Linux Ethernet Bridging - May 2009 - [Bridge] brigde does not relay BPDU multicast pkgs

Hi List

We have noticed that when STP is off in the linux bridge, it won't
relay STP pkts received from other bridges.
This feels like a bug(a bad one too). I hope this isn't
intentional behaviour?

 Jocke

On Fri, May 08, 2009 at 10:33:37AM +0200, Joakim Tjernlund
wrote:
> We have noticed that when STP is off in the linux bridge, it won't
> relay STP pkts received from other bridges.
> This feels like a bug(a bad one too). I hope this isn't
> intentional behaviour?
IEEE 802.1D specifies that no bridge should ever forward packets
destined to the bridge multicast groups.  See requirement 7.12.6 in
802.1D-2004.

-- 
Ross Vandegrift
ross at kallisti.us

"If the fight gets hot, the songs get hotter.  If the going gets tough,
the songs get tougher."
	--Woody Guthrie

On Fri, 8 May 2009 10:33:37 +0200
Joakim Tjernlund <joakim.tjernlund at transmode.se> wrote:
> 
> Hi List
> 
> We have noticed that when STP is off in the linux bridge, it won't
> relay STP pkts received from other bridges.
> This feels like a bug(a bad one too). I hope this isn't
> intentional behaviour?
> 
>  Jocke
> 
> _______________________________________________
> Bridge mailing list
> Bridge at lists.linux-foundation.org
> https://lists.linux-foundation.org/mailman/listinfo/bridge
It is a debatable whether this is correct behaviour.
My current opinion is that it needs to forward STP packets if
STP is off. This would allow for loop detection by other bridges
doing STP.

Longer term, RSTP needs to be fully integrated and default to on.
That way the average user will be safe from loops.

--

Joakim Tjernlund/Transmode wrote on 10/05/2009 19:47:19:
>
> Stephen Hemminger <shemminger at vyatta.com> wrote on 08/05/2009
18:02:26:
>
> > On Fri, 8 May 2009 10:33:37 +0200
> > Joakim Tjernlund <joakim.tjernlund at transmode.se> wrote:
> >
> > >
> > > Hi List
> > >
> > > We have noticed that when STP is off in the linux bridge, it
won't
> > > relay STP pkts received from other bridges.
> > > This feels like a bug(a bad one too). I hope this isn't
> > > intentional behaviour?
> > >
> > >  Jocke
> > >
> > > _______________________________________________
> > > Bridge mailing list
> > > Bridge at lists.linux-foundation.org
> > > https://lists.linux-foundation.org/mailman/listinfo/bridge
> >
> > It is a debatable whether this is correct behaviour.
> > My current opinion is that it needs to forward STP packets if
> > STP is off. This would allow for loop detection by other bridges
> > doing STP.
>
> Exactly, I had a look at the bride code and it wasn't obvious
> too me where to add the code to make this happen. Any pointers?
Looking into this I got a question:
Should the bridge forward the whole bridge multicast group except PAUSE
or only the STP multicast address?

 Jocke