lo(4)
NAME
lo − software loopback network interface
DESCRIPTION
The loop interface is a software loopback mechanism which may be used for performance analysis, software testing, and/or local communication. By convention, the loopback interface is usually assigned the address 127.0.0.1 (non-standard); this address is set in /etc/rc, and may be changed with the SIOCSIFADDR ioctl.
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.