auto lo
iface lo inet loopback

 auto bond0
 iface bond0 inet static
     bond_miimon  100
     bond_mode balance-rr
     address  xxx.xxx.xxx.xxx
     netmask  xxx.xxx.xxx.xxx
#     network  xxx.xxx.xxx.xxx
     broadcast xxx.xxx.xxx.xxx
     gateway  xxx.xxx.xxx.xxx
     dns-nameservers xxx.xxx.xxx.xxx
     up /sbin/ifenslave bond0 eth0 eth1
     down /sbin/ifenslave -d bond0 eth0 eth1