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><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="DATATYPE-NET-TYPES"
>8.9. Network Address Types</A
></H1
><A
NAME="AEN6247"
></A
><P
>    <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> offers data types to store IPv4, IPv6, and MAC
    addresses, as shown in <A
HREF="datatype-net-types.html#DATATYPE-NET-TYPES-TABLE"
>Table 8-20</A
>.  It
    is better to use these types instead of plain text types to store
    network addresses, because
    these types offer input error checking and specialized
    operators and functions (see <A
HREF="functions-net.html"
>Section 9.12</A
>).
   </P
><DIV
CLASS="TABLE"
><A
NAME="DATATYPE-NET-TYPES-TABLE"
></A
><P
><B
>Table 8-20. Network Address Types</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><COL><COL><COL><THEAD
><TR
><TH
>Name</TH
><TH
>Storage Size</TH
><TH
>Description</TH
></TR
></THEAD
><TBODY
><TR
><TD
><TT
CLASS="TYPE"
>cidr</TT
></TD
><TD
>7 or 19 bytes</TD
><TD
>IPv4 and IPv6 networks</TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>inet</TT
></TD
><TD
>7 or 19 bytes</TD
><TD
>IPv4 and IPv6 hosts and networks</TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>macaddr</TT
></TD
><TD
>6 bytes</TD
><TD
>MAC addresses</TD
></TR
></TBODY
></TABLE
></DIV
><P
>    When sorting <TT
CLASS="TYPE"
>inet</TT
> or <TT
CLASS="TYPE"
>cidr</TT
> data types,
    IPv4 addresses will always sort before IPv6 addresses, including
    IPv4 addresses encapsulated or mapped to IPv6 addresses, such as
    ::10.2.3.4 or ::ffff:10.4.3.2.
   </P
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="DATATYPE-INET"
>8.9.1. <TT
CLASS="TYPE"
>inet</TT
></A
></H2
><A
NAME="AEN6284"
></A
><P
>     The <TT
CLASS="TYPE"
>inet</TT
> type holds an IPv4 or IPv6 host address, and
     optionally its subnet, all in one field.
     The subnet is represented by the number of network address bits
     present in the host address (the
     <SPAN
CLASS="QUOTE"
>"netmask"</SPAN
>).  If the netmask is 32 and the address is IPv4,
     then the value does not indicate a subnet, only a single host.
     In IPv6, the address length is 128 bits, so 128 bits specify a
     unique host address.  Note that if you
     want to accept only networks, you should use the
     <TT
CLASS="TYPE"
>cidr</TT
> type rather than <TT
CLASS="TYPE"
>inet</TT
>.
    </P
><P
>      The input format for this type is
      <TT
CLASS="REPLACEABLE"
><I
>address/y</I
></TT
>
      where
      <TT
CLASS="REPLACEABLE"
><I
>address</I
></TT
>
      is an IPv4 or IPv6 address and
      <TT
CLASS="REPLACEABLE"
><I
>y</I
></TT
>
      is the number of bits in the netmask.  If the
      <TT
CLASS="REPLACEABLE"
><I
>/y</I
></TT
>
      portion is missing, the
      netmask is 32 for IPv4 and 128 for IPv6, so the value represents
      just a single host.  On display, the
      <TT
CLASS="REPLACEABLE"
><I
>/y</I
></TT
>
      portion is suppressed if the netmask specifies a single host.
    </P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="DATATYPE-CIDR"
>8.9.2. <TT
CLASS="TYPE"
>cidr</TT
></A
></H2
><A
NAME="AEN6300"
></A
><P
>     The <TT
CLASS="TYPE"
>cidr</TT
> type holds an IPv4 or IPv6 network specification.
     Input and output formats follow Classless Internet Domain Routing
     conventions.
     The format for specifying networks is <TT
CLASS="REPLACEABLE"
><I
>address/y</I
></TT
> where <TT
CLASS="REPLACEABLE"
><I
>address</I
></TT
> is the network represented as an
     IPv4 or IPv6 address, and <TT
CLASS="REPLACEABLE"
><I
>y</I
></TT
> is the number of bits in the netmask.  If
     <TT
CLASS="REPLACEABLE"
><I
>y</I
></TT
> is omitted, it is calculated
     using assumptions from the older classful network numbering system, except
     it will be at least large enough to include all of the octets
     written in the input.  It is an error to specify a network address
     that has bits set to the right of the specified netmask.
    </P
><P
>     <A
HREF="datatype-net-types.html#DATATYPE-NET-CIDR-TABLE"
>Table 8-21</A
> shows some examples.
    </P
><DIV
CLASS="TABLE"
><A
NAME="DATATYPE-NET-CIDR-TABLE"
></A
><P
><B
>Table 8-21. <TT
CLASS="TYPE"
>cidr</TT
> Type Input Examples</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><COL><COL><COL><THEAD
><TR
><TH
><TT
CLASS="TYPE"
>cidr</TT
> Input</TH
><TH
><TT
CLASS="TYPE"
>cidr</TT
> Output</TH
><TH
><TT
CLASS="LITERAL"
><CODE
CLASS="FUNCTION"
>abbrev</CODE
>(<TT
CLASS="TYPE"
>cidr</TT
>)</TT
></TH
></TR
></THEAD
><TBODY
><TR
><TD
>192.168.100.128/25</TD
><TD
>192.168.100.128/25</TD
><TD
>192.168.100.128/25</TD
></TR
><TR
><TD
>192.168/24</TD
><TD
>192.168.0.0/24</TD
><TD
>192.168.0/24</TD
></TR
><TR
><TD
>192.168/25</TD
><TD
>192.168.0.0/25</TD
><TD
>192.168.0.0/25</TD
></TR
><TR
><TD
>192.168.1</TD
><TD
>192.168.1.0/24</TD
><TD
>192.168.1/24</TD
></TR
><TR
><TD
>192.168</TD
><TD
>192.168.0.0/24</TD
><TD
>192.168.0/24</TD
></TR
><TR
><TD
>128.1</TD
><TD
>128.1.0.0/16</TD
><TD
>128.1/16</TD
></TR
><TR
><TD
>128</TD
><TD
>128.0.0.0/16</TD
><TD
>128.0/16</TD
></TR
><TR
><TD
>128.1.2</TD
><TD
>128.1.2.0/24</TD
><TD
>128.1.2/24</TD
></TR
><TR
><TD
>10.1.2</TD
><TD
>10.1.2.0/24</TD
><TD
>10.1.2/24</TD
></TR
><TR
><TD
>10.1</TD
><TD
>10.1.0.0/16</TD
><TD
>10.1/16</TD
></TR
><TR
><TD
>10</TD
><TD
>10.0.0.0/8</TD
><TD
>10/8</TD
></TR
><TR
><TD
>10.1.2.3/32</TD
><TD
>10.1.2.3/32</TD
><TD
>10.1.2.3/32</TD
></TR
><TR
><TD
>2001:4f8:3:ba::/64</TD
><TD
>2001:4f8:3:ba::/64</TD
><TD
>2001:4f8:3:ba::/64</TD
></TR
><TR
><TD
>2001:4f8:3:ba:2e0:81ff:fe22:d1f1/128</TD
><TD
>2001:4f8:3:ba:2e0:81ff:fe22:d1f1/128</TD
><TD
>2001:4f8:3:ba:2e0:81ff:fe22:d1f1</TD
></TR
><TR
><TD
>::ffff:1.2.3.0/120</TD
><TD
>::ffff:1.2.3.0/120</TD
><TD
>::ffff:1.2.3/120</TD
></TR
><TR
><TD
>::ffff:1.2.3.0/128</TD
><TD
>::ffff:1.2.3.0/128</TD
><TD
>::ffff:1.2.3.0/128</TD
></TR
></TBODY
></TABLE
></DIV
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="DATATYPE-INET-VS-CIDR"
>8.9.3. <TT
CLASS="TYPE"
>inet</TT
> vs. <TT
CLASS="TYPE"
>cidr</TT
></A
></H2
><P
>    The essential difference between <TT
CLASS="TYPE"
>inet</TT
> and <TT
CLASS="TYPE"
>cidr</TT
>
    data types is that <TT
CLASS="TYPE"
>inet</TT
> accepts values with nonzero bits to
    the right of the netmask, whereas <TT
CLASS="TYPE"
>cidr</TT
> does not.
    </P
><DIV
CLASS="TIP"
><BLOCKQUOTE
CLASS="TIP"
><P
><B
>Tip: </B
>        If you do not like the output format for <TT
CLASS="TYPE"
>inet</TT
> or
        <TT
CLASS="TYPE"
>cidr</TT
> values, try the functions <CODE
CLASS="FUNCTION"
>host</CODE
>,
        <CODE
CLASS="FUNCTION"
>text</CODE
>, and <CODE
CLASS="FUNCTION"
>abbrev</CODE
>.
        </P
></BLOCKQUOTE
></DIV
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="DATATYPE-MACADDR"
>8.9.4. <TT
CLASS="TYPE"
>macaddr</TT
></A
></H2
><A
NAME="AEN6408"
></A
><A
NAME="AEN6410"
></A
><P
>     The <TT
CLASS="TYPE"
>macaddr</TT
> 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:

     <P
></P
><TABLE
BORDER="0"
><TBODY
><TR
><TD
><TT
CLASS="LITERAL"
>'08:00:2b:01:02:03'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>'08-00-2b-01-02-03'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>'08002b:010203'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>'08002b-010203'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>'0800.2b01.0203'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>'08002b010203'</TT
></TD
></TR
></TBODY
></TABLE
><P
></P
>

     These examples would all specify the same address.  Upper and
     lower case is accepted for the digits
     <TT
CLASS="LITERAL"
>a</TT
> through <TT
CLASS="LITERAL"
>f</TT
>.  Output is always in the
     first of the forms shown.
    </P
><P
>     IEEE Std 802-2001 specifies the second shown form (with hyphens)
     as the canonical form for MAC addresses, and specifies the first
     form (with colons) as the bit-reversed notation, so that
     08-00-2b-01-02-03 = 01:00:4D:08:04:0C.  This convention is widely
     ignored nowadays, and it is only relevant for obsolete network
     protocols (such as Token Ring).  PostgreSQL makes no provisions
     for bit reversal, and all accepted formats use the canonical LSB
     order.
    </P
><P
>     The remaining four input formats are not part of any standard.
    </P
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