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 a network address assigned to it.  The address 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(4N), inet(4F)

BUGS

An approved network address should be reserved for this interface. 

CX/UX Networking