1.\" $OpenBSD: trunk.4,v 1.18 2006/06/09 13:53:34 jmc Exp $ 2.\" 3.\" Copyright (c) 2005, 2006 Reyk Floeter <reyk@openbsd.org> 4.\" 5.\" Permission to use, copy, modify, and distribute this software for any 6.\" purpose with or without fee is hereby granted, provided that the above 7.\" copyright notice and this permission notice appear in all copies. 8.\" 9.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16.\" 17.\" $FreeBSD$ 18.\" 19.Dd April 17, 2007 20.Dt LAGG 4 21.Os 22.Sh NAME 23.Nm lagg 24.Nd link aggregation and link failover interface 25.Sh SYNOPSIS 26To compile this driver into the kernel, 27place the following line in your 28kernel configuration file: 29.Bd -ragged -offset indent 30.Cd "device lagg" 31.Ed 32.Pp 33Alternatively, to load the driver as a 34module at boot time, place the following line in 35.Xr loader.conf 5 : 36.Bd -literal -offset indent 37if_lagg_load="YES" 38.Ed 39.Sh DESCRIPTION 40The 41.Nm 42interface allows aggregation of multiple network interfaces as one virtual 43.Nm 44interface for the purpose of providing fault-tolerance and high-speed links. 45.Pp 46A 47.Nm 48interface can be created using the 49.Ic ifconfig lagg Ns Ar N Ic create 50command. 51It can use different link aggregation protocols specified 52using the 53.Ic laggproto Ar proto 54option. 55Child interfaces can be added using the 56.Ic laggport Ar child-iface 57option and removed using the 58.Ic -laggport Ar child-iface 59option. 60.Pp 61The driver currently supports the aggregation protocols 62.Ic failover 63(the default), 64.Ic fec , 65.Ic lacp , 66.Ic loadbalance , 67.Ic roundrobin , 68and 69.Ic none . 70The protocols determine which ports are used for outgoing traffic 71and whether a specific port accepts incoming traffic. 72The interface link state is used to validate if the port is active or 73not. 74.Bl -tag -width loadbalance 75.It Ic failover 76Sends and receives traffic only through the master port. 77If the master port becomes unavailable, 78the next active port is used. 79The first interface added is the master port; 80any interfaces added after that are used as failover devices. 81.It Ic fec 82Supports Cisco EtherChannel. 83This is a static setup and does not negotiate aggregation with the peer or 84exchange frames to monitor the link. 85.It Ic lacp 86Supports the IEEE 802.3ad Link Aggregation Control Protocol (LACP) and the 87Marker Protocol. 88LACP will negotiate a set of aggregable links with the peer in to one or more 89Link Aggregated Groups. 90Each LAG is composed of ports of the same speed, set to full-duplex operation. 91The traffic will be balanced across the ports in the LAG with the greatest 92total speed, in most cases there will only be one LAG which contains all ports. 93In the event of changes in physical connectivity, Link Aggregation will quickly 94converge to a new configuration. 95.It Ic loadbalance 96Balances outgoing traffic across the active ports based on hashed 97protocol header information and accepts incoming traffic from 98any active port. 99This is a static setup and does not negotiate aggregation with the peer or 100exchange frames to monitor the link. 101The hash includes the Ethernet source and destination address, and, if 102available, the VLAN tag, and the IP source and destination address. 103.It Ic roundrobin 104Distributes outgoing traffic using a round-robin scheduler 105through all active ports and accepts incoming traffic from 106any active port. 107.It Ic none 108This protocol is intended to do nothing: it disables any traffic without 109disabling the 110.Nm 111interface itself. 112.El 113.Pp 114Each 115.Nm 116interface is created at runtime using interface cloning. 117This is 118most easily done with the 119.Xr ifconfig 8 120.Cm create 121command or using the 122.Va cloned_interfaces 123variable in 124.Xr rc.conf 5 . 125.Pp 126The MTU of the first interface to be added is used as the lagg MTU. 127All additional interfaces are required to have exactly the same value. 128.Sh EXAMPLES 129Create a 802.3ad link aggregation using LACP with two 130.Xr bge 4 131Gigabit Ethernet interfaces: 132.Bd -literal -offset indent 133# ifconfig bge0 up 134# ifconfig bge1 up 135# ifconfig lagg0 laggproto lacp laggport bge0 laggport bge1 \e 136 192.168.1.1 netmask 255.255.255.0 137.Ed 138.Pp 139The following example uses an active failover interface to set up roaming 140between wired and wireless networks using two network devices. 141Whenever the wired master interface is unplugged, the wireless failover 142device will be used: 143.Bd -literal -offset indent 144# ifconfig em0 up 145# ifconfig ath0 nwid my_net up 146# ifconfig lagg0 laggproto failover laggport em0 laggport ath0 \e 147 192.168.1.1 netmask 255.255.255.0 148.Ed 149.Sh SEE ALSO 150.Xr ng_fec 4 , 151.Xr ng_one2many 4 , 152.Xr ifconfig 8 153.Sh HISTORY 154The 155.Nm 156device first appeared in 157.Fx 6.3 . 158.Sh AUTHORS 159.An -nosplit 160The 161.Nm 162driver was written under the name 163.Nm trunk 164by 165.An Reyk Floeter Aq reyk@openbsd.org . 166The LACP implementation was written by 167.An YAMAMOTO Takashi 168for 169.Nx . 170.Sh BUGS 171There is no way to configure LACP administrative variables, including system 172and port priorities. 173The current implementation always performs active-mode LACP and uses 0x8000 as 174system and port priorities. 175.Pp 176WPA security does not currently work correctly with a wireless interface added 177to the lagg port. 178