---
title: "Configure default IP pools"
description: "Set the default Calico Enterprise IP pool CIDR, encapsulation, and NAT outgoing values during Tigera Operator installation through the Installation resource."
product: "Calico Enterprise"
version: "3.23 (latest)"
section: "Networking"
canonical_url: "https://docs.tigera.io/calico-enterprise/latest/networking/ipam/initial-ippool"
---

# Configure default IP pools

## Big picture

Configure the default IP pool values to use during Tigera Operator installation.

## Value

During Tigera Operator installation, you must configure the CIDR range to use for pods that reflects your environment.

## Concepts

### Kubernetes pod CIDR

The **Kubernetes pod CIDR** is the expected IP address range for pod IPs. It is defined for the entire cluster, and is used by various Kubernetes components to determine if an IP belongs to a pod. For example, kube-proxy treats traffic differently if an IP is from a pod than if it is not. All pod IPs must be in the CIDR range for Kubernetes to function correctly.

### Tigera Operator and IP pools

[Calico IP pools](https://docs.tigera.io/calico-enterprise/latest/reference/resources/ippool.md) are ranges of IP addresses that Calico uses to assign to pods; the ranges must within the Kubernetes pod CIDR.

The Tigera Operator reads the [Installation](https://docs.tigera.io/calico-enterprise/latest/reference/installation/api.md#installation) resource and configures the default Calico IP pool. Note the following:

- Default fields for any that are omitted:

  - CIDR: 192.168.0.0/16
  - Encapsulation: IPIP
  - NodeSelector: all()
  - NATOutgoing: Enabled

- IP pools are only used when Calico is used for pod networking, IP pools are not utilized when using other pod networking solutions.

- To make changes to the IP pools after Tigera Operator install, you may use [calicoctl](https://docs.tigera.io/calico-enterprise/latest/reference/clis/calicoctl.md) or kubectl. If you make the changes to the IP Pool in the Installation resource (Operator IPPool) after installation, the changes are not applied.

## Before you begin...

- Verify that your IP pool is within the Kubernetes pod CIDR
- If you are using encapsulation (IP in IP or VXLAN), ensure that the traffic is allowed on your network
- You are making these changes for a cluster that has not yet had Calico Enterprise deployed.

## How to

1. Download the custom-resource.yaml file.

2. Edit the [Installation resource](https://docs.tigera.io/calico-enterprise/latest/reference/installation/api.md#installation). **Required values**: `cidr:` **Empty values**: Defaulted

   ```bash
   apiVersion: operator.tigera.io/v1
   kind: Installation
   metadata:
     name: default
   spec:
     calicoNetwork:
      ipPools:
         - cidr: "192.168.0.0/16"
           encapsulation: "IPIP"
           nodeSelector: "label == 'value'"
           natOutgoing: "Enabled"
   ```

3. Apply the manifest and continue with your installation as normal.

## Additional resources

- [IP pool resource](https://docs.tigera.io/calico-enterprise/latest/reference/resources/ippool.md)
- Use [calicoctl](https://docs.tigera.io/calico-enterprise/latest/reference/clis/calicoctl.md) or `kubectl` to edit the IPPool resource.