---
title: "Overriding DHCP Inheritance"
canonical: "https://docs.infoblox.com/space/BloxOneDDI/186466634/Overriding%20DHCP%20Inheritance"
format: markdown
---
<span style="color: #000000">DHCP properties configured at the IP Space level apply to the DHCP configuration falling underneath this IP Space, for example address block, subnet, etc. You can choose to keep the inherited properties or override them when you configure the properties for an object. For example, you can override the values of DHCP properties inherited from a parent object and enter unique values for a network that is configured for DHCP. </span>

> ⚠️ ### Note
> ⚠️ 
> ⚠️ <span style="color: #000000">The inheritance configuration is set to </span><span style="color: #000000">**Inherit**</span><span style="color: #000000"> by default while configuring via the Infoblox Portal or API. You must explicitly choose </span><span style="color: #000000">**Override**</span><span style="color: #000000"> from the Infoblox Portal or API to choose a custom value.</span>

## <span style="color: #000000">Overriding an Inherited Value from the Infoblox Portal</span>

<span style="color: #000000">To override an inherited value, complete the following:</span>

1. <span style="color: #000000">Toggle </span><span style="color: #000000">**Override**</span><span style="color: #000000">. </span>
2. <span style="color: #000000">Enter a new value.</span>

## <span style="color: #000000">Overriding an Inherited Value from the API</span>

<span style="color: #000000">To override an inherited value from the API, specify the following:</span>

`"inheritance_sources": {`  
  
`                           "dhcp_config": {`  
  
`                               "allow_unknown": {`  
  
`                                   "action": "override"`  
  
`                               }`  
  
`                           }`  
  
`                        }`  
  
  
Here is an example of global parameters:

`{`  
`  "result": {`  
`    "address": "10.1.0.0",`  
`    "asm_config": {`  
`      "asm_threshold": 0,`  
`      "enable": true,`  
`      "enable_notification": true,`  
`      "forecast_period": 14,`  
`      "growth_factor": 0,`  
`      "growth_type": "percent",`  
`      "history": 30,`  
`      "min_total": 10,`  
`      "min_unused": 0,`  
`      "reenable_date": "1970-01-01T00:00:00Z"`  
`    },`  
`    "asm_scope_flag": 0,`  
`    "cidr": 24,`  
`    "comment": "",`  
`    "compartment_id": "",`  
`    "created_at": "2020-01-13T16:44:15.996060Z",`  
`    "ddns_client_update": "client",`  
`    "ddns_conflict_resolution_mode": "check_with_dhcid",`  
`    "ddns_domain": "",`  
`    "ddns_generate_name": false,`  
`    "ddns_generated_prefix": "myhost",`  
`    "ddns_send_updates": true,`  
`    "ddns_ttl_percent": 0,`  
`    "ddns_update_on_renew": false,`  
`    "ddns_use_conflict_resolution": true,`  
`    "delegation": "",`  
`    "dhcp_config": {`  
`      "abandoned_reclaim_time": 0,`  
`      "abandoned_reclaim_time_v6": 0,`  
`      "allow_unknown": true,`  
`      "allow_unknown_v6": true,`  
`      "echo_client_id": true,`  
`      "filters": [],`  
`      "filters_large_selection": [],`  
`      "filters_v6": [],`  
`      "ignore_client_uid": false,`  
`      "ignore_list": [],`  
`      "lease_time": 3600,`  
`      "lease_time_v6": 3600`  
`    },`  
`    "dhcp_options": [],`  
`    "dhcp_utilization": {`  
`      "dhcp_free": "0",`  
`      "dhcp_total": "0",`  
`      "dhcp_used": "0",`  
`      "dhcp_utilization": 0`  
`    },`  
`    "discovery_attrs": null,`  
`    "discovery_metadata": null,`  
`    "external_keys": null,`  
`    "federated_realms": [],`  
`    "header_option_filename": "",`  
`    "header_option_server_address": "",`  
`    "header_option_server_name": "",`  
`    "hostname_rewrite_char": "",`  
`    "hostname_rewrite_enabled": false,`  
`    "hostname_rewrite_regex": "",`  
`    "id": "ipam/address_block/ef9bd21e-3623-11ea-91fd-8af3e42772cf",`  
`    "inheritance_parent": "ipam/address_block/cbb6a009-c80e-11e9-8757-0a586460226b",`  
`    "inheritance_sources": {`  
`      "asm_config": {`  
`        "asm_enable_block": {`  
`          "action": "inherit",`  
`          "display_name": "Global DHCP Properties",`  
`          "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`          "value": {`  
`            "enable": true,`  
`            "enable_notification": true,`  
`            "reenable_date": "1970-01-08T01:01:00Z"`  
`          }`  
`        },`  
`        "asm_growth_block": {`  
`          "action": "inherit",`  
`          "display_name": "Global DHCP Properties",`  
`          "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`          "value": {`  
`            "growth_factor": 20,`  
`            "growth_type": "count"`  
`          }`  
`        },`  
`        "asm_threshold": {`  
`          "action": "inherit",`  
`          "display_name": "Global DHCP Properties",`  
`          "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`          "value": 12`  
`        },`  
`        "forecast_period": {`  
`          "action": "inherit",`  
`          "display_name": "Global DHCP Properties",`  
`          "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`          "value": 14`  
`        },`  
`        "history": {`  
`          "action": "inherit",`  
`          "display_name": "Global DHCP Properties",`  
`          "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`          "value": 30`  
`        },`  
`        "min_total": {`  
`          "action": "inherit",`  
`          "display_name": "Global DHCP Properties",`  
`          "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`          "value": 10`  
`        },`  
`        "min_unused": {`  
`          "action": "inherit",`  
`          "display_name": "Global DHCP Properties",`  
`          "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`          "value": 20`  
`        }`  
`      },`  
`      "ddns_client_update": {`  
`        "action": "inherit",`  
`        "display_name": "Global DHCP Properties",`  
`        "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`        "value": "ignore"`  
`      },`  
`      "ddns_conflict_resolution_mode": {`  
`        "action": "inherit",`  
`        "display_name": "Global DHCP Properties",`  
`        "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`        "value": "check_with_dhcid"`  
`      },`  
`      "ddns_enabled": {`  
`        "action": "inherit",`  
`        "display_name": "Global DHCP Properties",`  
`        "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`        "value": false`  
`      },`  
`      "ddns_hostname_block": {`  
`        "action": "inherit",`  
`        "display_name": "Global DHCP Properties",`  
`        "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`        "value": {`  
`          "ddns_generate_name": true,`  
`          "ddns_generated_prefix": "myhost"`  
`        }`  
`      },`  
`      "ddns_ttl_percent": {`  
`        "action": "inherit",`  
`        "display_name": "Global DHCP Properties",`  
`        "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`        "value": 0`  
`      },`  
`      "ddns_update_block": {`  
`        "action": "inherit",`  
`        "display_name": "Global DHCP Properties",`  
`        "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`        "value": {`  
`          "ddns_domain": "http://example.com .",`  
`          "ddns_send_updates": true`  
`        }`  
`      },`  
`      "ddns_update_on_renew": {`  
`        "action": "inherit",`  
`        "display_name": "Global DHCP Properties",`  
`        "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`        "value": false`  
`      },`  
`      "ddns_use_conflict_resolution": {`  
`        "action": "inherit",`  
`        "display_name": "Global DHCP Properties",`  
`        "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`        "value": true`  
`      },`  
`      "dhcp_config": {`  
`        "abandoned_reclaim_time": {`  
`          "action": "override",`  
`          "display_name": "IPAM Address Block '10.0.0.0/8'",`  
`          "source": "ipam/address_block/cbb6a009-c80e-11e9-8757-0a586460226b",`  
`          "value": 0`  
`        },`  
`        "abandoned_reclaim_time_v6": {`  
`          "action": "override",`  
`          "display_name": "IPAM Address Block '10.0.0.0/8'",`  
`          "source": "ipam/address_block/cbb6a009-c80e-11e9-8757-0a586460226b",`  
`          "value": 0`  
`        },`  
`        "allow_unknown": {`  
`          "action": "inherit",`  
`          "display_name": "Global DHCP Properties",`  
`          "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`          "value": false`  
`        },`  
`        "allow_unknown_v6": {`  
`          "action": "inherit",`  
`          "display_name": "Global DHCP Properties",`  
`          "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`          "value": true`  
`        },`  
`        "echo_client_id": {`  
`          "action": "inherit",`  
`          "display_name": "Global DHCP Properties",`  
`          "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`          "value": true`  
`        },`  
`        "filters": {`  
`          "action": "inherit",`  
`          "display_name": "Global DHCP Properties",`  
`          "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`          "value": []`  
`        },`  
`        "filters_v6": {`  
`          "action": "inherit",`  
`          "display_name": "Global DHCP Properties",`  
`          "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`          "value": []`  
`        },`  
`        "ignore_client_uid": {`  
`          "action": "inherit",`  
`          "display_name": "Global DHCP Properties",`  
`          "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`          "value": false`  
`        },`  
`        "ignore_list": {`  
`          "action": "inherit",`  
`          "display_name": "Global DHCP Properties",`  
`          "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`          "value": []`  
`        },`  
`        "lease_time": {`  
`          "action": "inherit",`  
`          "display_name": "Global DHCP Properties",`  
`          "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`          "value": 1740`  
`        },`  
`        "lease_time_v6": {`  
`          "action": "inherit",`  
`          "display_name": "Global DHCP Properties",`  
`          "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`          "value": 3600`  
`        }`  
`      },`  
`      "dhcp_options": {`  
`        "action": "inherit",`  
`        "value": [`  
`          {`  
`            "action": "inherit",`  
`            "display_name": "Global DHCP Properties",`  
`            "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`            "value": {`  
`              "option": {`  
`                "group": null,`  
`                "option_code": "dhcp/option_code/ebe89708-0252-11eb-bc59-a68510dc5cf0",`  
`                "option_value": "12",`  
`                "type": "option"`  
`              },`  
`              "overriding_group": null`  
`            }`  
`          },`  
`          {`  
`            "action": "inherit",`  
`            "display_name": "Global DHCP Properties",`  
`            "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`            "value": {`  
`              "option": {`  
`                "group": null,`  
`                "option_code": "dhcp/option_code/428d6b88-92c2-11ea-8ead-c28c972a2a2a",`  
`                "option_value": "12",`  
`                "type": "option"`  
`              },`  
`              "overriding_group": null`  
`            }`  
`          },`  
`          {`  
`            "action": "inherit",`  
`            "display_name": "Global DHCP Properties",`  
`            "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`            "value": {`  
`              "option": {`  
`                "group": "dhcp/option_group/97038ca7-b0b9-11ea-a6ae-dab68f2e59ab",`  
`                "option_code": null,`  
`                "option_value": "",`  
`                "type": "group"`  
`              },`  
`              "overriding_group": null`  
`            }`  
`          }`  
`        ]`  
`      },`  
`      "header_option_filename": {`  
`        "action": "inherit",`  
`        "display_name": "Global DHCP Properties",`  
`        "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`        "value": ""`  
`      },`  
`      "header_option_server_address": {`  
`        "action": "inherit",`  
`        "display_name": "Global DHCP Properties",`  
`        "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`        "value": ""`  
`      },`  
`      "header_option_server_name": {`  
`        "action": "inherit",`  
`        "display_name": "Global DHCP Properties",`  
`        "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`        "value": ""`  
`      },`  
`      "hostname_rewrite_block": {`  
`        "action": "inherit",`  
`        "display_name": "Global DHCP Properties",`  
`        "source": "dhcp/global/47425f38-a1af-11e9-b7bf-0a5864600414",`  
`        "value": {`  
`          "hostname_rewrite_char": "",`  
`          "hostname_rewrite_enabled": true,`  
`          "hostname_rewrite_regex": "[^a-zA-Z0-9.]"`  
`        }`  
`      }`  
`    },`  
`    "name": "",`  
`    "parent": "ipam/address_block/cbb6a009-c80e-11e9-8757-0a586460226b",`  
`    "protocol": "ip4",`  
`    "space": "ipam/ip_space/75a9ba7f-c80e-11e9-b635-0a586460298f",`  
`    "tags": null,`  
`    "threshold": {`  
`      "enabled": false,`  
`      "high": 0,`  
`      "low": 0`  
`    },`  
`    "updated_at": "2024-05-03T16:50:52.930189Z",`  
`    "usage": [`  
`      "IPAM"`  
`    ],`  
`    "utilization": {`  
`      "abandon_utilization": 0,`  
`      "abandoned": "0",`  
`      "dynamic": "0",`  
`      "free": "256",`  
`      "static": "0",`  
`      "total": "256",`  
`      "used": "0",`  
`      "utilization": 0`  
`    },`  
`    "utilization_v6": {`  
`      "abandoned": "0",`  
`      "dynamic": "0",`  
`      "static": "0",`  
`      "total": "0",`  
`      "used": "0"`  
`    }`  
`  }`  
`}`

If you use the following API syntax,

<sup>GET http://.../child/1, </sup>

it is equivalent to,

<sup>GET http://.../child/1?_inherit=none.</sup>

Use the following syntax to retrieve the values for child with full inheritance information:

<sup>GET </sup><sup>[http://.../child/1?_inherit=full](#)</sup>

## <span style="color: #333300">Granular Control of DHCP Inheritance</span>

<span style="color: #333300">After configuring the DHCP options in an object, you can configure the inheritance for each item individually.</span>

<span style="color: #333300">To configure inheritance granularly, complete the following:</span>

1. <span style="color: #333300">From the Infoblox Portal, click </span><span style="color: #333300">**Manage**</span><span style="color: #333300"> > </span><span style="color: #333300">**IPAM/DHCP**</span><span style="color: #333300"> > </span><span style="color: #333300">**Object_name**</span><span style="color: #333300">. This can be an IP Space, Address Block, Range, or Subnet.</span>
2. <span style="color: #333300">Click </span><span style="color: #000000">☰</span><span style="color: #333300"> > </span><span style="color: #333300">**Edit**</span><span style="color: #333300"> or select the respective record and click the </span><span style="color: #333300">**Edit**</span><span style="color: #333300"> button to modify the object.</span>
3. <span style="color: #333300">Navigate to the </span><span style="color: #333300">**DHCP Options**</span><span style="color: #333300"> pane.</span>
4. <span style="color: #333300">You can </span><span style="color: #333300">**Inherit**</span><span style="color: #333300">, </span><span style="color: #333300">**Override**</span><span style="color: #333300"> or </span><span style="color: #333300">**Block**</span><span style="color: #333300"> each entry independently by configuring the following options:</span>
  - <span style="color: #333300">**Block all inherited options: **</span><span style="color: #333300">Clear the check box to configure inheritance granularly. Select the check box to block the values inherited from the Global DHCP Configuration. </span>
    - <span style="color: #333300">**Inherit**</span><span style="color: #333300">: Inherits the value from the Global DHCP Configuration. </span>
    - <span style="color: #333300">**Override**</span><span style="color: #333300">: Choose to override the inherited value and specify a custom value.</span>
    - <span style="color: #333300">**Block**</span><span style="color: #333300">: Choose this option to block the DHCP option.</span>
5. <span style="color: #333300">Modify the details and click </span><span style="color: #333300">**Save & Close**</span><span style="color: #333300"> to save the record or click </span><span style="color: #333300">**Cancel**</span><span style="color: #333300"> to cancel.</span>