1.\" Copyright (c) 2016 Luigi Rizzo, Universita` di Pisa 2.\" 3.\" Redistribution and use in source and binary forms, with or without 4.\" modification, are permitted provided that the following conditions 5.\" are met: 6.\" 1. Redistributions of source code must retain the above copyright 7.\" notice, this list of conditions and the following disclaimer. 8.\" 2. Redistributions in binary form must reproduce the above copyright 9.\" notice, this list of conditions and the following disclaimer in the 10.\" documentation and/or other materials provided with the distribution. 11.\" 12.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 13.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 14.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 15.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 16.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 17.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 18.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 19.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 20.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 21.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 22.\" SUCH DAMAGE. 23.\" 24.Dd November 21, 2020 25.Dt BRIDGE 8 26.Os 27.Sh NAME 28.Nm bridge 29.Nd netmap client to bridge two netmap ports 30.Sh SYNOPSIS 31.Bk -words 32.Bl -tag -width "bridge" 33.It Nm 34.Op Fl i Ar port 35.Op Fl b Ar batch size 36.Op Fl w Ar wait-link 37.Op Fl v 38.Op Fl c 39.El 40.Ek 41.Sh DESCRIPTION 42.Nm 43is a simple netmap application that bridges packets between two netmap ports. 44If the two netmap ports use the same netmap memory region 45.Nm 46forwards packets without copying the packets payload (zero-copy mode), unless 47explicitly prevented by the 48.Fl c 49flag. 50.Pp 51When bridging two physical ports, it is necessary that both NICS are in 52promiscuous mode, otherwise unicast traffic directed to other hosts will 53be dropped by the hardware, and bridging will not work. 54.Pp 55When bridging the hardware rings of a physical port with the corresponding 56host rings, it is necessary to turn off the offloads, because netmap does 57not prepare the NIC rings with offload information. 58Example: 59.Bd -literal -offset indent 60ifconfig em0 -rxcsum -txcsum -tso4 -tso6 -lro 61.Ed 62.Pp 63Available options: 64.Bl -tag -width Ds 65.It Fl i Ar port 66Name of the netmap port. 67It can be supplied up to two times to identify the ports that must be bridged. 68Any netmap port type (physical interface, VALE switch, pipe, monitor port...) 69can be used. 70If the option is supplied only once, then it must be for a physical interface and, in that case, 71.Nm 72will bridge the port and the host stack. 73.It Fl b Ar batch-size 74Maximum number of packets to send in one operation. 75.It Fl w Ar wait-link 76indicates the number of seconds to wait before transmitting. 77It defaults to 2, and may be useful when talking to physical 78ports to let link negotiation complete before starting transmission. 79.It Fl v 80Enable verbose mode 81.It Fl c 82Disable zero-copy mode. 83.El 84.Sh SEE ALSO 85.Xr netmap 4 , 86.Xr lb 8 , 87.Xr pkt-gen 8 88.Sh AUTHORS 89.An -nosplit 90.Nm 91has been written by 92.An Luigi Rizzo 93and 94.An Matteo Landi 95at the Universita` di Pisa, Italy. 96