.\" $NetBSD: lagg.4,v 1.4.2.1 2023/10/19 07:23:51 martin Exp $ .\" .\" Copyright (c) 2005, 2006 Reyk Floeter .\" .\" Permission to use, copy, modify, and distribute this software for any .\" purpose with or without fee is hereby granted, provided that the above .\" copyright notice and this permission notice appear in all copies. .\" .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF .\" MERCHANTABILITY AND FITNESS. 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Neither the name of the project nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .Dd April 2, 2020 .Dt LAGG 4 .Os .Sh NAME .Nm lagg .Nd link aggregation and link failover interface .Sh SYNOPSIS .Cd "pseudo-device lagg" .Sh DESCRIPTION The .Nm interface allows aggregation of multiple network interfaces as one virtual .Nm interface for the purpose of providing fault-tolerance and high-speed links. .Pp A .Nm interface can be created using the .Ic ifconfig lagg Ns Ar N Ic create command. It can use different link aggregation protocols specified using the .Ic laggproto Ar proto option. Child interfaces can be added using the .Ic laggport Ar child-iface option and removed using the .Ic -laggport Ar child-iface option. A priority of each child interface can be configured using the .Ic laggport Ar child-iface pri Ar N or .Ic laggportpri Ar child-iface Ar N option. The interface preferentially uses the child interface that is the smallest numeric in the priority. .Pp The driver currently supports the aggregation protocols .Ic failover , .Ic loadbalance , .Ic lacp , and .Ic none (the default). The protocols determine which ports are used for outgoing traffic and whether a specific port accepts incoming traffic. The interface link state is used to validate if the port is active or not. .Bl -tag -width loadbalance .It Ic failover Sends traffic only through the active port that is the highest priority. When the same priority is configured, The first interface added is used for sending traffic. If the link-state of the sending port becomes down, The next priority port is used. .Pp Received traffic is accepted through all active port if .Ic laggfailover Nm rx-all option is enabled. The option is enabled by default, and it can be disabled by .Ic laggfailover Nm -rx-all option. If the option is disabled, received traffic is only accepted through the sending port. .It Ic loadbalance Balances outgoing traffic across the active ports based on hashed protocol header information and accepts incoming traffic from any active port. This is a static setup and does not negotiate aggregation with the peer or exchange frames to monitor the link. The hash includes the Ethernet source and destination address, and, if available, the VLAN tag, and the IP source and destination address. .It Ic lacp Supports the IEEE 802.1AX (formerly 802.3ad) Link Aggregation Control Protocol (LACP) and the Marker Protocol. LACP will negotiate a set of aggregable links wit the peer in to a Link Aggregated Group. The LAG is composed of ports of the different speed, set to full-duplex operation, if .Ic lagglacp Nm multi-speed option is configured. The function can be disabled by .Ic lagglacp Nm \-multi-speed option. Outgoing traffic across the distributing ports based on hashed protocol header information and accepts incoming traffic from any collecting port. The maximum number of active ports in a LAG can be configured by .Ic lagglacp Nm maxports Ar N option. .It Ic none This protocol is intended to do nothing: it disables any traffic without disabling the .Nm interface itself. .El .Pp Each .Nm interface is created at runtime using interface cloning. This is most easily done with the .Xr ifconfig 8 .Cm create command. .Pp The MTU of the .Xr lagg 4 is applied to each physical interfaces. And the physical interfaces can not change its MTU directly. .Sh EXAMPLES Create a link aggregation using LACP with two .Xr wm 4 Gigabit Ethernet interfaces: .Bd -literal -offset indent # ifconfig wm0 up # ifconfig wm1 up # ifconfig lagg0 create # ifconfig lagg0 laggproto lacp laggport wm0 laggport wm1 \e 192.168.1.1 netmask 255.255.255.0 .Ed .Pp Create a link aggregation using FAILOVER with two .Xr wm 4 Gigabit Ethernet interfaces and set each priority: .Bd -literal -offset indent # ifconfig wm0 up # ifconfig wm1 up # ifconfig lagg0 create # ifconfig lagg0 laggproto failover # ifconfig lagg0 laggport wm0 pri 1000 # ifconfig lagg0 laggport wm1 pri 2000 # ifconfig lagg0 inet 192.168.1.1 netmask 255.255.255.0 .Ed .Sh SEE ALSO .Xr ifconfig 8 .Sh HISTORY The .Nm device first appeared in .Nx 10.0 . .Sh AUTHORS .An -nosplit The .Nm driver was written under the name .Nm trunk by .An Reyk Floeter Aq Mt reyk@openbsd.org . .Sh BUGS There is no way to configure LACP administrative variables, including system priority. The current implementation always performs active-mode LACP and uses 0x8000 as system priority.