* element content or {@link #xmlAttributeEscaper} in attribute values.
   *
   * <p>This escaper substitutes {@code 0xFFFD} for non-whitespace control characters and the
   * character values {@code 0xFFFE} and {@code 0xFFFF} which are not permitted in XML. For more
   * detail see section <a href="http://www.w3.org/TR/2008/REC-xml-20081126/#charsets">2.2</a> of
   * the XML specification.
   *

      <match value="0xfff2" type="string" offset="0"/> <!-- V2, L3, CRC -->
      <match value="0xfff3" type="string" offset="0"/> <!-- V2, L3      -->
      <match value="0xfff4" type="string" offset="0"/> <!-- V2, L2, CRC -->
      <match value="0xfff5" type="string" offset="0"/> <!-- V2, L2      -->
      <match value="0xfff6" type="string" offset="0"/> <!-- V2, L1, CRC -->

-A PREROUTING -j ISTIO_PRERT
-A OUTPUT -j ISTIO_OUTPUT
-A ISTIO_PRERT -m mark --mark 0x539/0xfff -j CONNMARK --set-xmark 0x111/0xfff
-A ISTIO_PRERT -s 169.254.7.127 -p tcp -m tcp -j ACCEPT
-A ISTIO_PRERT ! -d 127.0.0.1/32 -p tcp -i lo -j ACCEPT
-A ISTIO_PRERT -p tcp -m tcp --dport 15008 -m mark ! --mark 0x539/0xfff -j TPROXY --on-port 15008 --tproxy-mark 0x111/0xfff
-A ISTIO_PRERT -p tcp -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT

-A ISTIO_PRERT ! -d 127.0.0.1/32 -p tcp ! --dport 15008 -m mark ! --mark 0x539/0xfff -j REDIRECT --to-ports 15006
-A ISTIO_OUTPUT ! -o lo -p udp -m mark ! --mark 0x539/0xfff -m udp --dport 53 -j REDIRECT --to-port 15053
-A ISTIO_OUTPUT ! -d 127.0.0.1/32 -p tcp --dport 53 -m mark ! --mark 0x539/0xfff -j REDIRECT --to-ports 15053
-A ISTIO_OUTPUT -p tcp -m mark --mark 0x111/0xfff -j ACCEPT
-A ISTIO_OUTPUT ! -d 127.0.0.1/32 -o lo -j ACCEPT

    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

-A OUTPUT -j ISTIO_OUTPUT
-A ISTIO_OUTPUT -m connmark --mark 0x111/0xfff -j CONNMARK --restore-mark --nfmask 0xffffffff --ctmask 0xffffffff
COMMIT
* nat
-N ISTIO_OUTPUT
-N ISTIO_PRERT
-A OUTPUT -j ISTIO_OUTPUT
-A PREROUTING -j ISTIO_PRERT
-A ISTIO_OUTPUT -d 169.254.7.127 -p tcp -m tcp -j ACCEPT
-A ISTIO_OUTPUT -p tcp -m mark --mark 0x111/0xfff -j ACCEPT
-A ISTIO_OUTPUT ! -d 127.0.0.1/32 -o lo -j ACCEPT

      checkArgument(
          (port >= 0) && (port <= 0xffff), "port '%s' is out of range (0 <= port <= 0xffff)", port);
      checkArgument(
          (flags >= 0) && (flags <= 0xffff),
          "flags '%s' is out of range (0 <= flags <= 0xffff)",
          flags);

      this.server = MoreObjects.firstNonNull(server, ANY4);

-A ISTIO_PRERT -p tcp -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A ISTIO_PRERT ! -d ::1/128 -p tcp -m mark ! --mark 0x539/0xfff -j TPROXY --on-port 15006 --tproxy-mark 0x111/0xfff
-A ISTIO_OUTPUT -m connmark --mark 0x111/0xfff -j CONNMARK --restore-mark --nfmask 0xffffffff --ctmask 0xffffffff
COMMIT
* nat
-N ISTIO_OUTPUT
-A OUTPUT -j ISTIO_OUTPUT

-A ISTIO_PRERT ! -d 127.0.0.1/32 -p tcp ! --dport 15008 -m mark ! --mark 0x539/0xfff -j REDIRECT --to-ports 15006
-A ISTIO_OUTPUT ! -o lo -p udp -m mark ! --mark 0x539/0xfff -m udp --dport 53 -j REDIRECT --to-port 15053
-A ISTIO_OUTPUT ! -d 127.0.0.1/32 -p tcp --dport 53 -m mark ! --mark 0x539/0xfff -j REDIRECT --to-ports 15053
-A ISTIO_OUTPUT -p tcp -m mark --mark 0x111/0xfff -j ACCEPT
-A ISTIO_OUTPUT ! -d 127.0.0.1/32 -o lo -j ACCEPT

-A OUTPUT -j ISTIO_OUTPUT
-A ISTIO_OUTPUT -m connmark --mark 0x111/0xfff -j CONNMARK --restore-mark --nfmask 0xffffffff --ctmask 0xffffffff
COMMIT
* nat
-N ISTIO_OUTPUT
-N ISTIO_PRERT
-A OUTPUT -j ISTIO_OUTPUT
-A PREROUTING -j ISTIO_PRERT
-A ISTIO_OUTPUT -d 169.254.7.127 -p tcp -m tcp -j ACCEPT
-A ISTIO_OUTPUT -p tcp -m mark --mark 0x111/0xfff -j ACCEPT
-A ISTIO_OUTPUT ! -d 127.0.0.1/32 -o lo -j ACCEPT