NAME    [Toc]    [Back]

       lo - Software loopback network interface

SYNOPSIS    [Toc]    [Back]

       pseudo-device loop

DESCRIPTION    [Toc]    [Back]

       The  loopback  interface  is a software loopback mechanism
       which is used for performance analysis, software  testing,
       and/or  local  communication. As with other network interfaces,
 the loopback interface must have network  addresses
       assigned  for  each  address family with which it is to be
       used. These addresses may be set or changed with the SIOCSIFADDR
  ioctl.  The loopback interface should be the last
       interface configured, as protocols may use  the  order  of
       configuration  as  an indication of priority. The loopback
       should never be configured first unless no hardware interfaces
 exist.

NOTES    [Toc]    [Back]

       Previous  versions of the UNIX system enabled the loopback
       interface  automatically,  using  a  nonstandard  Internet
       address (127.1). Use of that address is now discouraged; a
       reserved host address for the local network should be used
       instead.

ERRORS    [Toc]    [Back]

       The  interface was handed a message with addresses formatted
 in  an  unsuitable  address  family;  the  packet  was
       dropped.

SEE ALSO    [Toc]    [Back]

       Networking: inet(7), netintro(7)



                                                            lo(7)