[ovs-dev] [PATCH 2/2] bond: Sending learning packets on active-backup.

[Ethan Jackson]

Thanks, I merged this.

Ethan

On Thu, Jul 5, 2012 at 2:54 PM, Ben Pfaff <blp at nicira.com> wrote:
> Beautiful.
>
> On Thu, Jul 05, 2012 at 02:30:55PM -0700, Ethan Jackson wrote:
>> How about this?
>>
>>     bond: Sending learning packets on active-backup.
>>
>>     Suppose we have an active bond with two ports, eth1 and eth2,
>>     attached to a standard L2 learning switch which does not know it's
>>     participating in a bond (i.e. isn't running LACP).  Suppose eth1 is
>>     active and therefore the L2 learning switch is forwarding traffic
>>     to eth1 as instructed by its learning table.  Now suppose, for some
>>     reason, OVS fails over from eth1 to eth2.  For each destination
>>     MAC, the L2 learning switch will continue sending traffic to eth1,
>>     which will be dropped, until either traffic from that MAC appears
>>     on eth2, or the learning table entries expire.
>>
>>     To alleviate this issue, this patch sends learning packets on newly
>>     active interfaces in active-backup bonds in order to educate the
>>     upstream network of the change.
>>
>>     Requested-by: Frido Roose <fr.roose at gmail.com>
>>     Signed-off-by: Ethan Jackson <ethan at nicira.com>
>>
>> Ethan
>>
>> On Mon, Jun 25, 2012 at 4:41 PM, Ben Pfaff <blp at nicira.com> wrote:
>> > On Mon, Jun 25, 2012 at 03:51:30PM -0700, Ethan Jackson wrote:
>> >> When an active-backup bond fails over, it makes sense to update
>> >> upstream learning tables of the change so that traffic is forwarded
>> >> to the correct slave.
>> >>
>> >> Requested-by: Frido Roose <fr.roose at gmail.com>
>> >> Signed-off-by: Ethan Jackson <ethan at nicira.com>
>> >
>> > The patch looks fine but I'd really like a more spelled out rationale
>> > in the commit message.  Otherwise a year from now when I read the
>> > commit I won't know why it makes sense.
>> >
>> > Thanks,
>> >
>> > Ben.