<entry>2001:4f8:3:ba:&zwsp;2e0:81ff:fe22:d1f1/128</entry>
         <entry>2001:4f8:3:ba:&zwsp;2e0:81ff:fe22:d1f1/128</entry>
         <entry>2001:4f8:3:ba:&zwsp;2e0:81ff:fe22:d1f1/128</entry>
        </row>
        <row>
         <entry>::ffff:1.2.3.0/120</entry>
         <entry>::ffff:1.2.3.0/120</entry>
         <entry>::ffff:1.2.3/120</entry>
        </row>
        <row>
         <entry>::ffff:1.2.3.0/128</entry>
         <entry>::ffff:1.2.3.0/128</entry>
         <entry>::ffff:1.2.3.0/128</entry>
        </row>
       </tbody>
      </tgroup>
     </table>
   </sect2>

   <sect2 id="datatype-inet-vs-cidr">
    <title><type>inet</type> vs. <type>cidr</type></title>

    <para>
    The essential difference between <type>inet</type> and <type>cidr</type>
    data types is that <type>inet</type> accepts values with nonzero bits to
    the right of the netmask, whereas <type>cidr</type> does not.  For
    example, <literal>192.168.0.1/24</literal> is valid for <type>inet</type>
    but not for <type>cidr</type>.
    </para>

      <tip>
        <para>
        If you do not like the output format for <type>inet</type> or
        <type>cidr</type> values, try the functions <function>host</function>,
        <function>text</function>, and <function>abbrev</function>.
        </para>
      </tip>
   </sect2>

   <sect2 id="datatype-macaddr">
    <title><type>macaddr</type></title>

    <indexterm>
     <primary>macaddr (data type)</primary>
    </indexterm>

    <indexterm>
     <primary>MAC address</primary>
     <see>macaddr</see>
    </indexterm>

    <para>
     The <type>macaddr</type> type stores MAC addresses, known for example
     from Ethernet card hardware addresses (although MAC addresses are
     used for other purposes as well).  Input is accepted in the
     following formats:

     <simplelist>
      <member><literal>'08:00:2b:01:02:03'</literal></member>
      <member><literal>'08-00-2b-01-02-03'</literal></member>
      <member><literal>'08002b:010203'</literal></member>
      <member><literal>'08002b-010203'</literal></member>
      <member><literal>'0800.2b01.0203'</literal></member>
      <member><literal>'0800-2b01-0203'</literal></member>
      <member><literal>'08002b010203'</literal></member>
     </simplelist>

     These examples all specify the same address.  Upper and
     lower case is accepted for the digits
     <literal>a</literal> through <literal>f</literal>.  Output is always in the
     first of the forms shown.
    </para>

    <para>
     IEEE Standard 802-2001 specifies the second form shown (with hyphens)
     as the canonical form for MAC addresses, and specifies the first
     form (with colons) as used with bit-reversed, MSB-first notation, so that
     08-00-2b-01-02-03 = 10:00:D4:80:40:C0.  This convention is widely
     ignored nowadays, and it is relevant only for obsolete network
     protocols (such as Token Ring).  PostgreSQL makes no provisions
     for bit reversal; all accepted formats use the canonical LSB
     order.
    </para>

    <para>
     The remaining five input formats are not part of any standard.
    </para>
   </sect2>

   <sect2 id="datatype-macaddr8">
    <title><type>macaddr8</type></title>

    <indexterm>
     <primary>macaddr8 (data type)</primary>
    </indexterm>

    <indexterm>
     <primary>MAC address (EUI-64 format)</primary>
     <see>macaddr</see>
    </indexterm>

    <para>
     The <type>macaddr8</type> type stores MAC addresses in EUI-64
     format, known for example from Ethernet card hardware addresses
     (although MAC addresses are used for other purposes as well).
     This type can accept both 6 and 8 byte length MAC addresses
     and stores them in 8 byte length format.  MAC addresses given
     in 6 byte format will be stored in 8 byte length format with the
     4th and 5th bytes set to FF and FE, respectively.

     Note that IPv6 uses a modified EUI-64 format where the 7th bit
     should be set to one after the conversion from EUI-48.