bonding mode 1 works as designed. Or not?

Heiko Gerstung
2006-02-14T21:38:05Z

Hi, there!

I just set up bonding for a 2.6.12 box in active-backup mode (mode 1)
and found out that every packet is duplicated, despite the fact that the
documentation (Documentation/network/bonding.txt) says:

"active-backup or 1
Active-backup policy: Only one slave in the bond is
active. A different slave becomes active if, and only
if, the active slave fails. The bond's MAC address is
externally visible on only one port (network adapter)
to avoid confusing the switch. This mode provides
fault tolerance. The primary option affects the
behavior of this mode."

My understanding of this mode is:
eth0 and eth1 are in a bonding group, mode=1, miimon=100 ... eth0 is the
active slave and used as long as the physical link is available (checked
by using MII monitoring), at the same time eth1 is totally passive,
neither passing any received packets to the kernel nor sending packets,
if the kernel wants it to do so. As soon as the eth0 link status changes
to "down", eth1 is activated and used, and now eth0 remains silent and
deaf until it becomes the active slave again.

Any comments on that? Is the documentation wrong OR is there a bug in
the implementation of the bonding module?

Thank you in advance,
kind regards,

Heiko