// 6 is the magical number for inbound: 15006, 127.0.0.6, ::6
	InboundPassthroughBindIpv4 = "127.0.0.6"
	InboundPassthroughBindIpv6 = "::6"
)

var (
	// maintain 3 maps to return wildCards, localHosts and passthroughBindIPs according to IP mode of proxy
	wildCards = map[model.IPMode][]string{
		model.IPv4: {WildcardAddress},
		model.IPv6: {WildcardIPv6Address},
		model.Dual: {WildcardAddress, WildcardIPv6Address},
	}

		// more than one IP for the proxy.
		if features.EnableDualStack && len(cb.passThroughBindIPs) > 1 {
			// add extra source addresses to cluster builder
			var extraSrcAddrs []*core.ExtraSourceAddress
			for _, extraBdIP := range cb.passThroughBindIPs[1:] {
				extraSrcAddr := &core.ExtraSourceAddress{
					Address: &core.SocketAddress{
						Address: extraBdIP,