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32 .\" @(#)lo.4 8.1 (Berkeley) 6/5/93
33 .\" $FreeBSD: src/share/man/man4/lo.4,v 1.7.2.1 2001/08/17 13:08:38 ru Exp $
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41 .Nd software loopback network interface
43 .Cd "pseudo-device loop"
47 interface is a software loopback mechanism which may be
48 used for performance analysis, software testing, and/or local
50 As with other network interfaces, the loopback interface must have
51 network addresses assigned for each address family with which it is to be used.
53 may be set or changed with the
56 The loopback interface should be the last interface configured,
57 as protocols may use the order of configuration as an indication of priority.
60 be configured first unless no hardware
64 .It lo%d: can't handle af%d.
65 The interface was handed
66 a message with addresses formatted in an unsuitable address
67 family; the packet was dropped.
79 Previous versions of the system enabled the loopback interface
80 automatically, using a nonstandard Internet address (127.1).
81 Use of that address is now discouraged; a reserved host address
82 for the local network should be used instead.