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 ``\blank''
or ``\tab''. 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.
semantics
The semantics field is a string identifying the ``semantics'' of the network, that is, the set of services it supports, by identifying the service interface it provides. The semantics field is mandatory. The following semantics
are recognized.
tpi_clts
Transport Provider Interface, connectionless
tpi_cots
Transport Provider Interface, connection oriented
tpi_cots_ord
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 attributes are present. Only one character is currently recognized:
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 identifies a protocol family. The protocol
family identifier 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 indicates that no protocol family identifier applies (the network is experimental). The following are examples:
loopback
Loopback (local to host).
inet
Internetwork: UDP, TCP, and the like.
inet6
Internetwork over IPv6: UDP, TCP, and the like.
implink
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
datakit
DATAKIT protocols
ccitt
CCITT protocols, X.25, and the like.
sna
IBM SNA
decnet
DECNET
dli
Direct data link interface
lat
LAT
hylink
NSC Hyperchannel
appletalk
Apple Talk
nit
Network Interface Tap
ieee802
IEEE 802.2; also ISO 8802
osi
Umbrella for all families used by OSI (for example, protosw lookup)
x25
CCITT X.25 in particular
osinet
AFI = 47, IDI = 4
gosip
U.S. Government OSI
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 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 recognized.
tcp
Transmission Control Protocol
udp
User Datagram Protocol
icmp
Internet Control Message 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 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(3C).
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 structure includes the following members:
char *nc_netid
Network ID, including NULL terminator.
unsigned longnc_semantics
Semantics.
unsigned longnc_flag
Flags.
char *nc_protofmly
Protocol family.
char *nc_proto
Protocol name.
char *nc_device
Full pathname of the network device.
unsigned longnc_nlookups
Number of directory lookup libraries.
char **nc_lookups
Names of the name-to-address translation libraries.
unsigned longnc_unused[9]
Reserved for future expansion.
The nc_semantics field takes the following values, corresponding to the semantics identified above:
NC_TPI_CLTS NC_TPI_COTS 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.
NC_VISIBLE
EXAMPLES
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
