if len(clusterCIDRs) == 0 {
			return nil, fmt.Errorf("Controller: Must specify --cluster-cidr if --allocate-node-cidrs is set")
		}

		for idx, cidr := range clusterCIDRs {
			mask := cidr.Mask
			if maskSize, _ := mask.Size(); maskSize > nodeCIDRMaskSizes[idx] {
				return nil, fmt.Errorf("Controller: Invalid --cluster-cidr, mask size of cluster CIDR must be less than or equal to --node-cidr-mask-size configured for CIDR family")
			}
		}
	}