val flags = buf.readShort().toInt() and 0xffff
    require(flags shr 15 != 0) { "not a response" }

    val responseCode = flags and 0xf

    if (responseCode == NXDOMAIN) {
      throw UnknownHostException("$hostname: NXDOMAIN")
    } else if (responseCode == SERVFAIL) {
      throw UnknownHostException("$hostname: SERVFAIL")
    }

    val questionCount = buf.readShort().toInt() and 0xffff

              "74c01b5adb12c100000e10000003840012750000000e10"
          ).decodeHex(),
      )
    }.also { expected ->
      assertThat(expected.message).isEqualTo("sdflkhfsdlkjdf.ee: NXDOMAIN")
    }
  }

      ),
    )
    try {
      dns.lookup("google.com")
      fail<Any>()
    } catch (uhe: UnknownHostException) {
      assertThat(uhe.message).isEqualTo("google.com: NXDOMAIN")
    }
    val recordedRequest = server.takeRequest()
    assertThat(recordedRequest.method).isEqualTo("GET")
    assertThat(recordedRequest.path)

  # to work in an offline environment:
  # https://github.com/coredns/coredns/issues/2494#issuecomment-457215452
  # CoreDNS should handle those domains and answer with NXDOMAIN instead of SERVFAIL
  # otherwise pods stops trying to resolve the domain.
  if [ "${IP_FAMILY}" = "ipv6" ] || [ "${IP_FAMILY}" = "dual" ]; then
    # Get the current config

* Add --no-negcache flag to kube-dns to prevent caching of NXDOMAIN responses. ([#66036](https://github.com/kubernetes/kubernetes/pull/66036), [@prameshj](https://github.com/prameshj))