Documentation/networking/bonding.rst

70    7.1	ARP Monitor Operation
71    7.2	Configuring Multiple ARP Targets
283 	Specifies the ARP link monitoring frequency in milliseconds.
285 	The ARP monitor works by periodically checking the slave
289 	generated via ARP probes issued for the addresses specified by
295 	If ARP monitoring is used in an etherchannel compatible mode
299 	fashion, all replies from the ARP targets will be received on
301 	fail.  ARP monitoring should not be used in conjunction with
302 	miimon.  A value of 0 disables ARP monitoring.  The default
307 	Specifies the IP addresses to use as ARP monitoring peers when
308 	arp_interval is > 0.  These are the targets of the ARP request
312 	address must be given for ARP monitoring to function.  The
318 	Specifies whether or not ARP probes and replies should be
320 	non-ARP traffic should be filtered (disregarded) for link
358 	Enabling validation causes the ARP monitor to examine the incoming
359 	ARP requests and replies, and only consider a slave to be up if it
360 	is receiving the appropriate ARP traffic.
362 	For an active slave, the validation checks ARP replies to confirm
365 	for backup slaves is on the broadcast ARP request sent out via the
368 	do not receive the ARP requests; in such a situation, validation
371 	The validation of ARP requests on backup slaves is mainly helping
381 	ARP monitor into considering the links as still up.  Use of
382 	validation can resolve this, as the ARP monitor will only consider
383 	ARP requests and replies associated with its own instance of
388 	Enabling filtering causes the ARP monitor to only use incoming ARP
393 	Filtering operates by only considering the reception of ARP
394 	packets (any ARP packet, regardless of source or destination) when
400 	ARP monitor into considering the links as still up.  Use of
401 	filtering can resolve this, as only ARP traffic is considered for
409 	in order for the ARP monitor to consider a slave as being up.
461 		interferes with the ARP monitor).
464 		the network must be updated via gratuitous ARP,
466 		often takes place for any traffic, not just ARP
469 		gratuitous ARP is lost, communication may be
475 		susceptible to loss of the gratuitous ARP, and an
577 		One gratuitous ARP is issued for the bonding master
658 		receive load balancing is achieved by ARP negotiation.
659 		The bonding driver intercepts the ARP Replies sent by
667 		is also balanced.  When the local system sends an ARP
669 		IP information from the ARP packet.  When the ARP
671 		retrieved and the bonding driver initiates an ARP
673 		in the bond.  A problematic outcome of using ARP
675 		ARP request is broadcast it uses the hardware address
679 		sending updates (ARP Replies) to all the peers with
689 		active slaves in the bond by initiating ARP Replies
693 		forwarding delay so that the ARP Replies sent to the
742 	notification (gratuitous ARP and unsolicited IPv6 Neighbor
1517    If ARP monitoring is enabled, it will disabled when MII
1520 To add ARP targets::
1529 To remove an ARP target::
1562 active-backup mode, using ARP monitoring, add the following lines to
1862 generated packets, for example, bonding's learning packets or ARP
1863 packets generated by either ALB mode or the ARP monitor mechanism, are
1911 monitoring a slave device's link state: the ARP monitor and the MII
1915 bonding driver itself, it is not possible to enable both ARP and MII
1918 7.1 ARP Monitor Operation
1921 The ARP monitor operates as its name suggests: it sends ARP
1927 The ARP monitor relies on the device driver itself to verify
1931 ARP monitor will immediately fail any slaves using that driver, and
1933 shows the ARP requests and replies on the network, then it may be that
1936 7.2 Configuring Multiple ARP Targets
1939 While ARP monitoring can be done with just one target, it can
1942 down or have a problem making it unresponsive to ARP requests.  Having
1943 an additional target (or several) increases the reliability of the ARP
1946 Multiple ARP targets must be separated by commas as follows::
1948  # example options for ARP monitoring with three targets
1954     # example options for ARP monitoring with one target
2005 receive/transmit times in the driver (needed by the ARP monitor), but
2009 The ARP monitor (and ARP itself) may become confused by this
2010 configuration, because ARP requests (generated by the ARP monitor)
2012 will arrive on a different interface (eth0).  This reply looks to ARP
2013 as an unsolicited ARP reply (because ARP matches replies on an
2250 failures, then either the MII or ARP monitors should work.  For
2252 end, the MII monitor has no direct means to detect this.  The ARP
2256 In general, however, in a multiple switch topology, the ARP
2260 the ARP monitor should be configured with multiple targets (at least
2262 regardless of which switch is active, the ARP monitor has a suitable
2272 switch, but this can be a viable alternative to the ARP monitor when using
2450 	therefore, the ARP monitor is not available in this mode.
2468 	network device driver of the slave interfaces, and the ARP
2487 support the use of the ARP monitor, and are thus restricted to using
2489 assurance as the ARP monitor).
2544 availability.  The ARP monitor will function in this topology, but its
2714 When an Ethernet Switch Module is in place, only the ARP