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File Formats                                         netconfig(4)

     netconfig - network configuration database


     The network configuration database,   /etc/netconfig,  is  a
     system  file  used  to store information about networks that
     are connected to the system. The  netconfig database and the
     routines  that  access it (see  getnetconfig(3NSL)) are part
     of the Network Selection component.  The  Network  Selection
     component also includes getnetpath(3NSL) routines to provide
     application-specific network search  paths.  These  routines
     access  the   netconfig  database  based  on the environment
     variable NETPATH. See environ(5).

     netconfig contains an entry for each  network  available  on
     the  system.  Entries  are separated by newlines. Fields are
     separated by whitespace and occur in the order in which they
     are   described   below.   Whitespace  can  be  embedded  as
     ``\fRblank'' or ``\fRtab''. Backslashes may be  embedded  as
     ``\''. Lines in /etc/netconfig that begin with a # (hash) in
     column 1 are treated as comments.

     Each of the valid lines in the netconfig database correspond
     to an available transport. Each entry is of the form:

      network ID  semantics  flag  protocol-family
      protocol-name   network-device  translation-libraries

     network ID
           A string used to uniquely identify a network.  network
           ID  consists  of non-null characters, and has a length
           of at least 1. No maximum length  is  specified.  This
           namespace  is locally significant and the local system
           administrator is the naming  authority.  All   network
           IDs on a system must be unique.

           The  semantics  field  is  a  string  identifying  the
           ``semantics'' of the network, that is, the set of ser-
           vices it supports, by identifying the  service  inter-
           face  it  provides. The  semantics field is mandatory.
           The following semantics are recognized.

                 Transport Provider Interface, connectionless

                 Transport   Provider    Interface,    connection

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File Formats                                         netconfig(4)


                 Transport   Provider    Interface,    connection
                 oriented, supports  orderly release.

     flag  The  flag field records certain  two-valued  (``true''
           and  ``false'')  attributes  of  networks.  flag  is a
           string composed of a combination of  characters,  each
           of  which  indicates  the  value  of the corresponding
           attribute. If the character is present, the  attribute
           is ``true.'' If the character is absent, the attribute
           is ``false.'' ``-'' indicates that none of the  attri-
           butes  are  present.   Only one character is currently

           v     Visible (``default'')  network.  Used  when  the
                 environment variable  NETPATH is unset.

     protocol family
           The  protocol family and   protocol  name  fields  are
           provided   for  protocol-specific  applications.   The
           protocol family field contains a string  that  identi-
           fies  a protocol family. The  protocol family identif-
           ier follows the same rules as those for  network  IDs;
           the  string  consists of non-null characters, it has a
           length of at least 1, and there is no  maximum  length
           specified. A ``-'' in the  protocol family field indi-
           cates that no protocol family identifier applies  (the
           network is experimental).  The following are examples:

                 Loopback (local to host).

           inet  Internetwork:  UDP, TCP, and the like.

           inet6 Internetwork over IPv6: UDP, TCP, and the like.

                 ARPANET imp addresses

           pup   PUP protocols:  for example, BSP

           chaos MIT CHAOS protocols

           ns    XEROX NS protocols

           nbs   NBS protocols

           ecma  European Computer Manufacturers Association

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File Formats                                         netconfig(4)

                 DATAKIT protocols

           ccitt CCITT protocols, X.25, and the like.

           sna   IBM SNA


           dli   Direct data link interface

           lat   LAT

                 NSC Hyperchannel

                 Apple Talk

           nit   Network Interface Tap

                 IEEE 802.2; also ISO 8802

           osi   Umbrella for all families used by OSI (for exam-
                 ple, protosw lookup)

           x25   CCITT X.25 in particular

                 AFI = 47, IDI = 4

           gosip U.S. Government OSI

     protocol name
           The  protocol name field contains a string that  iden-
           tifies  a protocol. The  protocol name identifier fol-
           lows the same rules as those for network IDs; that is,
           the  string  consists of non-NULL characters, it has a
           length of at least 1, and there is no  maximum  length
           specified.  A  ``-''  indicates that none of the names
           listed apply. The following protocol names are  recog-

           tcp   Transmission Control Protocol

           udp   User Datagram Protocol

           icmp  Internet Control Message Protocol

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File Formats                                         netconfig(4)

     network device
           The  network device is the full pathname of the device
           used  to connect to the transport provider. Typically,
           this device will be in the /dev directory.  The   net-
           work device must be specified.

     translation libraries
           The  name-to-address translation libraries  support  a
           ``directory  service'' (a name-to-address mapping ser-
           vice) for the network. A ``-'' in this field indicates
           the  absence of any  translation libraries. This has a
           special meaning for networks of  the  protocol  family
           inet  : its name-to-address mapping is provided by the
           name service switch based on the entries for hosts and
           services  in  nsswitch.conf(4).  For networks of other
           families, a ``-''  indicates  non-functional  name-to-
           address  mapping.  Otherwise, this field consists of a
           comma-separated  list  of  pathnames  to   dynamically
           linked  libraries.  The pathname of the library can be
           either absolute or relative. See dlopen(3DL).

     Each field corresponds to an element in the struct netconfig
     structure. struct netconfig and the identifiers described on
     this manual page are defined in <netconfig.h>.  This  struc-
     ture includes the following members:

          char *nc_netid
                Network ID, including  NULL terminator.

          unsigned long nc_semantics

          unsigned long nc_flag

          char *nc_protofmly
                Protocol family.

          char *nc_proto
                Protocol name.

          char *nc_device
                Full pathname of the network device.

          unsigned long nc_nlookups
                Number of directory lookup libraries.

          char **nc_lookups
                Names   of   the   name-to-address    translation

          unsigned long nc_unused[9]

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File Formats                                         netconfig(4)

                Reserved for future expansion.

     The   nc_semantics  field  takes   the   following   values,
     corresponding to the semantics identified above:



               NC_TPI_COTS_ORD The  nc_flag field is a  bitfield.
               The  following bit, corresponding to the attribute
               identified   above,   is   currently   recognized.
               NC_NOFLAG indicates the absence of any attributes.


     Example 1: A Sample netconfig File

     Below is a sample netconfig file:

     #  The "Network Configuration" File.
     # Each entry is of the form:
     #   <networkid> <semantics> <flags> <protofamily> <protoname> <device>
     #         <nametoaddrlibs>
     # The "-" in <nametoaddrlibs> for inet family transports indicates
     # redirection to the name service switch policies for "hosts" and
     # "services". The "-" may be replaced by nametoaddr libraries that
     # comply with the SVr4 specs, in which case the name service switch
     # will not be used for netdir_getbyname, netdir_getbyaddr,
     # gethostbyname, gethostbyaddr, getservbyname, and getservbyport.
     # There are no nametoaddr_libs for the inet family in Solaris anymore.
     udp6       tpi_clts      v     inet6   udp    /dev/udp6       -
     tcp6       tpi_cots_ord  v     inet6   tcp    /dev/tcp6       -
     udp        tpi_clts      v     inet    udp    /dev/udp        -
     tcp        tpi_cots_ord  v     inet    tcp    /dev/tcp        -
     rawip      tpi_raw       -     inet    -      /dev/rawip      -
     ticlts     tpi_clts      v    loopback -      /dev/ticlts     straddr.so
     ticotsord  tpi_cots_ord  v    loopback -      /dev/ticotsord  straddr.so
     ticots     tpi_cots      v    loopback -      /dev/ticots     straddr.so


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File Formats                                         netconfig(4)

     dlopen(3DL),      getnetconfig(3NSL),      getnetpath(3NSL),

     System Administration Guide: IP Services

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