Configuring MetalLB address pools

• About the address pool custom resource
• Configuring an address pool
• Example address pool configurations
  • Example: IPv4 and CIDR ranges
  • Example: Reserve IP addresses
  • Example: IPv6 address pool
• Next steps

As a cluster administrator, you can add, modify, and delete address pools. The MetalLB Operator uses the address pool custom resources to set the IP addresses that MetalLB can assign to services.

About the address pool custom resource

The fields for the address pool custom resource are described in the following table.

Configuring an address pool

As a cluster administrator, you can add address pools to your cluster to control the IP addresses that MetaLLB can assign to load-balancer services.

Prerequisites

• Install the OpenShift CLI (oc).

• Log in as a user with cluster-admin privileges.

Procedure

1. Create a file, such as addresspool.yaml, with content like the following example:

   apiVersion: metallb.io/v1alpha1
   kind: AddressPool
   metadata:
     namespace: metallb-system
     name: doc-example
   spec:
     protocol: layer2
     addresses:
     - 203.0.113.1-203.0.113.10
     - 203.0.113.65-203.0.113.75

2. Apply the configuration for the address pool:

   $ oc apply -f addresspool.yaml

Verification

• View the address pool:

  $ oc describe -n metallb-system addresspool doc-example

  Example output

  Name:         doc-example
  Namespace:    metallb-system
  Labels:       <none>
  Annotations:  <none>
  API Version:  metallb.io/v1alpha1
  Kind:         AddressPool
  Metadata:
    ...
  Spec:
    Addresses:
      203.0.113.1-203.0.113.10
      203.0.113.65-203.0.113.75
    Auto Assign:  true
    Protocol:     layer2
  Events:         <none>

Confirm that the address pool name, such as doc-example, and the IP address ranges appear in the output.

Example address pool configurations

Example: IPv4 and CIDR ranges

You can specify a range of IP addresses in CIDR notation. You can combine CIDR notation with the notation that uses a hyphen to separate lower and upper bounds.

apiVersion: metallb.io/v1beta1
kind: AddressPool
metadata:
  name: doc-example-cidr
  namespace: metallb-system
spec:
  protocol: layer2
  addresses:
  - 192.168.100.0/24
  - 192.168.200.0/24
  - 192.168.255.1-192.168.255.5

Example: Reserve IP addresses

You can set the autoAssign field to false to prevent MetalLB from automatically assigning the IP addresses from the pool. When you add a service, you can request a specific IP address from the pool or you can specify the pool name in an annotation to request any IP address from the pool.

apiVersion: metallb.io/v1beta1
kind: AddressPool
metadata:
  name: doc-example-reserved
  namespace: metallb-system
spec:
  protocol: layer2
  addresses:
  - 10.0.100.0/28
  autoAssign: false

Example: IPv6 address pool

You can add address pools that use IPv6. The following example shows a single IPv6 range. However, you can specify multiple ranges in the addresses list, just like several IPv4 examples.

apiVersion: metallb.io/v1beta1
kind: AddressPool
metadata:
  name: doc-example-ipv6
  namespace: metallb-system
spec:
  protocol: layer2
  addresses:
  - 2002:2:2::1-2002:2:2::100

Next steps

• Configuring services to use MetalLB