[rbridge] MUST not send spanning tree BPDUs?

[Anoop Ghanwani]

I agree about the "MUST NOT forward BPDUs" part.

However, I think it should always be legal for an
RBridge to generate BDPUs (although not a requirement).
In many cases, this can help with loop detection
on access ports.

Anoop

> -----Original Message-----
> From: rbridge-bounces at postel.org 
> [mailto:rbridge-bounces at postel.org] On Behalf Of Radia Perlman
> Sent: Friday, November 28, 2008 9:37 PM
> To: Donald Eastlake
> Cc: rbridge at postel.org
> Subject: Re: [rbridge] MUST not send spanning tree BPDUs?
> 
> Yeah. I think we should either drop the sentence, or say "MAY 
> generate 
> BPDUs,
> but MUST NOT forward BPDUs from
> one link to another".
> 
> Radia
> 
> Donald Eastlake wrote:
> > Hi Radia,
> >
> > See below...
> >
> > On Fri, Nov 28, 2008 at 6:31 PM, Radia Perlman 
> <Radia.Perlman at sun.com> wrote:
> >   
> >> The spec currently says (in section 4.7.3.3 Transmission of BPDUs)
> >>
> >>  RBridges MAY support a capability for sending spanning 
> tree BPDUs for
> >>   the purpose of attempting to force a bridged LAN to partition as
> >>   discussed in Section A.3.3.  Except for this optional capability,
> >>   RBridges MUST NOT send spanning tree BPDUs.
> >>
> >>
> >> I don't remember any discussion on saying that RBridges 
> MUST NOT send
> >> BPDUs. I remember
> >> at one point requiring it, and saying that an RBridge is 
> DRB if and only
> >> if it is the Spanning tree Root.
> >> (I still would prefer that, by the way -- makes all the 
> controversial
> >> per VLAN Hellos
> >> unnecessary).
> >>
> >> I remember it being removed from the spec (because of 
> complexity with n
> >> versions of
> >> spanning tree, and links with no bridges, perhaps, where 
> the spanning
> >> tree messages would
> >> be unnecessary overhead), but I don't remember any reason to say
> >> RBridges MUST NOT sent
> >> BPDUs.
> >>     
> >
> > I suspect it used to say "do not" in the sense that there is no
> > RBridge reason for an RBridge port to send spanning tree 
> BPDUs except
> > for the optional bridge LAN partitioning feature described 
> in Section
> > A.3.3. In some pass to upgrade to IETF implementation key words, it
> > probably got changed when it didn't necessarily need to be. The only
> > problem I can see with dropping this is that it might marginally
> > increase the chance someone would erroneously try to build spanning
> > trees through an RBridge.
> >
> > Donald
> >
> >   
> >> Anyone else remember?
> >>
> >> Thanks,
> >>
> >> Radia
> >> _______________________________________________
> >> rbridge mailing list
> >> rbridge at postel.org
> >> http://mailman.postel.org/mailman/listinfo/rbridge
> >>     
> > =============================
> >  Donald E. Eastlake 3rd   +1-508-634-2066 (home)
> >  155 Beaver Street
> >  Milford, MA 01757 USA
> >  d3e3e3 at gmail.com
> > _______________________________________________
> > rbridge mailing list
> > rbridge at postel.org
> > http://mailman.postel.org/mailman/listinfo/rbridge
> >   
> 
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