Manual page for IFCONFIG(8C)
ifconfig - configure network interface parameters
SYNOPSIS
/usr/etc/ifconfig
interface
[
address_family
]
[
address
[
dest_address
] ]
[
netmask
mask
]
[
broadcast
address
]
[
up
]
[
down
]
[
trailers
]
[
-trailers
]
[
arp
]
[
-arp
]
[
private
]
[
-private
]
[
metric
n
]
[
auto-revarp
]
/usr/etc/ifconfig
interface
[
protocol_family
]
DESCRIPTION
ifconfig
is used to assign an address
to a network interface and/or to configure
network interface parameters.
ifconfig
must be used at boot time to define the network address
of each interface present on a machine; it may also be used at
a later time to redefine an interface's address
or other operating parameters.
Used without options,
ifconfig
displays the current configuration for a network interface.
If a protocol family is specified,
ifconfig
will report only the details specific to that protocol family.
Only the super-user may modify the configuration
of a network interface.
The
interface
parameter is a string of the form
nameunit,
for example
le0
or
ie1.
Three special interface names,
-a,
-ad
and
-au,
are reserved and refer to all or a subset
of the interfaces in the system.
If one of these interface names is given, the commands following it are applied
to all of the interfaces that match:
- -a
-
Apply the commands to all interfaces in the system.
- -ad
-
Apply the commands to all ``down'' interfaces in the system.
- -au
-
Apply the commands to all ``up'' interfaces in the system.
Since an interface may receive transmissions in differing protocols,
each of which may require separate naming schemes, the parameters and
addresses are interpreted according to
the rules of some address family,
specified by the
address_family
parameter. The address families currently supported are
ether and inet.
If no address family is specified,
inet
is assumed.
For the
TCP/IP
family
(inet),
the address is either a host name present in the host name data
base (see
hosts.5
or in the
Network Information Service
(NIS)
map
hosts,
or a
TCP/IP
address expressed in the Internet standard
``dot notation''.
Typically, an Internet address specified in dot notation
will consist of your system's network number and the machine's
unique host number.
A typical Internet address is
192.9.200.44,
where
192.9.200
is the network number and
44
is the machine's
host number.
For the
ether
address family,
the address is an Ethernet address represented as
x:x:x:x:x:x
where
x
is a hexadecimal number between 0 and ff.
Only the super-user may use the
ether
address family.
If the
dest_address
parameter is supplied in addition to the
address
parameter, it specifies the address of
the correspondent on the other end
of a point to point link.
OPTIONS
- up
-
Mark an interface ``up''.
This happens automatically when setting the
first address on an interface.
The
up
option
enables an interface after an
ifconfig down,
reinitializing the hardware.
- down
-
Mark an interface ``down''. When an interface is
marked ``down'', the system will not attempt to
transmit messages through that interface.
If possible, the interface will be reset to disable reception as well.
This action does not automatically disable routes using the interface.
- trailers
-
This flag used to cause a non-standard encapsulation of inet packets
on certain link levels.
Sun drivers no longer use this flag, but it is ignored for compatibility.
- -trailers
-
Disable the use of a ``trailer'' link level encapsulation.
- arp
-
Enable the use of the Address Resolution Protocol in mapping
between network level addresses and link level addresses (default).
This is currently implemented for mapping between
TCP/IP
addresses and 10Mb/s Ethernet addresses.
- -arp
-
Disable the use of the Address Resolution Protocol.
- private
-
Tells the
in.routed
routing daemon
(see
routed.8c
that the interface should not be advertised.
- -private
-
Specify unadvertised interfaces.
- auto-revarp
-
Use the Reverse Address Resolution Protocol (RARP) to automatically
acquire an address for this interface. Available beginning
with SunOS 4.1.1 Rev B.
- metric n
-
Set the routing metric of the interface to
n,
default 0.
The routing metric is used by the routing protocol
(routed(8C)).
Higher metrics have the effect of making a route
less favorable; metrics are counted as addition hops
to the destination network or host.
- netmask mask
-
(inet only)
Specify how much of the address to reserve for subdividing
networks into sub-networks.
The mask includes the network part of the local address
and the subnet part, which is taken from the host field of the address.
The mask can be specified as a single hexadecimal number
with a leading 0x, with a dot-notation address,
or with a pseudo-network name listed in the network table
networks.5
The mask contains 1's for the bit positions in the 32-bit address
which are to be used for the network and subnet parts,
and 0's for the host part.
The mask should contain at least the standard network portion,
and the subnet field should be contiguous with the network
portion.
If a
`+'
(plus sign) is given for the netmask value,
then the network number is looked up in the
NIS
netmasks.byaddr
map
(or in the
/etc/netmasks)
file if not running the
NIS
service.
- broadcast address
-
(inet
only)
Specify the address to use to represent broadcasts to the
network.
The default broadcast address is the
address with a host part of all 0's.
A
+
(plus sign) given for the broadcast value causes the broadcast address to
be reset to a default appropriate for the (possibly new) address
and netmask.
Note that the arguments of
ifconfig
are interpreted left to right,
and therefore
ifconfig -a netmask + broadcast +
and
ifconfig -a broadcast + netmask +
may result in different values being assigned for the interfaces'
broadcast addresses.
EXAMPLES
If your workstation is not attached to an Ethernet, the
ie0
interface should be marked ``down'' as follows:
ifconfig ie0 down
To print out the addressing information for each interface, use
ifconfig -a
To reset each interface's broadcast address after the netmasks
have been correctly set, use
ifconfig -a broadcast +
FILES
- /dev/nit
-
- /etc/netmasks
-
SEE ALSO
intro.3
ethers.3n
arp.4p
hosts.5
netmasks.5
networks.5
netstat.8c
rc.8
routed.8c
DIAGNOSTICS
Messages indicating the specified interface does not exist, the
requested address is unknown, or the user is not privileged and
tried to alter an interface's configuration.
NOTES
The network information service
(NIS)
was formerly known as Sun Yellow Pages
(YP).
The functionality of the two remains the same;
only the name has changed.
Created by unroff & hp-tools.
© somebody (See intro for details). All Rights Reserved.
Last modified 11/5/97