---
title: "Global network set"
description: "Reference for the GlobalNetworkSet resource in Calico Open Source that defines a cluster-scoped set of CIDRs referenced by network policy."
product: "Calico Open Source"
version: "3.32 (latest)"
section: "Reference"
canonical_url: "https://docs.tigera.io/calico/latest/reference/resources/globalnetworkset"
---

# Global network set

A global network set resource (GlobalNetworkSet) represents an arbitrary set of IP subnetworks/CIDRs, allowing it to be matched by Calico policy. Network sets are useful for applying policy to traffic coming from (or going to) external, non-Calico, networks.

The metadata for each network set includes a set of labels. When Calico is calculating the set of IPs that should match a source/destination selector within a [global network policy](https://docs.tigera.io/calico/latest/reference/resources/globalnetworkpolicy.md) rule, or within a [network policy](https://docs.tigera.io/calico/latest/reference/resources/networkpolicy.md) rule whose `namespaceSelector` includes `global()`, it includes the CIDRs from any network sets that match the selector.

> **SECONDARY:** Since Calico matches packets based on their source/destination IP addresses, Calico rules may not behave as expected if there is NAT between the Calico-enabled node and the networks listed in a network set. For example, in Kubernetes, incoming traffic via a service IP is typically SNATed by the kube-proxy before reaching the destination host so Calico's workload policy will see the kube-proxy's host's IP as the source instead of the real source.

## Sample YAML

```yaml
apiVersion: projectcalico.org/v3
kind: GlobalNetworkSet
metadata:
  name: a-name-for-the-set
  labels:
    role: external-database
spec:
  nets:
    - 198.51.100.0/28
    - 203.0.113.0/24
```

## Global network set definition

### Metadata

| Field  | Description                                | Accepted Values                                   | Schema |
| ------ | ------------------------------------------ | ------------------------------------------------- | ------ |
| name   | The name of this network set.              | Lower-case alphanumeric with optional `-` or `-`. | string |
| labels | A set of labels to apply to this endpoint. |                                                   | map    |

### Spec

| Field | Description                                  | Accepted Values                                        | Schema | Default |
| ----- | -------------------------------------------- | ------------------------------------------------------ | ------ | ------- |
| nets  | The IP networks/CIDRs to include in the set. | Valid IPv4 or IPv6 CIDRs, for example "192.0.2.128/25" | list   |         |