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.Dd November 7, 2014 26.Dt ME 4 27.Os 28.Sh NAME 29.Nm me 30.Nd encapsulating network device 31.Sh SYNOPSIS 32To compile the 33driver into the kernel, place the following line in the kernel 34configuration file: 35.Bd -ragged -offset indent 36.Cd "device me" 37.Ed 38.Pp 39Alternatively, to load the 40driver as a module at boot time, place the following line in 41.Xr loader.conf 5 : 42.Bd -literal -offset indent 43if_me_load="YES" 44.Ed 45.Sh DESCRIPTION 46The 47.Nm 48network interface pseudo device encapsulates datagrams 49into IP. 50These encapsulated datagrams are routed to a destination host, 51where they are decapsulated and further routed to their final destination. 52.Pp 53.Nm 54interfaces are dynamically created and destroyed with the 55.Xr ifconfig 8 56.Cm create 57and 58.Cm destroy 59subcommands. 60.Pp 61This driver corresponds to RFC 2004. 62Datagrams are encapsulated into IP with a shorter encapsulation. 63The original 64IP header is modified and the modifications are inserted between the 65so modified header and the original payload. 66The protocol number 55 is used for outer header. 67.Sh NOTES 68For correct operation, the 69.Nm 70device needs a route to the decapsulating host that does not run over the tunnel, 71as this would be a loop. 72.Sh SEE ALSO 73.Xr gif 4 , 74.Xr gre 4 , 75.Xr inet 4 , 76.Xr ip 4 , 77.Xr netintro 4 , 78.Xr protocols 5 , 79.Xr ifconfig 8 , 80.Xr sysctl 8 81.Sh AUTHORS 82.An Andrey V. Elsukov Aq Mt ae@FreeBSD.org 83