LO(4)LO(4)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 ALSOintro(4N), inet(4F), ns(4F)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.
4.2 Berkeley Distribution May 21, 1986 LO(4)