* 2. IPv4: api-server will assign an IP from a `service-cluster-ip-range` that is `ipv4` (either the primary or the secondary, according to how they were configured).
    * 2. IPv6: api-server will assign an IP from a `service-cluster-ip-range` that is `ipv6` (either the primary or the secondary, according to how they were configured).
    * Notes (v1.16):
    * 1. IPVS is the only proxy supported (as of v1.16 ) by Dualstack.

- File content check for IPV4 is now enabled by default, and the check of IPV4 or IPV6 is done for `kubeadm init` or `kubeadm join` only in case the user intends to create a cluster to support that kind of IP address family ([#115420](https://github.com/kubernetes/kubernetes/pull/115420), [@chendave](http...

      - [Multi-platform](#multi-platform)
      - [Cloud Providers](#cloud-providers)
    - [Network](#network)
      - [network-policy](#network-policy)
      - [kube-proxy ipvs mode](#kube-proxy-ipvs-mode)
    - [API Machinery](#api-machinery)
      - [kube-apiserver](#kube-apiserver)
      - [Dynamic Admission Control](#dynamic-admission-control)

  This is putting cgroup v1 into a deprecated state. ([#134298](https://github.com/kubernetes/kubernetes/pull/134298), [@kannon92](https://github.com/kannon92)) [SIG Node]

 *   <dt>An IPv6 "IPv4 mapped" address, {@code "::ffff:192.168.0.1"}.
 *   <dd>{@code 00 00 00 00 00 00 00 00 00 00 ff ff c0 a8 00 01}
 * </dl>
 *
 * <p>A few notes about IPv6 "IPv4 mapped" addresses and their observed use in Java.
 *
 * <p>"IPv4 mapped" addresses were originally a representation of IPv4 addresses for use on an IPv6
 * socket that could receive both IPv4 and IPv6 connections (by disabling the {@code IPV6_V6ONLY}

    }

    @Test
    void testAddIPAddresses() throws Exception {
        InetAddress ipv4 = InetAddress.getByName("192.168.1.100");
        InetAddress ipv6 = InetAddress.getByName("2001:db8::1");

        notification.addNewIPAddress(ipv4);
        notification.addNewIPAddress(ipv6);
        notification.addOldIPAddress(ipv4);

        List<WitnessNotification.WitnessIPAddress> newAddresses = notification.getNewIPAddresses();

    val request = Request(server1.url("/"))

    server1.enqueue(refusedStream)
    server2.enqueue(bodyResponse)

    dns[server1.hostName] = listOf(ipv6, ipv4)
    socketFactory[ipv6] = server1.socketAddress
    socketFactory[ipv4] = server2.socketAddress

    client =
      client
        .newBuilder()
        .fastFallback(false)
        .apply {
          retryOnConnectionFailure = false

internal fun reorderForHappyEyeballs(addresses: List<InetAddress>): List<InetAddress> {
  if (addresses.size < 2) {
    return addresses
  }

  val (ipv6, ipv4) = addresses.partition { it is Inet6Address }

  return if (ipv6.isEmpty() || ipv4.isEmpty()) {
    addresses
  } else {
    interleave(ipv6, ipv4)
  }

 *   <dt>An IPv6 "IPv4 mapped" address, {@code "::ffff:192.168.0.1"}.
 *   <dd>{@code 00 00 00 00 00 00 00 00 00 00 ff ff c0 a8 00 01}
 * </dl>
 *
 * <p>A few notes about IPv6 "IPv4 mapped" addresses and their observed use in Java.
 *
 * <p>"IPv4 mapped" addresses were originally a representation of IPv4 addresses for use on an IPv6
 * socket that could receive both IPv4 and IPv6 connections (by disabling the {@code IPV6_V6ONLY}

import org.junitpioneer.jupiter.RetryingTest
import org.opentest4j.TestAbortedException

/**
 * This test binds two different web servers (IPv4 and IPv6) to the same port, but on different
 * local IP addresses. Requests made to `127.0.0.1` will reach the IPv4 server, and requests made to
 * `::1` will reach the IPv6 server.
 *
 * By orchestrating two different servers with the same port but different IP addresses, we can