NAME

ifconfig − configure network interface parameters

SYOPNSIS

/etc/ifconfig interface [ address ] [ 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.  The interface parameter is a string of the form “name unit”, for example “en0”, while the address is either a host name present in the host name data base, hosts(5), or a DARPA Internet address expressed in the Internet standard “dot notation”.

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. 

Ifconfig displays the current configuration for a network interface when no optional parameters are supplied. 

Only the super-user may modify the configuration of a network interface. 

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(4N), netstat(1)

Sun System Release 1.0  —  28 August 1983