I have an AKS Automatic cluster with a load balancer (kube-apiserver) that was automatically created during provisioning. The backend pool of this load balancer has the following IP addresses:

[
  {
    "ipAddress": "10.226.0.10",
    "name": "10.226.0.10",
    "subnet": {
      "id": "/subscriptions/.../resourceGroups/rg-training-dev-infrastructure/providers/Microsoft.Network/virtualNetworks/aks-vnet-30931460/subnets/aks-apiserver-subnet"
    }
  },
  {
    "ipAddress": "10.226.0.11",
    "name": "10.226.0.11",
    "subnet": {
      "id": "/subscriptions/.../resourceGroups/rg-training-dev-infrastructure/providers/Microsoft.Network/virtualNetworks/aks-vnet-30931460/subnets/aks-apiserver-subnet"
    }
  },
  {
    "ipAddress": "10.226.0.5",
    "name": "10.226.0.5",
    "subnet": {
      "id": "/subscriptions/.../resourceGroups/rg-training-dev-infrastructure/providers/Microsoft.Network/virtualNetworks/aks-vnet-30931460/subnets/aks-apiserver-subnet"
    }
  },
  {
    "ipAddress": "10.226.0.6",
    "name": "10.226.0.6",
    "subnet": {
      "id": "/subscriptions/.../resourceGroups/rg-training-dev-infrastructure/providers/Microsoft.Network/virtualNetworks/aks-vnet-30931460/subnets/aks-apiserver-subnet"
    }
  },
  {
    "ipAddress": "10.226.0.8",
    "name": "10.226.0.8",
    "subnet": {
      "id": "/subscriptions/.../resourceGroups/rg-training-dev-infrastructure/providers/Microsoft.Network/virtualNetworks/aks-vnet-30931460/subnets/aks-apiserver-subnet"
    }
  },
  {
    "ipAddress": "10.226.0.9",
    "name": "10.226.0.9",
    "subnet": {
      "id": "/subscriptions/.../resourceGroups/rg-training-dev-infrastructure/providers/Microsoft.Network/virtualNetworks/aks-vnet-30931460/subnets/aks-apiserver-subnet"
    }
  }
]

I checked the VMSS instances, pods, and endpoints but these IPs do not seem to be associated with any of them (they are all using 10.224.x.x). The API server is configured to use the load balancer frontend IP, but I can’t find any resources using these backend IPs.

Here is the description of the Kubernetes service:

$ kubectl describe svc kubernetes
Name:              kubernetes
Namespace:         default
Labels:            component=apiserver
                   provider=kubernetes
Annotations:       <none>
Selector:          <none>
Type:              ClusterIP
IP Family Policy:  SingleStack
IP Families:       IPv4
IP:                10.0.0.1
IPs:               10.0.0.1
Port:              https  443/TCP
TargetPort:        443/TCP
Endpoints:         10.226.0.4:443
Session Affinity:  None
Events:            <none>

What these IPs in the backend pool are associated with?