On Aug 19, 2014, at 11:48 AM, Victor Sudakov <[email protected]> wrote:
> Scott Granados wrote: >> This problem sounds a lot like a dissimilar grounding issue. Sounds >> like a potential between buildings is causing problems. I don?t >> know if this is feasible but a common ground might solve some of the >> problems. >> > Our electricians say that everything is correct, that all the > grounding circuits are interconnected and they measure their > parameters annually. I lack the necessary qualification to call them > liars (even if they are lying which I doubt). It still might be interesting next time you have a failure to put a voltmeter between the switch chassis ground and each pin on the ethernet cable that blew the port. If you see anything measurable that might at least tell you if its something like a transient lightning-induced spike or a weird grounding issue (I think). OT, but long ago I worked at an ISP where we once had a few hundred phone lines going to modems and the lines ran up the buildings freight elevator shaft. Each time someone had a freight elevator delivery you could hear the sound of a bunch of modem relays clicking as a bunch of users were disconnected. This was voltage induced in the phone cables from whatever power cable the bundle was lashed to. Charles > -- > Victor Sudakov, VAS4-RIPE, VAS47-RIPN > sip:[email protected] > _______________________________________________ > cisco-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
