Switch to SpeakEasy.net DSL

The Modular Manual Browser

Home Page
Manual: (SunOS-4.1.3)
Apropos / Subsearch:
optional field

IFCONFIG(8C)                                                      IFCONFIG(8C)

       ifconfig - configure network interface parameters

       /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 ]

       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  pro-
       tocol  family  is specified, ifconfig will report only the details spe-
       cific to that protocol family.  Only the super-user may modify the con-
       figuration 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

       -au            Apply the commands to all ``up'' interfaces in the  sys-

       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 fam-
       ily, specified by the address_family parameter.  The  address  families
       currently supported are ether and inet.  If no address family is speci-
       fied, 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, 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 repre-
       sented 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.

       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  compatibil-

       -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

       -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 hexadec-
                      imal  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  stan-
                      dard  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 ser-

       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 +


                      ifconfig -a broadcast + netmask +

                      may  result  in  different values being assigned for the
                      interfaces' broadcast addresses.

       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 +


       intro(3), ethers(3N), arp(4P), hosts(5), netmasks(5), networks(5)  net-
       stat(8C), rc(8), routed(8C)

       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.

       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.

                               14 December 1990                   IFCONFIG(8C)