"network_rules": {
				Type:     schema.TypeList,
				Optional: true,
				Computed: true,
				MaxItems: 1,
				Elem: &schema.Resource{
					Schema: map[string]*schema.Schema{
						"bypass": {
							Type:     schema.TypeSet,
							Optional: true,
							Computed: true,
							Elem: &schema.Schema{
								Type: schema.TypeString,
								ValidateFunc: validation.StringInSlice([]string{
									string(storage.AzureServices),
									string(storage.Logging),
									string(storage.Metrics),
									string(storage.None),
								}, true),
							},
							Set: schema.HashString,
						},

						"ip_rules": {
							Type:     schema.TypeSet,
							Optional: true,
							Computed: true,
							Elem: &schema.Schema{
								Type:         schema.TypeString,
								ValidateFunc: validate.StorageAccountIPRule,
							},
							Set: schema.HashString,
						},

						"virtual_network_subnet_ids": {
							Type:     schema.TypeSet,
							Optional: true,
							Computed: true,
							Elem:     &schema.Schema{Type: schema.TypeString},
							Set:      schema.HashString,
						},

						"default_action": {
							Type:     schema.TypeString,
							Required: true,
							ValidateFunc: validation.StringInSlice([]string{
								string(storage.DefaultActionAllow),
								string(storage.DefaultActionDeny),
							}, false),
						},
					},
				},
			},
...
func flattenStorageAccountNetworkRules(input *storage.NetworkRuleSet) []interface{} {
	if input == nil {
		return []interface{}{}
	}

	networkRules := make(map[string]interface{})

	networkRules["ip_rules"] = schema.NewSet(schema.HashString, flattenStorageAccountIPRules(input.IPRules))
	networkRules["virtual_network_subnet_ids"] = schema.NewSet(schema.HashString, flattenStorageAccountVirtualNetworks(input.VirtualNetworkRules))
	networkRules["bypass"] = schema.NewSet(schema.HashString, flattenStorageAccountBypass(input.Bypass))
	networkRules["default_action"] = string(input.DefaultAction)

	return []interface{}{networkRules}
}
...
if d.HasChange("network_rules") {
...
}