[rbridge] Consensus Check: Configure ports to disable end stationtraffic

[Anoop Ghanwani]

If the network operator decides that a link should
never have end stations on it, and if an end station
ends up there, then that is a misconfiguration
and I think it would be OK for the end station 
to not be reachable in that case.

BTW, even if the end station annouced itself,
configuring the link per Donald's message would
have prevented us from reaching that station.
In other words, this problem will happen regardless
of the protocol in operation.

If we don't allow the optimization, the spec will
require that RBridges flood copies of all frames
on all links.

This is a configuration optimization which I think
is essential and which, even if not provided by 
the spec, will most likely be provided by
implementations.

Anoop

> -----Original Message-----
> From: Joe Touch [mailto:touch at ISI.EDU] 
> Sent: Monday, January 07, 2008 11:32 AM
> To: Anoop Ghanwani
> Cc: Eastlake III Donald-LDE008; Rbridge at postel.org
> Subject: Re: [rbridge] Consensus Check: Configure ports to 
> disable end stationtraffic
> 
> I'm concerned about the case where an end station moves and 
> doesn't announce itself. There's no requirement in ethernet 
> to do so, and such a station would never be discovered if we 
> don't flood broadcast to all links.
> 
> I.e., the optimization below is a recipe for ARP failure in 
> such cases. 
> I disagree with it.
> 
> Joe
> 
> Anoop Ghanwani wrote:
> > This certainly makes sense is what I tend to
> > think of as a TRILL "core" port.   On such a 
> > port, we would never see non-TRILL encap'ed frames (other than the 
> > usual exceptions such as BPDUs and other link layer control 
> traffic).
> > 
> > I wonder if it makes sense to also have a configuration for a TRILL 
> > "edge" port -- one where we are configured to never send TRILL 
> > encap'ed traffic because we don't intend for it to be used as a 
> > transit link (even though connectivity may exist to another RBridge 
> > for redundancy purposes).
> > 
> > Anoop
> > 
> >> -----Original Message-----
> >> From: rbridge-bounces at postel.org
> >> [mailto:rbridge-bounces at postel.org] On Behalf Of Eastlake III
> >> Donald-LDE008
> >> Sent: Monday, January 07, 2008 10:34 AM
> >> To: Rbridge at postel.org
> >> Subject: [rbridge] Consensus Check: Configure ports to disable end 
> >> stationtraffic
> >>
> >> This is a check via the mailing list to confirm or refute 
> an apparent 
> >> consensus at the Vancouver meeting taken from the minutes of that
> >> meeting:
> >>
> >>            Currently broadcast, unknown unicast, and
> >>       non-IP-derived multicast frames are output to all 
> links. This is
> >>       wasteful if there are no end stations on the link. 
> Provide that
> >>       a port can be configured so as to be disabled for end station
> >>       traffic.
> >>
> >> If no particular controversy arises over this in the next three 
> >> weeks, We will declare it to be the working group consensus.
> >>
> >> Thanks,
> >> Donald & Erik
> >>
> >> _______________________________________________
> >> rbridge mailing list
> >> rbridge at postel.org
> >> http://mailman.postel.org/mailman/listinfo/rbridge
> >>
> > 
> > _______________________________________________
> > rbridge mailing list
> > rbridge at postel.org
> > http://mailman.postel.org/mailman/listinfo/rbridge
> 
> 
>