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.
A loop interface can be created at runtime
using the ifconfig loN
create command or by setting up a
hostname.if(5) configuration file for
netstart(8). The lo0 interface will always
exist and cannot be destroyed using
ifconfig(8).
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(2).
DIAGNOSTICS
- lo0: can't handle afX.
- The interface was handed a message with addresses formatted in an unsuitable address family; the packet was dropped.
SEE ALSO
inet(4), inet6(4), netintro(4), hostname.if(5), ifconfig(8), netstart(8)
HISTORY
The lo device appeared in
4.2BSD.