Name: dfR10049 Date: 01/16/2001



java.net.Inet6Address.getHostAddress() states:

  "Returns the IP address string in standard text presentation form"

But there is no specification for "standard text presentation form"

rfc2373(IP Version 6 Addressing Architecture) allows to use 4 forms of
text presentation of IPV6 addresses.
For example, the next four strings are equivalent presentation of the same address:

1080:0:0:0:0:800:200C:417A
1080::800:200C:417A
1080:0:0:0:0:800:32.13.65.122
1080::800:32.13.65.122

No one of these forms is called "standard form". So javadoc should specify
the format or several formats can be used for the IPV6 addresses representation.

Please find a part of rfc2373 below:

2.2 Text Representation of Addresses

   There are three conventional forms for representing IPv6 addresses as
   text strings:

   1. The preferred form is x:x:x:x:x:x:x:x, where the 'x's are the
      hexadecimal values of the eight 16-bit pieces of the address.
      Examples:

         FEDC:BA98:7654:3210:FEDC:BA98:7654:3210

         1080:0:0:0:8:800:200C:417A

      Note that it is not necessary to write the leading zeros in an
      individual field, but there must be at least one numeral in every
      field (except for the case described in 2.).

   2. Due to some methods of allocating certain styles of IPv6
      addresses, it will be common for addresses to contain long strings
      of zero bits. In order to make writing addresses containing zero
      bits easier a special syntax is available to compress the zeros.
      The use of "::" indicates multiple groups of 16-bits of zeros.
      The "::" can only appear once in an address. The "::" can also be
      used to compress the leading and/or trailing zeros in an address.

      For example the following addresses:

         1080:0:0:0:8:800:200C:417A a unicast address
         FF01:0:0:0:0:0:0:101 a multicast address
         0:0:0:0:0:0:0:1 the loopback address
         0:0:0:0:0:0:0:0 the unspecified addresses

      may be represented as:

         1080::8:800:200C:417A a unicast address
         FF01::101 a multicast address
         ::1 the loopback address
         :: the unspecified addresses

   3. An alternative form that is sometimes more convenient when dealing
      with a mixed environment of IPv4 and IPv6 nodes is
      x:x:x:x:x:x:d.d.d.d, where the 'x's are the hexadecimal values of
      the six high-order 16-bit pieces of the address, and the 'd's are
      the decimal values of the four low-order 8-bit pieces of the
      address (standard IPv4 representation). Examples:

         0:0:0:0:0:0:13.1.68.3

         0:0:0:0:0:FFFF:129.144.52.38

      or in compressed form:

         ::13.1.68.3

         ::FFFF:129.144.52.38


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