Subject: Re: [BUG] bonded interfaces drop bpdu (stp) frames

From: Jay Vosburgh <[email-masked]>
Date: Thu, 12 Jul 2018 10:51:58 -0400

Mahesh Bandewar (महेश बंडेवार) wrote:

>On Wed, Jul 11, 2018 at 3:23 PM, Michal Soltys <[email-masked]> wrote:
>>
>> Hi,
>>
>> As weird as that sounds, this is what I observed today after bumping
>> kernel version. I have a setup where 2 bonds are attached to linux
>> bridge and physically are connected to two switches doing MSTP (and
>> linux bridge is just passing them).
>>
>> Initially I suspected some changes related to bridge code - but quick
>> peek at the code showed nothing suspicious - and the part of it that
>> explicitly passes stp frames if stp is not enabled has seen little
>> changes (e.g. per-port group_fwd_mask added recently). Furthermore - if
>> regular non-bonded interfaces are attached everything works fine.
>>
>> Just to be sure I detached the bond (802.3ad mode) and checked it with
>> simple tcpdump (ether proto \\stp) - and indeed no hello packets were
>> there (with them being present just fine on active enslaved interface,
>> or on the bond device in earlier kernels).
>>
>> If time permits I'll bisect tommorow to pinpoint the commit, but from
>> quick todays test - 4.9.x is working fine, while 4.16.16 (tested on
>> debian) and 4.17.3 (tested on archlinux) are failing.
>>
>> Unless this is already a known issue (or you have any suggestions what
>> could be responsible).
>>
>I believe these are link-local-multicast messages and sometime back a
>change went into to not pass those frames to the bonding master. This
>could be the side effect of that.

	Mahesh, I suspect you're thinking of:

commit b89f04c61efe3b7756434d693b9203cc0cce002e
Author: Chonggang Li <[email-masked]>
Date:   Sun Apr 16 12:02:18 2017 -0700

    bonding: deliver link-local packets with skb->dev set to link that packets arrived on

	Michal, are you able to revert this patch and test?

	-J

---
	-Jay Vosburgh, [email-masked]