if unwrapAddr.Is4() {
			break
		}
	}
	log.Infof("Addr resolved to: %s", resolvedAddr)
	return resolvedAddr, nil
}

// AllIPv6 checks the addresses slice and returns true if all addresses
// are valid IPv6 address, for all other cases it returns false.
func AllIPv6(ipAddrs []string) bool {
	for i := 0; i < len(ipAddrs); i++ {
		addr, err := netip.ParseAddr(ipAddrs[i])
		if err != nil {

			expected: false,
		},
		{
			name:     "test for invalid ip address",
			addrs:    []string{"invalidip"},
			expected: true,
		},
	}
	for _, tt := range tests {
		result := AllIPv6(tt.addrs)
		if result != tt.expected {
			t.Errorf("Test %s failed, expected: %t got: %t", tt.name, tt.expected, result)
		}
	}
}

func TestAllIPv4(t *testing.T) {
	tests := []struct {

func (e *envoy) UpdateConfig(config []byte) error {
	return os.WriteFile(e.ConfigPath, config, 0o666)
}

func (e *envoy) args(fname string, overrideFname string) []string {
	proxyLocalAddressType := "v4"
	if network.AllIPv6(e.NodeIPs) {
		proxyLocalAddressType = "v6"
	}
	startupArgs := []string{
		"-c", fname,
		"--drain-time-s", fmt.Sprint(int(e.DrainDuration.AsDuration().Seconds())),

const (
	IPv4 IPMode = iota + 1
	IPv6
	Dual
)

func DiscoverIPMode(addrs []string) IPMode {
	if networkutil.AllIPv4(addrs) {
		return IPv4
	} else if networkutil.AllIPv6(addrs) {
		return IPv6
	}
	return Dual

		// IPv4 only
		opts = append(opts,
			option.Localhost(option.LocalhostIPv4),
			option.Wildcard(option.WildcardIPv4),
			option.DNSLookupFamily(option.DNSLookupFamilyIPv4))
	} else if network.AllIPv6(cfg.Metadata.InstanceIPs) {
		// IPv6 only
		opts = append(opts,
			option.Localhost(option.LocalhostIPv6),
			option.Wildcard(option.WildcardIPv6),
			option.DNSLookupFamily(option.DNSLookupFamilyIPv6))
	} else {

	case cluster.Cluster_STRICT_DNS, cluster.Cluster_LOGICAL_DNS:
		if networkutil.AllIPv4(cb.proxyIPAddresses) {
			// IPv4 only
			c.DnsLookupFamily = cluster.Cluster_V4_ONLY
		} else if networkutil.AllIPv6(cb.proxyIPAddresses) {
			// IPv6 only
			c.DnsLookupFamily = cluster.Cluster_V6_ONLY
		} else {
			// Dual Stack
			if features.EnableDualStack {