ISC DHCP

Plugin: go.d.plugin Module: isc_dhcpd

Overview

This collector monitors ISC DHCP lease usage by reading the DHCP client lease database (dhcpd.leases).

This collector is only supported on the following platforms:

• Linux
• BSD

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.

Setup

You can configure the isc_dhcpd collector in two ways:

Method	Best for	How to
UI	Fast setup without editing files	Go to Nodes → Configure this node → Collectors → Jobs, search for isc_dhcpd, then click + to add a job.
File	If you prefer configuring via file, or need to automate deployments (e.g., with Ansible)	Edit go.d/isc_dhcpd.conf and add a job.

important

UI configuration requires paid Netdata Cloud plan.

Prerequisites

No action required.

Configuration

Options

The following options can be defined globally: update_every, autodetection_retry.

Config options

Group	Option	Description	Default	Required
Collection	update_every	Data collection interval (seconds).	1	no
	autodetection_retry	Autodetection retry interval (seconds). Set 0 to disable.	0	no
Target	leases_path	Path to DHCP client lease database.	/var/lib/dhcp/dhcpd.leases	no
	pools	DHCP IP pools to monitor.		yes

pools

List of IP pools to monitor.

• IP range syntax: see supported formats.
• Syntax:

pools:
  - name: "POOL_NAME1"
    networks: "SPACE SEPARATED LIST OF IP RANGES"
  - name: "POOL_NAME2"
    networks: "SPACE SEPARATED LIST OF IP RANGES"

via UI

Configure the isc_dhcpd collector from the Netdata web interface:

1. Go to Nodes.
2. Select the node where you want the isc_dhcpd data-collection job to run and click the ⚙ (Configure this node). That node will run the data collection.
3. The Collectors → Jobs view opens by default.
4. In the Search box, type isc_dhcpd (or scroll the list) to locate the isc_dhcpd collector.
5. Click the + next to the isc_dhcpd collector to add a new job.
6. Fill in the job fields, then click Test to verify the configuration and Submit to save.
   • Test runs the job with the provided settings and shows whether data can be collected.
   • If it fails, an error message appears with details (for example, connection refused, timeout, or command execution errors), so you can adjust and retest.

via File

The configuration file name for this integration is go.d/isc_dhcpd.conf.

The file format is YAML. Generally, the structure is:

update_every: 1
autodetection_retry: 0
jobs:
  - name: some_name1
  - name: some_name2

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/isc_dhcpd.conf

Examples

Basic

A basic example configuration.

Config

jobs:
  - name: local
    pools:
      - name: lan
        networks: "192.168.0.0/24 192.168.1.0/24 192.168.2.0/24"
      - name: wifi
        networks: "10.0.0.0/24"

Alerts

There are no alerts configured by default for this integration.

Metrics

Metrics grouped by scope.

The scope defines the instance that the metric belongs to. An instance is uniquely identified by a set of labels.

Per ISC DHCP instance

These metrics refer to the entire monitored application.

This scope has no labels.

Metrics:

Metric	Description	Dimensions	Unit
isc_dhcpd.active_leases_total	Active Leases Total	active	leases

Per ISC DHCP instance

These metrics refer to the DHCP pool.

Labels:

Label	Description
dhcp_pool_name	The DHCP pool name defined in the collector configuration.

Metrics:

Metric	Description	Dimensions	Unit
isc_dhcpd.dhcp_pool_utilization	DHCP Pool Utilization	utilization	percent
isc_dhcpd.dhcp_pool_active_leases	Active Leases Total	active	leases

Troubleshooting

Diagnostics

Debug Mode

Important: Debug mode is not supported for data collection jobs created via the UI using the Dyncfg feature.

To troubleshoot issues with the isc_dhcpd 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 isc_dhcpd

  To debug a specific job:

  ./go.d.plugin -d -m isc_dhcpd -j jobName

Getting Logs

If you're encountering problems with the isc_dhcpd collector, follow these steps to retrieve logs and identify potential issues:

• Run the command specific to your system (systemd, non-systemd, or Docker container).
• Examine the output for any warnings or error messages that might indicate issues. These messages should provide clues about the root cause of the problem.

System with systemd

Use the following command to view logs generated since the last Netdata service restart:

journalctl _SYSTEMD_INVOCATION_ID="$(systemctl show --value --property=InvocationID netdata)" --namespace=netdata --grep isc_dhcpd

System without systemd

Locate the collector log file, typically at /var/log/netdata/collector.log, and use grep to filter for collector's name:

grep isc_dhcpd /var/log/netdata/collector.log

Note: This method shows logs from all restarts. Focus on the latest entries for troubleshooting current issues.

Docker Container

If your Netdata runs in a Docker container named "netdata" (replace if different), use this command:

docker logs netdata 2>&1 | grep isc_dhcpd