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 <s...@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
