source-encodingDefine the character encoding of the response sent by the monitored resource Default: 'UTF-8'.
--hostnameName or address of the host to monitor (mandatory).
--snmp-communitySNMP community (default value: public). It is recommended to use a read-only community.
--snmp-versionVersion of the SNMP protocol. 1 for SNMP v1 (default), 2 for SNMP v2c, 3 for SNMP v3.
--snmp-portUDP port to send the SNMP request to (default: 161).
--snmp-timeoutTime to wait before sending the request again if no reply has been received, in seconds (default: 1). See also --snmp-retries.
--snmp-retriesMaximum number of retries (default: 5).
--maxrepetitionsMax repetitions value (default: 50) (only for SNMP v2 and v3).
--subsetleefHow many OID values per SNMP request (default: 50) (for get_leef method. Be cautious when you set it. Prefer to let the default value).
--snmp-autoreduceProgressively reduce the number of requested OIDs in bulk mode. Use it in case of SNMP errors (by default, the number is divided by 2).
--snmp-force-getnextUse SNMP getnext function in SNMP v2c and v3. This will request one OID at a time.
--snmp-cache-fileUse SNMP cache file.
--snmp-usernameSNMP v3 only: User name (securityName).
--authpassphraseSNMP v3 only: Pass phrase hashed using the authentication protocol defined in the --authprotocol option.
--authprotocolSNMP v3 only: Authentication protocol: MD5|SHA. Since net-snmp 5.9.1: SHA224|SHA256|SHA384|SHA512.
--privpassphraseSNMP v3 only: Privacy pass phrase (privPassword) to encrypt messages using the protocol defined in the --privprotocol option.
--privprotocolSNMP v3 only: Privacy protocol (privProtocol) used to encrypt messages. Supported protocols are: DES|AES and since net-snmp 5.9.1: AES192|AES192C|AES256|AES256C.
--contextnameSNMP v3 only: Context name (contextName), if relevant for the monitored host.
--contextengineidSNMP v3 only: Context engine ID (contextEngineID), if relevant for the monitored host, given as a hexadecimal string.
--securityengineidSNMP v3 only: Security engine ID, given as a hexadecimal string.
--snmp-errors-exitExpected status in case of SNMP error or timeout. Possible values are warning, critical and unknown (default).
--snmp-tls-transportTransport protocol for TLS communication (can be: 'dtlsudp', 'tlstcp').
--snmp-tls-our-identityX.509 certificate to identify ourselves. Can be the path to the certificate file or its contents.
--snmp-tls-their-identityX.509 certificate to identify the remote host. Can be the path to the certificate file or its contents. This option is unnecessary if the certificate is already trusted by your system.
--snmp-tls-their-hostnameCommon Name (CN) expected in the certificate sent by the host if it differs from the value of the --hostname parameter.
--snmp-tls-trust-certA trusted CA certificate used to verify a remote host's certificate. If you use this option, you must also define --snmp-tls-their-hostname.
--filter-countersOnly display some counters (regexp can be used). Example: --filter-counters='pending'
--filter-subnet-addressFilter subnets by address (can be a regexp).
--unknown-statusDefine the conditions to match for the status to be UNKNOWN. You can use the following variables: %{status}, %{name}
--warning-statusDefine the conditions to match for the status to be WARNING. You can use the following variables: %{status}, %{name}
--critical-statusDefine the conditions to match for the status to be CRITICAL. You can use the following variables: %{status}, %{name}
--warning-* --critical-*Thresholds. Can be: 'addresses-usage', 'addresses-usage-free', 'addresses-usage-prct', 'pending-offers'.

All available options for a given mode can be displayed by adding the --help parameter to the command:

/usr/lib/centreon/plugins/centreon_microsoft_dhcp_snmp.pl \
	--plugin=apps::microsoft::dhcp::snmp::plugin \
	--mode=subnets \
	--help