Red Hat ENTERPRISE LINUX 5 - DEPLOYMENT Deployment Manual page 605

• If no slaves are active, the first slave to recover is made the active slave.
• When initially enslaved, the primary slave is always made the active slave.
Changing the primary_reselect policy via sysfs will cause an immediate selection of the
best active slave according to the new policy. This may or may not result in a change of the active
slave, depending upon the circumstances
updelay=<time_in_milliseconds>
Specifies (in milliseconds) how long to wait before enabling a link. The value must be a multiple of
the value specified in the miimon parameter. The value is set to 0 by default, which disables it.
use_carrier=<number>
Specifies whether or not miimon should use MII/ETHTOOL ioctls or netif_carrier_ok()
to determine the link state. The netif_carrier_ok() function relies on the device driver to
maintains its state with netif_carrier_on/off; most device drivers support this function.
The MII/ETHROOL ioctls tools utilize a deprecated calling sequence within the kernel. However,
this is still configurable in case your device driver does not support netif_carrier_on/off.
Valid values are:
• 1 — Default setting. Enables the use of netif_carrier_ok().
• 0 — Enables the use of MII/ETHTOOL ioctls.
Tip
If the bonding interface insists that the link is up when it should not be, it is possible
that your network device driver does not support netif_carrier_on/off.
xmit_hash_policy=<value>
Selects the transmit hash policy used for slave selection in balance-xor and 802.3ad modes.
Possible values are:
• 0 or layer2 — Default setting. This option uses the XOR of hardware MAC addresses to
generate the hash. The formula used is:
(<source_MAC_address> XOR <destination_MAC>) MODULO <slave_count>
This algorithhm will place all traffic to a particular network peer on the same slave, and is
802.3ad compliant.
• 1 or layer3+4 — Uses upper layer protocol information (when available) to generate the hash.
This allows for traffic to a particular network peer to span multiple slaves, although a single
connection will not span multiple slaves.
The formula for unfragmented TCP and UDP packets used is:
((<source_port> XOR <dest_port>) XOR
((<source_IP> XOR <dest_IP>) AND 0xffff)
MODULO <slave_count>
The Channel Bonding Module
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