inet(7)                             CLIX                             inet(7)



  NAME

    inet - Internet protocol family

  SYNOPSIS

    #include <sys/types.h>

    #include <netinet/in.h>

  DESCRIPTION

    The Internet protocol family is a collection of protocols layered on top
    of the Internet Protocol (IP) transport layer using the Internet address
    format.  The Internet family provides protocol support for the sock_stream
    and sock_dgram socket types.

    Internet addresses are four-byte quantities, stored in network standard
    format.  (The CLIPPER standard representation of a 32-bit quantity is
    short-word and byte reversed from network order.)  The include file
    <netinet/in.h> defines this address as a discriminated union.

    Sockets bound to the Internet protocol family use the following addressing
    structure:

    struct sockaddr_in {
         short   sin_family;
         u_short sin_port;
         struct  in_addr sin_addr;
         char    sin_zero[8];
    };

    Sockets may be created with the local address INADDR_ANY to effect
    ``wildcard'' matching on incoming messages.  The address in a connect() or
    sendto() function may be given as INADDR_ANY to mean ``this host.''  The
    distinguished address INADDR_BROADCAST is allowed as a shorthand for the
    broadcast address on the primary network if the first network configured
    supports broadcast.

    The Internet protocol family is comprised of the IP transport protocol,
    Internet Control Message Protocol (ICMP), Transmission Control Protocol
    (TCP), and User Datagram Protocol (UDP).  TCP is used to support the
    sock_stream abstraction while UDP is used to support the sock_dgram
    abstraction.  IP and ICMP are not currently supported.

    The 32-bit Internet address contains both network and host parts.  It is
    frequency-encoded; the most-significant bit is clear in Class A addresses,
    in which the high-order 8 bits are the network number.  Class B addresses
    use the high-order 16 bits as the network field, and Class C addresses
    have a 24-bit network part.  Sites with a cluster of local networks and a
    connection to the Defense Advanced Research Project Agency (DARPA)



  2/94 - Intergraph Corporation                                              1

  inet(7)                             CLIX                             inet(7)



    Internet may choose to use a single network number for the cluster; this
    is done by using subnet addressing.  The local (host) portion of the
    address is further subdivided into subnet and host parts.  Within a
    subnet, each subnet appears to be an individual network; externally, the
    entire cluster appears to be a single, uniform network requiring only a
    single routing entry.

  NOTES

    The Internet protocol support is subject to change as the Internet
    protocols develop.  Users should not depend on details of the current
    implementation, but rather the services exported.

  RELATED INFORMATION

    Functions:  socket(2)

    Files:  intro(7), tcp(7), udp(7)

    CLIX Programming Guide


































  2                                              Intergraph Corporation - 2/94