View Source: ifconfig(8) - Waikato Linux Users Group

Edit PageHistory Diff Info LikePages
IFCONFIG
!!!IFCONFIG
NAME
SYNOPSIS
DESCRIPTION
Address Families
OPTIONS
NOTES
FILES
BUGS
SEE ALSO
AUTHORS
----
!!NAME


ifconfig - configure a network interface
!!SYNOPSIS


__ifconfig [[interface]
ifconfig interface [[aftype] options | address
...__
!!DESCRIPTION


__Ifconfig__ is used to configure the kernel-resident
network interfaces. It is used at boot time to set up
interfaces as necessary. After that, it is usually only
needed when debugging or when system tuning is
needed.


If no arguments are given, __ifconfig__ displays the
status of the currently active interfaces. If a single
__interface__ argument is given, it displays the status
of the given interface only; if a single __-a__ argument
is given, it displays the status of all interfaces, even
those that are down. Otherwise, it configures an
interface.
!!Address Families


If the first argument after the interface name is recognized
as the name of a supported address family, that address
family is used for decoding and displaying all protocol
addresses. Currently supported address families include
__inet__ (TCP/IP, default), __inet6__ (IPv6),
__ax25__ (AMPR Packet Radio), __ddp__ (Appletalk Phase
2), __ipx__ (Novell IPX) and __netrom__ (AMPR Packet
radio).
!!OPTIONS


__interface__


The name of the interface. This is usually a driver name
followed by a unit number, for example __eth0__ for the
first Ethernet interface.


__up__


This flag causes the interface to be activated. It is
implicitly specified if an address is assigned to the
interface.


__down__


This flag causes the driver for this interface to be shut
down.


__[[-]arp__


Enable or disable the use of the ARP protocol on this
interface.


__[[-]promisc__


Enable or disable the __promiscuous__ mode of the
interface. If selected, all packets on the network will be
received by the interface.


__[[-]allmulti__


Enable or disable __all-multicast__ mode. If selected,
all multicast packets on the network will be received by the
interface.


__metric N__


This parameter sets the interface metric.


__mtu N__


This parameter sets the Maximum Transfer Unit (MTU) of an
interface.


__dstaddr addr__


Set the remote IP address for a point-to-point link (such as
PPP). This keyword is now obsolete; use the
__pointopoint__ keyword instead.


__netmask addr__


Set the IP network mask for this interface. This value
defaults to the usual class A, B or C network mask (as
derived from the interface IP address), but it can be set to
any value.


__add addr/prefixlen__


Add an IPv6 address to an interface.


__del addr/prefixlen__


Remove an IPv6 address from an interface.


__tunnel aa.bb.cc.dd__


Create a new SIT (IPv6-in-IPv4) device, tunnelling to the
given destination.


__irq addr__


Set the interrupt line used by this device. Not all devices
can dynamically change their IRQ setting.


__io_addr addr__


Set the start address in I/O space for this
device.


__mem_start addr__


Set the start address for shared memory used by this device.
Only a few devices need this.


__media type__


Set the physical port or medium type to be used by the
device. Not all devices can change this setting, and those
that can vary in what values they support. Typical values
for __type__ are __10base2__ (thin Ethernet),
__10baseT__ (twisted-pair 10Mbps Ethernet), __AUI__
(external transceiver) and so on. The special medium type of
__auto__ can be used to tell the driver to auto-sense the
media. Again, not all drivers can do this.


__[[-]broadcast [[addr]__


If the address argument is given, set the protocol broadcast
address for this interface. Otherwise, set (or clear) the
__IFF_BROADCAST__ flag for the interface.


__[[-]pointopoint [[addr]__


This keyword enables the __point-to-point__ mode of an
interface, meaning that it is a direct link between two
machines with nobody else listening on it.
If the address argument is also given, set the protocol
address of the other side of the link, just like the
obsolete __dstaddr__ keyword does. Otherwise, set or
clear the __IFF_POINTOPOINT__ flag for the
interface.


__hw class address__


Set the hardware address of this interface, if the device
driver supports this operation. The keyword must be followed
by the name of the hardware class and the printable ASCII
equivalent of the hardware address. Hardware classes
currently supported include __ether__ (Ethernet),
__ax25__ (AMPR AX.25), __ARCnet__ and __netrom__
(AMPR NET/ROM).


__multicast__


Set the multicast flag on the interface. This should not
normally be needed as the drivers set the flag correctly
themselves.


__address__


The IP address to be assigned to this
interface.


__txqueuelen length__


Set the length of the transmit queue of the device. It is
useful to set this to small values for slower devices with a
high latency (modem links, ISDN) to prevent fast bulk
transfers from disturbing interactive traffic like telnet
too much.
!!NOTES


Since kernel release 2.2 there are no explicit interface
statistics for alias interfaces anymore. The statistics
printed for the original address are shared with all alias
addresses on the same device. If you want per-address
statistics you should add explicit accounting rules for the
address using the __ipchains(8)__ command.


Since net-tools 1.60-4 ifconfig is printing byte counters
with SI units. So 1 KiB are 2^10 byte. Note, the numbers are
truncated to one decimal (which can by quite a large error
if you consider 0.1 PiB is 112.589.990.684.262 bytes
:)


Interrupt problems with Ethernet device drivers fail with
EAGAIN ''(SIOCSIIFLAGS: Resource temporarily
unavailable)'' it is most likely a interrupt conflict. See
''http://www.scyld.com/expert/irq-conflict.html'' for
more information.
!!FILES


''/proc/net/socket
/proc/net/dev
/proc/net/if_inet6''
!!BUGS


While appletalk DDP and IPX addresses will be displayed they
cannot be altered by this command.
!!SEE ALSO


route(8), netstat(8), arp(8), rarp(8), ipchains(8)
http://physics.nist.gov/cuu/Units/binary.html - Prefixes for
binary multiples
!!AUTHORS


Fred N. van Kempen,
Alan Cox,
Phil Blundell,
Andi Kleen;
Bernd Eckenfels,
----
21 pages link to ifconfig(8):
This page is a man page (or other imported legacy content). We are unable to automatically determine the license status of this page.
Last edited on Monday, June 3, 2002 6:56:39 pm by "perry"
Edit PageHistory Diff Info LikePages