Re: CenturyLink RCA?

[Eric Loos <eric () ipergy net>]

This seems entirely plausible given that DWDM amplifiers and lasers being a complex analog system, they need OOB to 
align. 

--
Eric

> On 31 Dec 2018, at 16:06, Saku Ytti <saku () ytti fi> wrote:
>
> Hey Steve,
>
> I will continue to speculate, as that's all we have.
>
> > 1.  Are you telling me that several line cards failed in multiple cities in the same way at the same time?  Don't 
> > think so unless the same software fault was propagated to all of them.  If the problem was that they needed to be 
> > reset, couldn't that be accomplished by simply reseating them?
>
> L2 DCN/OOB, whole network shares single broadcast domain
>
> > 2.  Do we believe that an OOB management card was able to generate so much traffic as to bring down the optical 
> > switching?  Very doubtful which means that the systems were actually broken due to trying to PROCESS the "invalid 
> > frames".  Seems like very poor control plane management if the system is attempting to process invalid data and 
> > bringing down the forwarding plane.
>
> L2 loop. You will kill your JNPR/CSCO with enough trash on MGMT ETH.
> However I can be argued that optical network should fail up in absence
> of control-plane, IP network has to fail down.
>
> > 3.  In the cited document it was stated that the offending packet did not have source or destination information.  
> > If so, how did it get propagated throughout the network?
>
> BPDU
>
> > My guess at the time and my current opinion (which has no real factual basis, just years of experience) is that a 
> > bad software package was propagated through their network.
>
> Lot of possible reasons, I choose to believe what they've communicated
> is what the writer of the communication thought that happened, but as
> they likely are not SME it's broken radio communication. BCAST storm
> on L2 DCN would plausibly fit the very ambiguous reason offered and is
> something people actually are doing.
>
> -- 
>  ++ytti