Friday, September 5, 2014

Macam-macam bonding mode

mode

 Specifies one of the bonding policies. The default is
 balance-rr (round robin).  Possible values are:

 balance-rr or 0

  Round-robin policy: Transmit packets in sequential
  order from the first available slave through the
  last.  This mode provides load balancing and fault
  tolerance.

 active-backup or 1

  Active-backup policy: Only one slave in the bond is
  active.  A different slave becomes active if, and only
  if, the active slave fails.  The bond's MAC address is
  externally visible on only one port (network adapter)
  to avoid confusing the switch.

  In bonding version 2.6.2 or later, when a failover
  occurs in active-backup mode, bonding will issue one
  or more gratuitous ARPs on the newly active slave.
  One gratuitous ARP is issued for the bonding master
  interface and each VLAN interfaces configured above
  it, provided that the interface has at least one IP
  address configured.  Gratuitous ARPs issued for VLAN
  interfaces are tagged with the appropriate VLAN id.

  This mode provides fault tolerance.  The primary
  option, documented below, affects the behavior of this
  mode.

 balance-xor or 2

  XOR policy: Transmit based on the selected transmit
  hash policy.  The default policy is a simple [(source
  MAC address XOR'd with destination MAC address XOR
  packet type ID) modulo slave count].  Alternate transmit
  policies may be selected via the xmit_hash_policy option,
  described below.

  This mode provides load balancing and fault tolerance.

 broadcast or 3

  Broadcast policy: transmits everything on all slave
  interfaces.  This mode provides fault tolerance.

 802.3ad or 4

  IEEE 802.3ad Dynamic link aggregation.  Creates
  aggregation groups that share the same speed and
  duplex settings.  Utilizes all slaves in the active
  aggregator according to the 802.3ad specification.

  Slave selection for outgoing traffic is done according
  to the transmit hash policy, which may be changed from
  the default simple XOR policy via the xmit_hash_policy
  option, documented below.  Note that not all transmit
  policies may be 802.3ad compliant, particularly in
  regards to the packet mis-ordering requirements of
  section 43.2.4 of the 802.3ad standard.  Differing
  peer implementations will have varying tolerances for
  noncompliance.

  Prerequisites:

  1. Ethtool support in the base drivers for retrieving
  the speed and duplex of each slave.

  2. A switch that supports IEEE 802.3ad Dynamic link
  aggregation.

  Most switches will require some type of configuration
  to enable 802.3ad mode.

 balance-tlb or 5

  Adaptive transmit load balancing: channel bonding that
  does not require any special switch support.

  In tlb_dynamic_lb=1 mode; the outgoing traffic is
  distributed according to the current load (computed
  relative to the speed) on each slave.

  In tlb_dynamic_lb=0 mode; the load balancing based on
  current load is disabled and the load is distributed
  only using the hash distribution.

  Incoming traffic is received by the current slave.
  If the receiving slave fails, another slave takes over
  the MAC address of the failed receiving slave.

  Prerequisite:

  Ethtool support in the base drivers for retrieving the
  speed of each slave.

 balance-alb or 6

  Adaptive load balancing: includes balance-tlb plus
  receive load balancing (rlb) for IPV4 traffic, and
  does not require any special switch support.  The
  receive load balancing is achieved by ARP negotiation.
  The bonding driver intercepts the ARP Replies sent by
  the local system on their way out and overwrites the
  source hardware address with the unique hardware
  address of one of the slaves in the bond such that
  different peers use different hardware addresses for
  the server.

  Receive traffic from connections created by the server
  is also balanced.  When the local system sends an ARP
  Request the bonding driver copies and saves the peer's
  IP information from the ARP packet.  When the ARP
  Reply arrives from the peer, its hardware address is
  retrieved and the bonding driver initiates an ARP
  reply to this peer assigning it to one of the slaves
  in the bond.  A problematic outcome of using ARP
  negotiation for balancing is that each time that an
  ARP request is broadcast it uses the hardware address
  of the bond.  Hence, peers learn the hardware address
  of the bond and the balancing of receive traffic
  collapses to the current slave.  This is handled by
  sending updates (ARP Replies) to all the peers with
  their individually assigned hardware address such that
  the traffic is redistributed.  Receive traffic is also
  redistributed when a new slave is added to the bond
  and when an inactive slave is re-activated.  The
  receive load is distributed sequentially (round robin)
  among the group of highest speed slaves in the bond.

  When a link is reconnected or a new slave joins the
  bond the receive traffic is redistributed among all
  active slaves in the bond by initiating ARP Replies
  with the selected MAC address to each of the
  clients. The updelay parameter (detailed below) must
  be set to a value equal or greater than the switch's
  forwarding delay so that the ARP Replies sent to the
  peers will not be blocked by the switch.

  Prerequisites:

  1. Ethtool support in the base drivers for retrieving
  the speed of each slave.

  2. Base driver support for setting the hardware
  address of a device while it is open.  This is
  required so that there will always be one slave in the
  team using the bond hardware address (the
  curr_active_slave) while having a unique hardware
  address for each slave in the bond.  If the
  curr_active_slave fails its hardware address is
  swapped with the new curr_active_slave that was
  chosen.

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