1.\" Copyright (c) Andrey V. Elsukov <ae@FreeBSD.org> 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd November 7, 2014 28.Dt ME 4 29.Os 30.Sh NAME 31.Nm me 32.Nd encapsulating network device 33.Sh SYNOPSIS 34To compile the 35driver into the kernel, place the following line in the kernel 36configuration file: 37.Bd -ragged -offset indent 38.Cd "device me" 39.Ed 40.Pp 41Alternatively, to load the 42driver as a module at boot time, place the following line in 43.Xr loader.conf 5 : 44.Bd -literal -offset indent 45if_me_load="YES" 46.Ed 47.Sh DESCRIPTION 48The 49.Nm 50network interface pseudo device encapsulates datagrams 51into IP. 52These encapsulated datagrams are routed to a destination host, 53where they are decapsulated and further routed to their final destination. 54.Pp 55.Nm 56interfaces are dynamically created and destroyed with the 57.Xr ifconfig 8 58.Cm create 59and 60.Cm destroy 61subcommands. 62.Pp 63This driver corresponds to RFC 2004. 64Datagrams are encapsulated into IP with a shorter encapsulation. 65The original 66IP header is modified and the modifications are inserted between the 67so modified header and the original payload. 68The protocol number 55 is used for outer header. 69.Sh NOTES 70For correct operation, the 71.Nm 72device needs a route to the decapsulating host that does not run over the tunnel, 73as this would be a loop. 74.Sh SEE ALSO 75.Xr gif 4 , 76.Xr gre 4 , 77.Xr inet 4 , 78.Xr ip 4 , 79.Xr netintro 4 , 80.Xr protocols 5 , 81.Xr ifconfig 8 , 82.Xr sysctl 8 83.Sh AUTHORS 84.An Andrey V. Elsukov Aq Mt ae@FreeBSD.org 85