lagg+vlan+igb kernel bug

Eugene Grosbein egrosbein at rdtc.ru
Mon Apr 29 12:11:10 UTC 2013


On 29.04.2013 16:24, Eugene Grosbein wrote:
> Hi!
> 
> Today I discovered really subtle bug in connection of lagg(4), vlan(4) and igb(4) drivers.
> 
> Here is what I have in /etc/rc.conf:
> 
> cloned_interfaces="lagg0 lagg1"
> ifconfig_lagg1="laggproto lacp laggport igb0 laggport igb1"
> #ifconfig_lagg1_alias0="link 00:1b:21:63:5b:d1"
> ifconfig_igb0="-wol"
> ifconfig_igb1="-wol"
> 
> My lagg1 has no IP addresses but lots of vlans created on it.
> These vlans carry PPPoE frames only. This configuration works just fine.
> 
> But, it I uncomment the line changing MAC-address of lagg1 (ifconfig_lagg1_alias0),
> I still have igb0 working just fine (input/output/broadcast/unicast - all OK)
> but igp1 stops accepting unicasts.
> 
> More precisely: if I bring igb0 link down, lagg1 excludes it from aggregation group,
> then tcpdump -ni igb1 shows that no unicasts come in, broadcasts only.
> 
> I use switch port mirroring feature to make sure that switch directs unicasts to igb1.
> 
> However, if I manually recreate lagg1 and assign MAC to lagg1 first and
> assign igb0/igb1 later, both ports run just fine and this issue does not rise.
> 
> It seems, lagg(4) fails to reprogramm igb1 with new MAC in first case?
> In both cases, ifconfig shows single MAC address for lagg1 and both its ports.

Forgot to mention, I use 8.3-STABLE/amd64 with dual-port 82576 adapter 
and stock igb(4) driver version 2.3.1.

Eugene Grosbein





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