FreeBSD 7.0 manual page repository

FreeBSD is a free computer operating system based on BSD UNIX originally. Many IT companies, like DeployIS is using it to provide an up-to-date, stable operating system.

lagg - link aggregation and link failover interface



      lagg - link aggregation and link failover interface


      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):


      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 spe‐
      cific port accepts incoming traffic.  The interface link state is used to
      validate if the port is active or not.
      failover     Sends and receives traffic only through the master 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.
      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.


      Create a 802.3ad link aggregation using LACP with two bge(4) Gigabit Eth‐
      ernet interfaces:
            # ifconfig bge0 up
            # ifconfig bge1 up
            # ifconfig lagg0 laggproto lacp laggport bge0 laggport bge1 \
      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 nwid my_net up
            # ifconfig lagg0 laggproto failover laggport em0 laggport ath0 \
      ng_fec(4), ng_one2many(4), ifconfig(8)


      The lagg device first appeared in FreeBSD 6.3.


      The lagg driver was written under the name trunk by Reyk Floeter
      〈〉.  The LACP implementation was written by YAMAMOTO
      Takashi for NetBSD.


      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.
      WPA security does not currently work correctly with a wireless interface
      added to the lagg port.


Based on BSD UNIX
FreeBSD is an advanced operating system for x86 compatible (including Pentium and Athlon), amd64 compatible (including Opteron, Athlon64, and EM64T), UltraSPARC, IA-64, PC-98 and ARM architectures. It is derived from BSD, the version of UNIX developed at the University of California, Berkeley. It is developed and maintained by a large team of individuals. Additional platforms are in various stages of development.