Hi, I've using linux bonding in active-backup mode to combine two pairs of GigE NICs (eth0/eth1, eth2/eth3) into two logical bonds (bond0/bond1). All is working fine. However, I would like to specify a primary interface for each bond. This means I need to specify different options to the bonding module for each bond. I have tried every conceivable incantation of options and cannot get the kernel to recognize the second set of options. Initially, my modprobe.conf looked like this: alias bond0 bonding alias bond1 bonding options bonding mode=active-backup miimon=100 max_bonds=2 What I am trying to achieve should be possible by changing modprobe.conf to this: alias bond0 bonding options bond0 -o bond0 miimon=100 mode=active-backup primary=eth0 alias bond1 bonding options bond1 -o bond1 miimon=100 mode=active-backup primary=eth2 But this results in fatal errors while bringing up the bonding interfaces. Changing to this eliminates the errors, but bond1 ignores the different options: alias bond0 bonding options bond0 -o bond0 miimon=100 mode=active-backup primary=eth0 max_bonds=1 alias bond1 bonding options bond1 -o bond1 miimon=100 mode=active-backup primary=eth2 max_bonds=1 I have tried many other combinations as well: install bond1 /sbin/modprobe --ignore-install bonding -o bond1 mode=active-backup primary=eth2 Nothing works. I also came across this note in the bonding docs: "NOTE: It has been observed that some Red Hat supplied kernels are apparently unable to rename modules at load time (the "-o bond1" part). Attempts to pass that option to modprobe will produce an "Operation not permitted" error. This has been reported on some Fedora Core kernels, and has been seen on RHEL 4 as well. On kernels exhibiting this problem, it will be impossible to configure multiple bonds with differing parameters." I have seen that error as well with certain combinations of options in my modprobe.conf. Am I simply out of luck here? Does anyone know of a solution? Thanks.