Bug#870633: ifenslave: Option bond-mode does not work

[bkw+1517636960]

Wanted to follow up.  I can confirm that the following content in 
/etc/modprobe.d/bonding.conf works (for me).  If it isn't clear to 
others reading this, enp0s20f0 is the name of primary network interface.

alias bond0 bonding
options bonding mode=active-backup miimon=100 primary=enp0s20f0
In /etc/network/interfaces, I have commented (disabled):

bond-mode active-backup
bond-miimon 100