Below is the method I personally found to work reliably:

apt-get install ifenslave
echo "bonding" >> /etc/modules
modprobe bonding
ifdown eth0

edit /etc/network/interfaces, changing “eth0″ (or your configured NIC) to “bond0″, and replacing “allow-hotplug” with “auto”.  The following sed line give you this automagically:

sed 's/eth0/bond0/;s/allow-hotplug bond0/auto bond0/' </etc/network/interfaces

Tell ifup and ifdown to add/remove devices to bond0 lines:

echo " up /sbin/ifenslave      bond0 eth0 eth1" >> /etc/network/interfaces
echo " down /sbin/ifenslave -d bond0 eth0 eth1" >> /etc/network/interfaces
ifup bond0;

And you’re done!

You can add all the options for the bonding module to the line in /etc/modules, like:

echo "bonding mode=1 miimon=250 primary=eth0" >> /etc/modules;

Details of all options available at linuxfoundation.org