1.\" 2.\" Copyright (c) 2013 Intel Corporation 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions, and the following disclaimer, 10.\" without modification. 11.\" 2. Redistributions in binary form must reproduce at minimum a disclaimer 12.\" substantially similar to the "NO WARRANTY" disclaimer below 13.\" ("Disclaimer") and any redistribution must be conditioned upon 14.\" including a substantially similar Disclaimer requirement for further 15.\" binary redistribution. 16.\" 17.\" NO WARRANTY 18.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19.\" "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20.\" LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR 21.\" A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22.\" HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 26.\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 27.\" IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28.\" POSSIBILITY OF SUCH DAMAGES. 29.\" 30.\" ntb driver man page. 31.\" 32.\" Author: Carl Delsey <carl@FreeBSD.org> 33.\" 34.\" $FreeBSD$ 35.\" 36.Dd Apr 11, 2013 37.Dt NTB 4 38.Os 39.Sh NAME 40.Nm ntb , 41.Nm ntb_hw , 42.Nm if_ntb 43.Nd Intel(R) Non-Transparent Bridge driver 44.Sh SYNOPSIS 45To compile this driver into your kernel, 46place the following lines in your kernel configuration file: 47.Bd -ragged -offset indent 48.Cd "device ntb_hw" 49.Cd "device if_ntb" 50.Ed 51.Pp 52Or, to load the driver as a module at boot, place the following line in 53.Xr loader.conf 5 : 54.Bd -literal -offset indent 55if_ntb_load="YES" 56.Ed 57.Sh DESCRIPTION 58The 59.Nm 60driver provides support for the Non-Transparent Bridge (NTB) in the Intel S1200, 61Xeon E3 and Xeon E5 processor families. 62.Pp 63The NTB allows you to connect two computer systems using a PCI-e link if they 64have the correct equipment and connectors. 65.Sh CONFIGURATION 66The NTB memory windows need to be configured by the BIOS. 67If your BIOS allows you to set their size, you should set the size of both 68memory windows to 1 MiB. 69This needs to be done on both systems. 70.Pp 71Each system needs to have a different IP address assigned. 72The MAC address is randomly generated. 73Also for maximum performance, the MTU should be set to 16 kiB. 74This can be down by adding the line below to 75.Xr rc.conf 5 : 76.Bd -literal -offset indent 77ifconfig_ntb0="inet 192.168.1.10 netmask 255.255.255.0 mtu 16384" 78.Ed 79.Pp 80And on the second system : 81.Bd -literal -offset indent 82ifconfig_ntb0="inet 192.168.1.11 netmask 255.255.255.0 mtu 16384" 83.Ed 84.Pp 85If you are using the UDP protocol, you may want to increase the 86.Va net.inet.udp.maxdgram 87.Xr sysctl 8 88variable. 89.Sh SEE ALSO 90.Xr rc.conf 5 , 91.Xr sysctl 8 92.Sh AUTHORS 93.An -nosplit 94The 95.Nm 96driver was developed by Intel and originally written by 97.An Carl Delsey Aq carl@FreeBSD.org. 98.Sh BUGS 99If the driver is unloaded, it cannot be reloaded without a system reboot. 100.Pp 101The network support is limited. 102It isn't fully configurable yet. 103It also isn't integrated into 104.Xr netgraph 4 105or 106.Xr bpf 4 . 107.Pp 108NTB to Root Port mode is not yet supported. 109.Pp 110There is no way to protect your system from malicious behavior on the other 111system once the link is brought up. 112Anyone with root or kernel access on the other system can read or write to 113any location on your system. 114In other words, only connect two systems that completely trust each other. 115