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.
The name of the interface. This is usually a driver name followed by a unit number, for example eth0 for the first Ethernet interface.
This flag causes the interface to be activated. It is implicitly specified if an address is assigned to the interface.
This flag causes the driver for this interface to be shut down.
Enable or disable the use of the ARP protocol on this interface.
Enable or disable the promiscuous mode of the interface. If selected, all packets on the network will be received by the interface.
Enable or disable all-multicast mode. If selected, all multicast packets on the network will be received by the interface.
This parameter sets the interface metric.
This parameter sets the Maximum Transfer Unit (MTU) of an interface.
Set the remote IP address for a point-to-point link (such as PPP). This keyword is now obsolete; use the pointopoint keyword instead.
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 an IPv6 address to an interface.
Remove an IPv6 address from an interface.
Create a new SIT (IPv6-in-IPv4) device, tunnelling to the given destination.
Set the interrupt line used by this device. Not all devices can dynamically change their IRQ setting.
Set the start address in I/O space for this device.
Set the start address for shared memory used by this device. Only a few devices need this.
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.
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.
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).
Set the multicast flag on the interface. This should not normally be needed as the drivers set the flag correctly themselves.
The IP address to be assigned to this interface.
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 :)