Provided by: freebsd-manpages_8.2-1_all bug

NAME

     lagg — link aggregation and link failover interface

SYNOPSIS

     To compile this driver into the kernel, place the following line in your kernel
     configuration file:

           device lagg

     Alternatively, to load the driver as a module at boot time, place the following line in
     loader.conf(5):

           if_lagg_load="YES"

DESCRIPTION

     The lagg interface allows aggregation of multiple network interfaces as one virtual lagg
     interface for the purpose of providing fault-tolerance and high-speed links.

     A lagg interface can be created using the ifconfig laggN create command.  It can use
     different link aggregation protocols specified using the laggproto proto option.  Child
     interfaces can be added using the laggport child-iface option and removed using the
     -laggport child-iface option.

     The driver currently supports the aggregation protocols failover (the default), fec, lacp,
     loadbalance, roundrobin, and none.  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.

     failover     Sends traffic only through the active port.  If the master port becomes
                  unavailable, the next active port is used.  The first interface added is the
                  master port; any interfaces added after that are used as failover devices.

                  By default, received traffic is only accepted when they are received through
                  the active port.  This constraint can be relaxed by setting the
                  net.link.lagg.failover_rx_all sysctl(8) variable to a nonzero value, which is
                  useful for certain bridged network setups.

     fec          Supports Cisco EtherChannel.  This is a static setup and does not negotiate
                  aggregation with the peer or exchange frames to monitor the link.

     lacp         Supports the IEEE 802.3ad Link Aggregation Control Protocol (LACP) and the
                  Marker Protocol.  LACP will negotiate a set of aggregable links with the peer
                  in to one or more Link Aggregated Groups.  Each LAG is composed of ports of the
                  same speed, set to full-duplex operation.  The traffic will be balanced across
                  the ports in the LAG with the greatest total speed, in most cases there will
                  only be one LAG which contains all ports.  In the event of changes in physical
                  connectivity, Link Aggregation will quickly converge to a new configuration.

     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.

     roundrobin   Distributes outgoing traffic using a round-robin scheduler through all active
                  ports and accepts incoming traffic from any active port.

     none         This protocol is intended to do nothing: it disables any traffic without
                  disabling the lagg interface itself.

     Each lagg interface is created at runtime using interface cloning.  This is most easily done
     with the ifconfig(8) create command or using the cloned_interfaces variable in rc.conf(5).

     The MTU of the first interface to be added is used as the lagg MTU.  All additional
     interfaces are required to have exactly the same value.

EXAMPLES

     Create a 802.3ad link aggregation using LACP with two bge(4) Gigabit Ethernet interfaces:

           # ifconfig bge0 up
           # ifconfig bge1 up
           # ifconfig lagg0 laggproto lacp laggport bge0 laggport bge1 \
                   192.168.1.1 netmask 255.255.255.0

     The following example uses an active failover interface to set up roaming between wired and
     wireless networks using two network devices.  Whenever the wired master interface is
     unplugged, the wireless failover device will be used:

           # ifconfig em0 up
           # ifconfig ath0 ether 00:11:22:33:44:55
           # ifconfig create wlan0 wlandev ath0 ssid my_net up
           # ifconfig lagg0 laggproto failover laggport em0 laggport wlan0 \
                   192.168.1.1 netmask 255.255.255.0

     (Note the mac address of the wireless device is forced to match the wired device as a
     workaround.)

SEE ALSO

     ng_fec(4), ng_one2many(4), sysctl(8), ifconfig(8)

HISTORY

     The lagg device first appeared in FreeBSD 6.3.

AUTHORS

     The lagg driver was written under the name trunk by Reyk Floeter <reyk@openbsd.org>.  The
     LACP implementation was written by YAMAMOTO Takashi for NetBSD.

BUGS

     There is no way to configure LACP administrative variables, including system and port
     priorities.  The current implementation always performs active-mode LACP and uses 0x8000 as
     system and port priorities.