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src/java.base/share/classes/java/net/InetAddress.java

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  55  * This class represents an Internet Protocol (IP) address.
  56  *
  57  * <p> An IP address is either a 32-bit or 128-bit unsigned number
  58  * used by IP, a lower-level protocol on which protocols like UDP and
  59  * TCP are built. The IP address architecture is defined by <a
  60  * href="http://www.ietf.org/rfc/rfc790.txt"><i>RFC&nbsp;790:
  61  * Assigned Numbers</i></a>, <a
  62  * href="http://www.ietf.org/rfc/rfc1918.txt"> <i>RFC&nbsp;1918:
  63  * Address Allocation for Private Internets</i></a>, <a
  64  * href="http://www.ietf.org/rfc/rfc2365.txt"><i>RFC&nbsp;2365:
  65  * Administratively Scoped IP Multicast</i></a>, and <a
  66  * href="http://www.ietf.org/rfc/rfc2373.txt"><i>RFC&nbsp;2373: IP
  67  * Version 6 Addressing Architecture</i></a>. An instance of an
  68  * InetAddress consists of an IP address and possibly its
  69  * corresponding host name (depending on whether it is constructed
  70  * with a host name or whether it has already done reverse host name
  71  * resolution).
  72  *
  73  * <h3> Address types </h3>
  74  *
  75  * <blockquote><table cellspacing=2 summary="Description of unicast and multicast address types">


  76  *   <tr><th valign=top><i>unicast</i></th>
  77  *       <td>An identifier for a single interface. A packet sent to
  78  *         a unicast address is delivered to the interface identified by
  79  *         that address.
  80  *
  81  *         <p> The Unspecified Address -- Also called anylocal or wildcard
  82  *         address. It must never be assigned to any node. It indicates the
  83  *         absence of an address. One example of its use is as the target of
  84  *         bind, which allows a server to accept a client connection on any
  85  *         interface, in case the server host has multiple interfaces.
  86  *
  87  *         <p> The <i>unspecified</i> address must not be used as
  88  *         the destination address of an IP packet.
  89  *
  90  *         <p> The <i>Loopback</i> Addresses -- This is the address
  91  *         assigned to the loopback interface. Anything sent to this
  92  *         IP address loops around and becomes IP input on the local
  93  *         host. This address is often used when testing a
  94  *         client.</td></tr>
  95  *   <tr><th valign=top><i>multicast</i></th>
  96  *       <td>An identifier for a set of interfaces (typically belonging
  97  *         to different nodes). A packet sent to a multicast address is
  98  *         delivered to all interfaces identified by that address.</td></tr>

  99  * </table></blockquote>
 100  *
 101  * <h4> IP address scope </h4>
 102  *
 103  * <p> <i>Link-local</i> addresses are designed to be used for addressing
 104  * on a single link for purposes such as auto-address configuration,
 105  * neighbor discovery, or when no routers are present.
 106  *
 107  * <p> <i>Site-local</i> addresses are designed to be used for addressing
 108  * inside of a site without the need for a global prefix.
 109  *
 110  * <p> <i>Global</i> addresses are unique across the internet.
 111  *
 112  * <h4> Textual representation of IP addresses </h4>
 113  *
 114  * The textual representation of an IP address is address family specific.
 115  *
 116  * <p>
 117  *
 118  * For IPv4 address format, please refer to <A




  55  * This class represents an Internet Protocol (IP) address.
  56  *
  57  * <p> An IP address is either a 32-bit or 128-bit unsigned number
  58  * used by IP, a lower-level protocol on which protocols like UDP and
  59  * TCP are built. The IP address architecture is defined by <a
  60  * href="http://www.ietf.org/rfc/rfc790.txt"><i>RFC&nbsp;790:
  61  * Assigned Numbers</i></a>, <a
  62  * href="http://www.ietf.org/rfc/rfc1918.txt"> <i>RFC&nbsp;1918:
  63  * Address Allocation for Private Internets</i></a>, <a
  64  * href="http://www.ietf.org/rfc/rfc2365.txt"><i>RFC&nbsp;2365:
  65  * Administratively Scoped IP Multicast</i></a>, and <a
  66  * href="http://www.ietf.org/rfc/rfc2373.txt"><i>RFC&nbsp;2373: IP
  67  * Version 6 Addressing Architecture</i></a>. An instance of an
  68  * InetAddress consists of an IP address and possibly its
  69  * corresponding host name (depending on whether it is constructed
  70  * with a host name or whether it has already done reverse host name
  71  * resolution).
  72  *
  73  * <h3> Address types </h3>
  74  *
  75  * <blockquote><table class="borderless">
  76  *   <caption style="display:none">Description of unicast and multicast address types</caption>
  77  *   <tbody>
  78  *   <tr><th valign=top><i>unicast</i></th>
  79  *       <td>An identifier for a single interface. A packet sent to
  80  *         a unicast address is delivered to the interface identified by
  81  *         that address.
  82  *
  83  *         <p> The Unspecified Address -- Also called anylocal or wildcard
  84  *         address. It must never be assigned to any node. It indicates the
  85  *         absence of an address. One example of its use is as the target of
  86  *         bind, which allows a server to accept a client connection on any
  87  *         interface, in case the server host has multiple interfaces.
  88  *
  89  *         <p> The <i>unspecified</i> address must not be used as
  90  *         the destination address of an IP packet.
  91  *
  92  *         <p> The <i>Loopback</i> Addresses -- This is the address
  93  *         assigned to the loopback interface. Anything sent to this
  94  *         IP address loops around and becomes IP input on the local
  95  *         host. This address is often used when testing a
  96  *         client.</td></tr>
  97  *   <tr><th valign=top><i>multicast</i></th>
  98  *       <td>An identifier for a set of interfaces (typically belonging
  99  *         to different nodes). A packet sent to a multicast address is
 100  *         delivered to all interfaces identified by that address.</td></tr>
 101  * </tbody>
 102  * </table></blockquote>
 103  *
 104  * <h4> IP address scope </h4>
 105  *
 106  * <p> <i>Link-local</i> addresses are designed to be used for addressing
 107  * on a single link for purposes such as auto-address configuration,
 108  * neighbor discovery, or when no routers are present.
 109  *
 110  * <p> <i>Site-local</i> addresses are designed to be used for addressing
 111  * inside of a site without the need for a global prefix.
 112  *
 113  * <p> <i>Global</i> addresses are unique across the internet.
 114  *
 115  * <h4> Textual representation of IP addresses </h4>
 116  *
 117  * The textual representation of an IP address is address family specific.
 118  *
 119  * <p>
 120  *
 121  * For IPv4 address format, please refer to <A


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