Today, over $6,000 in networking equipment was destroyed. Remarkably, the main circuit SPD, power strips and APCs are fine. Ethernet seems to be the method of surge transmission, as everything connected to the physical network up until the fiber links was fried. What makes this event unique (for me) is the flash, bolt of lightning, ball fire and loud bang that was observed.

I’m surprised by this damage. First, because the room is protected by grounded perimeter (and centerline) copper wire with frequent aerials. Second, we have a good ground network. And third, the bolt observed was at least 1 meter away from the plastic conduit that carried the network cables.

We’re in an area with extreme lightning activity and up until now, I thought we had done a good job of protecting the network.

So, what more can be done? Should our Ethernet cables be put into large grounded metal conduit? Or, a grounded cage above the plastic conduit?

The ceiling space the Ethernet conduit is run in has metal studs and a roof above. Should we go so far as installing direct grounding from the stud network? Or, would that simply make things worse by “drawing” future strikes into the studs increasing EMF damage risk?

  • I'm sorry, you were close enough to witness the flash, bolt of lightning, ball of fire and loud bang? You witnessed a direct lightning strike a mere 1 meter (3 feet) away?
    – joeqwerty
    Jan 3, 2018 at 19:49
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    Such damage is hard to protect. I seen a site, where all cisco switch died from a surge that hit a ethernet line. Over 40k of damage. Fiber uplink between switch help
    – yagmoth555
    Jan 4, 2018 at 0:23
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    @joeqwerty: No, the observation distance was about 4 meters. The 1 meter minimum distance was from discharge point to Ethernet cable conduit.
    – Justin
    Jan 4, 2018 at 2:33
  • @yagmoth555: Terrible to hear. I’m really hoping there is more I can do. Replacing equipment like this is painful. I’m going as far as to decentralizing our network by switching to a wireless mesh on more significant portions and accepting the performance loss.
    – Justin
    Jan 4, 2018 at 2:35
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    Related serverfault.com/questions/408130/…
    – Moshe Katz
    Jan 4, 2018 at 17:52