Copyright (c) 1983 The Regents of the University of California.
All rights reserved.
Redistribution and use in source and binary forms are permitted
provided that the above copyright notice and this paragraph are
duplicated in all such forms and that any documentation,
advertising materials, and other materials related to such
distribution and use acknowledge that the software was developed
by the University of California, Berkeley. The name of the
University may not be used to endorse or promote products derived
from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
@(#)lo.4 6.4 (Berkeley) 02/14/89
All rights reserved.
Redistribution and use in source and binary forms are permitted
provided that the above copyright notice and this paragraph are
duplicated in all such forms and that any documentation,
advertising materials, and other materials related to such
distribution and use acknowledge that the software was developed
by the University of California, Berkeley. The name of the
University may not be used to endorse or promote products derived
from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
@(#)lo.4 6.4 (Berkeley) 02/14/89
LO 4 ""
C 5 NAME
lo - software loopback network interface
SYNOPSIS
pseudo-device loop DESCRIPTION
The
loop interface is a software loopback mechanism which may be
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.
DIAGNOSTICS
lo%d: can't handle af%d. The interface was handed
a message with addresses formatted in an unsuitable address
family; the packet was dropped.
SEE ALSO
intro(4), inet(4), ns(4)
BUGS
Previous versions of the 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.