netconfig(4)netconfig(4)NAMEnetconfig - network configuration database
SYNOPSISDESCRIPTION
The network configuration database, is a system file used to store
information about networks that are connected to the system. The data‐
base and the routines that access it (see getnetconfig(3N)) are part of
the Network Selection component. The Network Selection component also
includes routines to provide application-specific network search paths.
These routines access the database based on the environment variable
NETPATH (see environ(5)).
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 or Lines in that begin with a # (hash) in column 1 are
treated as comments.
Each of the valid lines in the database correspond to an available
transport. Each entry is of the form:
network_ID semantics_flag protocol_family protocol_name net‐
work_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_ID's on a system must
be unique.
semantics The semantics field is a string identifying the ``seman‐
tics'' of the network, that is, the set of services it sup‐
ports, by identifying the service interface it provides.
The semantics field is mandatory. The following semantics
are recognized.
Transport Provider Interface, connectionless
Transport Provider Interface, connection oriented, sup‐
ports
orderly release.
flag The flag field records certain two-valued (``true'' and
``false'') attributes of networks. flag is a string com‐
posed of a combination of characters, each of which indi‐
cates 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 attributes are present. Only
one character is currently recognized:
Visible (``default'') network.
Used when the environment variable NET‐
PATH 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 identifies
a protocol family. The protocol_family identifier follows
the same rules as those for network_IDs; the string con‐
sists 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 indicates that no protocol family
identifier applies (the network is experimental). An exam‐
ple protocol family:
Internetwork: UDP, TCP, etc.
protocol_name
The protocol_name field contains a string that identifies a
protocol. The protocol_name identifier follows the same
rules as those for network_IDs; that is, the string con‐
sists of non-NULL characters, it has a length of at least
1, and there is no maximum length specified. A ``-'' indi‐
cates that none of the names listed apply. The following
protocol names are recognized.
Transmission Control Protocol
User Datagram Protocol
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 network_device
must be specified.
translation_libraries
The name-to-address translation libraries support a
``directory service'' (a name-to-address mapping service)
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 nss‐
witch.conf(4)). For networks of other families, a ``-''
indicates non-functional name-to-address mapping. Other‐
wise, 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.
Itanium(R)-based libraries are located in the directories.
For backward compatibility appropriate links are provided
in for example, is linked to If the library field is modi‐
fied and both Itanium-based and PA-RISC libraries are pro‐
vided, links must be created in the directory to accommo‐
date backward compatibility to PA-RISC library naming con‐
ventions. If an absolute library pathname is specified for
a particular service, the applications using the service
work only for that architecture.
Each field corresponds to an element in the structure. and the identi‐
fiers described on this manual page are defined in This structure
includes the following members:
Network ID, including NULL terminator.
Semantics.
Flags.
Protocol family.
Protocol name.
Full pathname of the network device.
Number of directory lookup libraries.
Names of the name-to-address translation libraries.
Reserved for future expansion.
The nc_semantics field takes the following values, corresponding to the
semantics identified above:
The nc_flag field is a bitfield. The following bit, corresponding to
the attribute identified above, is currently recognized. indicates the
absence of any attributes.
EXAMPLES
Below is a sample file:
AUTHOR
was developed by Sun Microsystems, Inc.
FILESSEE ALSOgetnetconfig(3N), getnetpath(3N), nsswitch.conf(4).
netconfig(4)