addrs, err := net.InterfaceAddrs()
	if err != nil {
		t.Fatalf("%s.  Unable to get IP addresses of this host.", err)
	}

	for _, addr := range addrs {
		var ip net.IP
		switch v := addr.(type) {
		case *net.IPNet:
			ip = v.IP
		case *net.IPAddr:
			ip = v.IP
		}

		if ip.To4() != nil {
			localIP4.Add(ip.String())
		}
	}

	// Filter ipList by IPs those do not start with '127.'.

	}

	for _, wl := range verifiedWorkloads {
		var ip string
		if len(wl.WorkloadIPs) > 0 {
			ip = wl.WorkloadIPs[0]
		}
		if filter.Verbose {
			waypoint := waypointName(wl, zDump.Services)
			fmt.Fprintf(w, "%v\t%v\t%v\t%v\t%v\t%v\n",
				wl.Namespace, wl.Name, ip, wl.Node, waypoint, wl.Protocol)
		} else {
			fmt.Fprintf(w, "%v\t%v\t%v\t%v\n", wl.Namespace, wl.Name, ip, wl.Node)
		}
	}
	return w.Flush()
}

	ipsetIPHashCreate(name string, v6 bool) error
	destroySet(name string) error
	addIP(name string, ip netip.Addr, ipProto uint8, comment string, replace bool) error
	deleteIP(name string, ip netip.Addr, ipProto uint8) error
	flush(name string) error
	clearEntriesWithComment(name string, comment string) error
	clearEntriesWithIP(name string, ip netip.Addr) error
	listEntriesByIP(name string) ([]netip.Addr, error)
}

	for _, configuredPodIPs := range addCmd.IPs {
		// net.ip is implicitly convertible to netip as slice
		ip, _ := netip.AddrFromSlice(configuredPodIPs.Address.IP)
		// We ignore the mask of the IPNet - it's fine if the IPNet defines
		// a block grant of addresses, we just need one for checking routes.
		podIps = append(podIps, ip)
	}

  * In Istio sidecars, historically we had a lot of client-specific xDS. For example, putting the xDS-client's IP back into the xDS response. This makes efficient control plane implementation (most notably, caching), extremely challenging.
  * In practice, this largely means that references are fully qualified in the API. IP Addresses (generally) have a network associated with them, node names have a cluster associated with them, etc.

    /**
     * Check whether a hostname is actually an ip address
     * 
     * @param hostname
     * @return whether this is an IP address
     */
    public static boolean isDotQuadIP ( String hostname ) {
        if ( Character.isDigit(hostname.charAt(0)) ) {
            int i, len, dots;
            char[] data;

            i = dots = 0; /* quick IP address validation */
            len = hostname.length();

	HostProbeSNATIP   = netip.MustParseAddr(env.RegisterStringVar("HOST_PROBE_SNAT_IP", DefaultHostProbeSNATIP, "").Get())
	HostProbeSNATIPV6 = netip.MustParseAddr(env.RegisterStringVar("HOST_PROBE_SNAT_IPV6", DefaultHostProbeSNATIPV6, "").Get())
)

const (
	// to reliably identify kubelet healthprobes from inside the pod (versus standard kube-proxy traffic,
	// since the IP is normally the same), we SNAT identified host probes in the host netns to a fixed

	for netIP, s := range d.Services {
		_, ip, _ := strings.Cut(netIP, "/")
		serviceNames[ip] = s.Hostname
	}
	for netIP, s := range d.Workloads {
		_, ip, _ := strings.Cut(netIP, "/")
		workloadNames[ip] = s.Name + "." + s.Namespace
	}
	lookupIP := func(addr string) string {
		if filter.Raw {
			return addr
		}
		ip, port, _ := net.SplitHostPort(addr)
		if s, f := serviceNames[ip]; f {
			return net.JoinHostPort(s, port)
		}

### DNS

Теперь давайте сфокусируемся на работе с HTTPS.

Всё начинается с того, что браузер спрашивает у **DNS-серверов**, какой **IP-адрес связан с доменом**, для примера возьмём домен `someapp.example.com`.

DNS-сервера присылают браузеру определённый **IP-адрес**, тот самый публичный IP-адрес вашего сервера, который вы указали в ресурсной "записи А" при настройке.

            proxy_set_header Host $http_host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
            proxy_set_header X-NginX-Proxy true;

            # This is necessary to pass the correct IP to be hashed
            real_ip_header X-Real-IP;

            proxy_connect_timeout 300;