Bonding · mike

See https://www.kernel.org/doc/Documentation/networking/bonding.txt

For the slave interfaces, set each of their network configs as such, noting the last 2 lines:

DEVICE="eth0"
HWADDR="xx:xx:xx:xx:xx:xx"
ONBOOT="yes"
TYPE="Ethernet"
UUID="xxxxxx"
NM_CONTROLLED=no
SLAVE=yes
MASTER=bond0

And the master as such

DEVICE="bond0"
IPV6INIT="no"
MTU="1500"
ONBOOT="yes"
NM_CONTROLLED=no
BOOTPROTO=static
IPADDR=xxx.xxx.xxx.xxx
NETMASK=xxx.xxx.xxx.xxx
GATEWAY=xxx.xxx.xxx.xxx
BONDING_OPTS="mode=1 miimon=100"

The bonding config option mode=1 enables Active-Standby mode

The bonding config option miimon=100 polls the interfaces every 100ms too see if one has gone down and to fail over if necessary.

The documentation says:

miimon

    Specifies the MII link monitoring frequency in milliseconds.
    This determines how often the link state of each slave is
    inspected for link failures.  A value of zero disables MII
    link monitoring.  A value of 100 is a good starting point.
    The use_carrier option, below, affects how the link state is
    determined.  See the High Availability section for additional
    information.  The default value is 0.

Therefore, by default, if one interface goes down, the bonded interface won’t realise and will continue to try sing it!