NAME

ifconfig − configure network interface parameters

SYOPNSIS

/etc/ifconfig interface [ Ethernet_address ] [ hostname ] [ parameters ]

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.  Used without options, ifconfig displays the current configuration for a network interface.  Only the super-user may modify the configuration of a network interface. 

The interface parameter is a string of the form "name unit", for example "ie0". 

OPTIONS

Ethernet_address is the hardware Ethernet address of a given machine.  The address is a 6-byte hexadecimal value; each byte of the address is separated by a colon.  A typical Ethernet adddress is ‘8:0:20:1:1:A3’.  This address is contained in the ID PROM on the Sun-2 CPU Board, and is reported at boot time as one of the PROM monitor’s sign-on messages.  The Ethernet_address option is normally not used — the hardware supplies the default; the option is used only when trying to talk to a device which does not support ARP. 

hostname may be either the hostname of a given machine (present in the hostname database, hosts(5)), or the complete Internet address consisting of your system’s network number and the machine’s unique host number.  A typical Internet address might be "192.9.200.44", where "192.9.200" is the network number and "44" is the machine’s hostnumber. To find a machine’s Internet address, consult the local /etc/hosts file. 

The following parameters may be set with ifconfig:

   up Mark an interface "up". 

   down Mark an interface "down".  When an interface is marked "down", the system will not attempt to transmit messages through that interface. 

   trailers Enable the use of a "trailer" link level encapsulation when sending (default).  If a network interface supports trailers, the system will, when possible, encapsulate outgoing messages in a manner which minimizes the number of memory to memory copy operations performed by the receiver.

   −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 DARPA Internet addreses and 10Mb/s Ethernet addresses. 

   −arp Disable the use of the Address Resolution Protocol. 

EXAMPLE

If your workstation is not attached to an Ethernet, the ie0 interface should be marked "down" as follows:

ifconfig ie0 down

DIAGNOSTICS

Messages indicating the specified interface does not exit, the requested address is unknown, the user is not privileged and tried to alter an interface’s configuration. 

SEE ALSO

rc(8), intro(3N), netstat(8C)

Sun Release 3.2  —  Last change: 9 March 1986