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.

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	Dimensions	Unit
isc_dhcpd.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	Dimensions	Unit
isc_dhcpd.dhcp_pool_utilization	utilization	percent
isc_dhcpd.dhcp_pool_active_leases	active	leases

Alerts

There are no alerts configured by default for this integration.

Setup

Prerequisites

No action required.

Configuration

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_name1

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

Options

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

Config options

Name	Description	Default	Required
update_every	Data collection frequency.	1	no
autodetection_retry	Recheck interval in seconds. Zero means no recheck will be scheduled.	0	no
leases_path	Path to DHCP client lease database.	/var/lib/dhcp/dhcpd.leases	no
pools	List of 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"

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"

Troubleshooting

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

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