There is a guy who walks aroung Hyde Park Corner in London with a sandwich board that says "its going to get worse". Perhaps Ill go and talk to him next weekend and see what he thinks. -- Leigh --- original message --- From: "Warren Bailey" <wbailey@gci.com> Subject: Re: Solar Flux (was: Re: China prefix hijack) Date: 11th April 2010 Time: 9:14:50 pm Are we thinking its going to get worse?? Did anyone else see the intelsat spacecraft failure last week?? Sent using my GCI BlackBerry ----- Original Message ----- From: Valdis.Kletnieks@vt.edu <Valdis.Kletnieks@vt.edu> To: Michael Dillon <wavetossed@googlemail.com> Cc: Paul Vixie <vixie@isc.org>; Robert E. Seastrom <rs@seastrom.com>; nanog@merit.edu <nanog@merit.edu> Sent: Sun Apr 11 08:36:05 2010 Subject: Re: Solar Flux (was: Re: China prefix hijack) On Sun, 11 Apr 2010 16:58:40 BST, Michael Dillon said:

Would a Faraday cage be sufficient to protect against cosmic ray bit-flipping and how could you retrofit a Faraday cage onto a rack or two of gear?

Scientists build neutrino detectors in mines 8,000 feet underground because that much rock provides *partial* shielding against cosmic rays causing spurious detection events. Fortunately, the sun emits almost no cosmic rays. It does however spew a lot of less energetic particles that will cause single-bit upsets in electronic gear. Time to double-check that all your gear has ECC ram - the problem with the UltraSparc CPUs last time was that they had some cache chips built by IBM. IBM said "Use these chips in an ECC config", but Sun didn't. The ions hit, and the resulting bit-flips crashed the machines. Incidentally, Sun sued IBM over that, and the judge basically said "Well, IBM *told* you not to do that up front. Suit dismissed". One of the other big issues will be noise on satellite and microwave links screwing your S/N ratio. The one that scares me? Inducted currents on long runs of copper. You get a 200-300 mile 765Kva transmission line, and a solar flare hits, the Earth's magnetic field gets dented, so the field lines move relative to the stationary copper cable, and suddenly you have several thousand extra amps popping out one end of that cable. Ka-blam. The big danger there is that many substations are not designed for that - so it would basically *permanently* destroy that substation and they'd get to replace it. And of course, that's a several-weeks repair even if it's the only one - and in that sort of case, there will be *dozens* of step-down transformers blown up the same afternoon. How long can you run on diesel? ;)