[ovs-discuss] Query about active-backup mode in lacp

[kunapaneni prashanth]

Hi,
 I have question regarding how active port is selected when bond port
in configured in active-backup. port priority seem to have no effect
on active port selection.

I configured bond port as follows

"ovs-vsctl add-bond br0 bond0 poct0 poct1 bond_mod=active-backup lacp=active
other_config:lacp-time=fast"

and i can see its up

~ # ovs-appctl bond/show bond0
---- bond0 ----
bond_mode: active-backup
bond may use recirculation: no, Recirc-ID : -1
bond-hash-basis: 0
updelay: 0 ms
downdelay: 0 ms
lacp_status: negotiated

slave poct0: enabled
    may_enable: true

slave poct1: enabled
    active slave
    may_enable: true



Now the question, here poct1 is selected as the interface to forward
traffic. But how is this selection made.

i tried to configure the port priority, but port priority is not taken
into consideration.
If i change the port priority of the current active interface, active
interface gets switched. Is this expected behaviour? shouldn't
selection be always based on priority


Here is the behaviour

I change poct1 priority, active interface switches to poct0

~ # ovs-vsctl set interface poct1 other_config:lacp-port-priority=5
~ #
~ # ovs-appctl bond/show bond0
---- bond0 ----
bond_mode: active-backup
bond may use recirculation: no, Recirc-ID : -1
bond-hash-basis: 0
updelay: 0 ms
downdelay: 0 ms
lacp_status: negotiated

slave poct0: enabled
    active slave
    may_enable: true

slave poct1: enabled
    may_enable: true


Now i change priority of poct0, active interface switches to poct1


~ # ovs-vsctl set interface poct0 other_config:lacp-port-priority=4
~ #
~ #
~ # ovs-appctl bond/show bond0
---- bond0 ----
bond_mode: active-backup
bond may use recirculation: no, Recirc-ID : -1
bond-hash-basis: 0
updelay: 0 ms
downdelay: 0 ms
lacp_status: negotiated

slave poct0: enabled
    may_enable: true

slave poct1: enabled
    active slave
    may_enable: true



Please clarify

Thanks,
Prashanth