Notification events

Neutron emits legacy (unversioned) notifications. Payload fields follow the Neutron API resource schema for the corresponding operation. There is no formal backward compatibility guarantee for notification payloads.

Resource CRUD events

For every REST API resource exposed by Neutron and its extensions, create, update, and delete operations emit notifications with the following event type patterns:

Event type	When emitted
<resource>.create.start	Before the create operation runs
<resource>.create.end	After a successful create (HTTP 2xx)
<resource>.update.start	Before the update operation runs
<resource>.update.end	After a successful update (HTTP 2xx)
<resource>.delete.start	Before the delete operation runs
<resource>.delete.end	After a successful delete (HTTP 2xx/204)

<resource> is the singular resource name used internally by the API (for example, network, subnet, port, router, security_group). Extension resources follow the same pattern using their registered resource name.

Payload format

Create

• <resource>.create.start — the request body sent to the API.

  Example for network.create.start:

  {
      "network": {
          "name": "private-net",
          "admin_state_up": true
      }
  }
  

• <resource>.create.end — the API response body containing the created resource.

  Example for network.create.end:

  {
      "network": {
          "id": "9eaa96ed-c2d2-45a7-a6d5-5f276a3a1b54",
          "name": "private-net",
          "admin_state_up": true,
          "status": "ACTIVE",
          "project_id": "0e33d3b1881045c3ac1b1cb9df3e0477",
      }
  }
  

Bulk create operations send a single *.start notification with the bulk request body and a single *.end notification with the bulk response body.

Update

• <resource>.update.start — the request body with an additional id field set to the resource identifier.

  Example for network.update.start:

  {
      "network": {
          "name": "renamed-net"
      },
      "id": "9eaa96ed-c2d2-45a7-a6d5-5f276a3a1b54"
  }
  

• <resource>.update.end — the API response body containing the updated resource.

Delete

• <resource>.delete.start — a dictionary containing the resource ID:

  {
      "network_id": "9eaa96ed-c2d2-45a7-a6d5-5f276a3a1b54"
  }
  

• <resource>.delete.end — the deleted resource dictionary plus the resource ID field:

  {
      "network_id": "9eaa96ed-c2d2-45a7-a6d5-5f276a3a1b54",
      "network": {
          "id": "9eaa96ed-c2d2-45a7-a6d5-5f276a3a1b54",
          "name": "private-net",
          "admin_state_up": true,
          "status": "ACTIVE",
          "project_id": "0e33d3b1881045c3ac1b1cb9df3e0477"
      }
  }
  

Core resources

The following core resources emit CRUD notifications when created, updated, or deleted through the API:

• network

• subnet

• subnetpool

• port

L3 and security resources (when the corresponding extensions are loaded) include router, floatingip, security_group, and security_group_rule.

Any other API extension that exposes standard CRUD endpoints also emits notifications following the same pattern. Refer to the Network API reference for the full list of resources and their attributes.

Example: port update

Full notification for port.update.end:

{
    "priority": "INFO",
    "event_type": "port.update.end",
    "timestamp": "2026-05-28T12:00:00.000000",
    "publisher_id": "network.myhost",
    "message_id": "f6b2e828-4a28-47b7-8f9d-96a3185bcdb0",
    "payload": {
        "port": {
            "id": "42a5e466-2c4e-4c58-b357-8b2459891066",
            "name": "server-port",
            "network_id": "9eaa96ed-c2d2-45a7-a6d5-5f276a3a1b54",
            "mac_address": "fa:16:3e:42:61:26",
            "admin_state_up": true,
            "status": "ACTIVE",
            "device_id": "instance-uuid",
            "device_owner": "compute:nova",
            "fixed_ips": [
                {
                    "subnet_id": "b9304367-404e-4c1a-9bc3-abac6cc92d1d",
                    "ip_address": "192.168.1.10"
                }
            ],
            "project_id": "0e33d3b1881045c3ac1b1cb9df3e0477"
        }
    }
}

Special events

In addition to the generic CRUD notifications, Neutron emits the following special-purpose events.

Router interface

Emitted when a subnet is added to or removed from a router.

Event type	When emitted
router.interface.create	After a subnet is added to a router
router.interface.delete	After a subnet is removed from a router

Payload:

{
    "router_interface": {
        "id": "<router_id>",
        "project_id": "<project_id>",
        "port_id": "<port_id>",
        "network_id": "<network_id>",
        "subnet_id": "<subnet_id>",
        "subnet_ids": ["<subnet_id>"]
    }
}

Resource tags

Emitted when tags are created, updated, or deleted on a taggable resource. Tag operations emit both *.start and *.end pairs.

Event type	When emitted
tag.create.start / tag.create.end	Before and after tags are created on a resource
tag.update.start / tag.update.end	Before and after tags are updated on a resource
tag.delete.start / tag.delete.end	Before and after tags are deleted from a resource
tag.delete_all.start / tag.delete_all.end	Before and after all tags are deleted from a resource

Payload:

{
    "obj_resource": "<resource_type>",
    "obj_resource_id": "<resource_id>",
    "tags": ["tag1", "tag2"]
}

The tags field is present when tags are being set. Taggable resources include networks, subnets, subnetpools, ports, routers, floating IPs, security groups, security group rules, trunks, and other resources that support standard attributes.

Agent scheduling

Emitted when a network or router is assigned to or removed from an agent.

Event type	When emitted
dhcp_agent.network.add	Network scheduled to a DHCP agent
dhcp_agent.network.remove	Network removed from a DHCP agent
l3_agent.router.add	Router scheduled to an L3 agent
l3_agent.router.remove	Router removed from an L3 agent

Payload for DHCP agent events:

{
    "agent": {
        "id": "<agent_id>",
        "network_id": "<network_id>"
    }
}

Payload for L3 agent events:

{
    "agent": {
        "id": "<agent_id>",
        "router_id": "<router_id>"
    }
}

Metering

The metering agent periodically reports traffic counters.

Event type	When emitted
l3.meter	Default traffic report
l3.meter.<granularity>	Granular traffic report

Payload:

{
    "pkts": 1000,
    "bytes": 1500000,
    "time": 300,
    "first_update": "2026-05-28T11:55:00.000000",
    "last_update": "2026-05-28T12:00:00.000000",
    "host": "network-node-1",
    "label_id": "<metering_label_id>",
    "project_id": "<project_id>"
}

When granular traffic data is enabled, the payload may also include resource_id, label_name, and label_shared fields instead of or in addition to label_id.

Usage audit

The neutron-usage-audit cron script emits existence notifications for all resources currently in the database. These are used by billing and monitoring systems.

Event type	Payload key
network.exists	network
subnet.exists	subnet
port.exists	port
router.exists	router
floatingip.exists	floatingip

Each payload contains the full resource dictionary under the corresponding key, for example {"network": {<network_dict>}}.