On Fri, Apr 29, 2011 at 11:17:48AM +0800, WeipingPan wrote:

On 04/28/2011 08:21 PM, Neil Horman wrote:

quoted

On Thu, Apr 28, 2011 at 03:33:50PM +0800, WeipingPan wrote:

quoted

Hi, all,

802.3ad mode in bonding implements 802.3ad standard.

I am just wondering  802.3ad mode is useful,
since  bonding has many modes like balance-rr, active-backup, etc.

Yes, of course its usefull.  For switches which support 802.3ad, this mode
allows for both peers to understand that the links in the bond are acting as an
aggregate, which makes it easier to prevent things like inadvertently looped
back frames, for which the other modes have to have all sorts of hacks to
prevent.

What is looped back frames here ?

In this case they are frames that get received by the bond, which the bond
itself sent.  In modes where more than one slave is active, and in which the
switch has no additional knoweldge of the aggregate (e.g. round robin mode), the
bond can send a frame on one slave, which the switch may broadcast to all ports,
causing the frame just sent by the bond to then get received on another slave.

I didn't see any special code to handle looped back frames in other
modes in bonding,
can you take an example ?

See bond_handle_frame.

Neil

thanks
Weiping Pan

quoted

Neil