Bonding on debian

apt-get install ifenslave-2.6

Then add following to /etc/network/interfaces:
auto bond0
iface bond0 inet static
address 10.12.12.163
netmask 255.255.255.0
network 10.12.12.0
gateway 10.12.12.254
slaves eth0 eth1
bond_mode active-backup
bond_miimon 100
bond_downdelay 200
bond_updelay 200

Now just bring the interface up!


NOTE:
For Etch, you need to add the following lines to /etc/modprobe.d/arch/i386

alias bond0 bonding
options bonding mode=1 miimon=100 downdelay=200 updelay=200

Don't forget to run update-modules & bring up the interface!