Re: [PATCHv3 net 1/3] bonding: set AD_RX_PORT_DISABLED when disabling a port

[Hangbin Liu]

Hi Jay,

Any comments for this?

Thanks
Hangbin
On Fri, Feb 27, 2026 at 06:21:20AM +0000, Hangbin Liu wrote:
> > 	Such a backup interface is typically carrier up and able to send
> > or receive packets.  The peer generally won't send packets to the backup
> > interface, however, as no traffic is sent from the backup, and the MAC
> > for the bond uses a different interface, so no forwarding entries will
> > direct to the backup interface.
> > 
> > 	There are a couple of special cases, like LLDP, that are handled
> > as an exception, but in general, if a peer does send packets to the
> > backup interface (due to a switch flood, for example), they're dropped.
> 
> OK, this makes sense to me.
> 
> > 
> > >> 	Where I'm going with this is that, when multiple aggregator
> > >> support was originally implemented, the theory was to keep aggregators
> > >> other than the active agg in a state such that they could be put into
> > >> service immediately, without having to do LACPDU exchanges in order to
> > >> transition into the appropriate state.  A hot standby, basically,
> > >> analogous to an active-backup mode backup interface with link state up.
> > >
> > >This sounds good. But without LACPDU exchange, the hot standby actor and
>                          ^^ I mean with LACPDU exchange..
> > >partner should be in collecting/distributing state. What should we do when
> > >partner start send packets to us?
> > 
> > 	Did you mean "should not be in c/d state" above?  I.e., without
> > LACPDU exchage, ... not in c/d state?
> > 
> > 	Regardless, as above, the situation is generally equivalent to a
> > backup interface in active-backup mode: incoming traffic that isn't a
> > special case is dropped.  Normal traffic (bearing the bond source MAC)
> > isn't sent, as that would update the peer's forwarding table.
> > 
> > 	Nothing in the standard prohibits us from having multiple
> > aggregators in c/d state simultaneously.  A configuration with two
> > separate bonds, each with interfaces successfully aggregated together
> > with their respective peers, wherein those two bonds are placed into a
> > third bond in active-backup mode is essentially the same thing as what
> > we're discussing.
> 
> In theory this looks good. But in fact, when we do failover and set the
> previous active port to disabled via
>   - __disable_port(port)
>     - slave->rx_disabled = 1
> 
> This will stop the failover port back to c/d state. For example, in my
> testing (see details in patch 03), we have 4 ports, eth0, eth1, eth2, eth3.
> eth0 and eth1 are agg1, eth2 and eth3 are agg2. If we do failover on eth1,
> when eth1 come up, the final state will be:
> 
> 3: eth0@if3: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc noqueue master bond0 state UP mode DEFAULT group default qlen 1000
>     bond_slave state BACKUP ad_aggregator_id 1 ad_actor_oper_port_state_str <active,short_timeout,aggregating,in_sync,collecting,distributing> ad_partner_oper_port_state_str <active,short_timeout,aggregating,in_sync,collecting,distributing> actor_port_prio 10
> 
> 4: eth1@if4: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc noqueue master bond0 state UP mode DEFAULT group default qlen 1000
>     bond_slave state BACKUP ad_aggregator_id 1 ad_actor_oper_port_state_str <active,short_timeout,aggregating> ad_partner_oper_port_state_str <active,short_timeout,aggregating,in_sync> actor_port_prio 255
> 
> 5: eth2@if3: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc noqueue master bond0 state UP mode DEFAULT group default qlen 1000
>     bond_slave state ACTIVE ad_aggregator_id 2 ad_actor_oper_port_state_str <active,short_timeout,aggregating,in_sync,collecting,distributing> ad_partner_oper_port_state_str <active,short_timeout,aggregating,in_sync,collecting,distributing> actor_port_prio 1000
> 
> 6: eth3@if4: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc noqueue master bond0 state UP mode DEFAULT group default qlen 1000
>     bond_slave state ACTIVE ad_aggregator_id 2 ad_actor_oper_port_state_str <active,short_timeout,aggregating,in_sync,collecting,distributing> ad_partner_oper_port_state_str <active,short_timeout,aggregating,in_sync,collecting,distributing> actor_port_prio 255
> 
> 7: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
>     bond mode 802.3ad actor_port_prio ad_aggregator 2
> 
> So you can see the eth0 state is c/d, while eth1 state is active, aggregating.
> Do you think it's a correct state?
> 
> Thanks
> Hangbin