apt-get install ifenslave
Then edit /etc/modprobe.d/arch/i386:
alias bond0 bonding
options bonding mode=2 miimon=100 downdelay=200 updelay=200
Then edit the file /etc/network/interfaces and insert something like the following (as a replacement for the configuration of eth0 that you might currently be using). Note that XX:XX:XX:XX:XX:XX must be replaced by the hardware address of one of the interfaces that are being bonded or by a locally administered address.
iface bond0 inet static
pre-up modprobe bond0
hwaddress ether 00:02:55:E1:36:32
slaves eth0 eth1
The special file /proc/net/bonding/bond0 can be used to view the current configuration of the bond0 device.