Merge branch 'intelfb-patches' of master.kernel.org:/pub/scm/linux/kernel/git/airlied...

[pandora-kernel.git] / Documentation / networking / bonding.txt

diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.txt
index afac780..dc942ea 100644 (file)
--- a/Documentation/networking/bonding.txt
+++ b/Documentation/networking/bonding.txt
@@ -192,6 +192,17 @@ or, for backwards compatibility, the option value.  E.g.,
 arp_interval
 
        Specifies the ARP link monitoring frequency in milliseconds.
 arp_interval
 
        Specifies the ARP link monitoring frequency in milliseconds.

+
+       The ARP monitor works by periodically checking the slave
+       devices to determine whether they have sent or received
+       traffic recently (the precise criteria depends upon the
+       bonding mode, and the state of the slave).  Regular traffic is
+       generated via ARP probes issued for the addresses specified by
+       the arp_ip_target option.
+
+       This behavior can be modified by the arp_validate option,
+       below.
+

        If ARP monitoring is used in an etherchannel compatible mode
        (modes 0 and 2), the switch should be configured in a mode
        that evenly distributes packets across all links. If the
        If ARP monitoring is used in an etherchannel compatible mode
        (modes 0 and 2), the switch should be configured in a mode
        that evenly distributes packets across all links. If the


@@ -213,6 +224,54 @@ arp_ip_target
        maximum number of targets that can be specified is 16.  The
        default value is no IP addresses.
 
        maximum number of targets that can be specified is 16.  The
        default value is no IP addresses.
 

+arp_validate
+
+       Specifies whether or not ARP probes and replies should be
+       validated in the active-backup mode.  This causes the ARP
+       monitor to examine the incoming ARP requests and replies, and
+       only consider a slave to be up if it is receiving the
+       appropriate ARP traffic.
+
+       Possible values are:
+
+       none or 0
+
+               No validation is performed.  This is the default.
+
+       active or 1
+
+               Validation is performed only for the active slave.
+
+       backup or 2
+
+               Validation is performed only for backup slaves.
+
+       all or 3
+
+               Validation is performed for all slaves.
+
+       For the active slave, the validation checks ARP replies to
+       confirm that they were generated by an arp_ip_target.  Since
+       backup slaves do not typically receive these replies, the
+       validation performed for backup slaves is on the ARP request
+       sent out via the active slave.  It is possible that some
+       switch or network configurations may result in situations
+       wherein the backup slaves do not receive the ARP requests; in
+       such a situation, validation of backup slaves must be
+       disabled.
+
+       This option is useful in network configurations in which
+       multiple bonding hosts are concurrently issuing ARPs to one or
+       more targets beyond a common switch.  Should the link between
+       the switch and target fail (but not the switch itself), the
+       probe traffic generated by the multiple bonding instances will
+       fool the standard ARP monitor into considering the links as
+       still up.  Use of the arp_validate option can resolve this, as
+       the ARP monitor will only consider ARP requests and replies
+       associated with its own instance of bonding.
+
+       This option was added in bonding version 3.1.0.
+

 downdelay
 
        Specifies the time, in milliseconds, to wait before disabling
 downdelay
 
        Specifies the time, in milliseconds, to wait before disabling