Failing switch - it can happen

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  • Updated 1 year ago
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Just in case you can't think it will happen, it can.

This morning, my VoIP phone showed off line. I did the usual reboot, etc. No joy.

I changed the cables. Still not working.

After about 30 minutes of trying the obvious, I moved on to the not so obvious.

The phone has been connected to the same switch for about 8 years. It has worked flawlessly. And, no matter which port I plugged it into, it would still not get a DHCP address.

The only obvious thing was to change the switch, which I did. Tada, it is back online. That is the only thing I changed.

The moral of the story is that any part of the technology chain can fail. Even if it was working yesterday.

Mike va3mw
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Mike va3mw

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Posted 1 year ago

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Kirk

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I think the big question here is, what caused the switch to fail?  Any idea?
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Mike va3mw

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No RCA on the switch. It wasn't worth my time. It was about 8 years old and time for what I call the 'technology toss'. That usually results in it landing in the big round bin.
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Tim - W4TME, Customer Experience Manager

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I bet some caps blew
(Edited)
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James T. Lee

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This very tactic of "sub-component substitution" has become apparently rather common in -- of all places -- automotive diagnosis and therapy.  Several years ago my brand new 2010 Prius suddenly (and I mean SUDDENLY) gave me the master caution warning light as it lost all front brake function.  This happened at 75 mph in the dark of night on I-94, temperature 20 below zero, in the middle of a Wisconsin winter.

When this car was finally "on the operating table" back in Minnesota the most experienced mechanics were highly frustrated because no fancy diagnostic tests, nor reasoning alone, gave them any initially workable clues and Toyota was on the hook since the car was obviously within warranty.  So ----wait for this----they simply replaced the entire electronic sub-component that controls actuation of the front wheel disc brakes.  And, the deadly problem was solved!  I drove that car another 201,000 miles, with zero problems, and traded it ultimately for a larger vehicle.

Sometimes the arbitrary replacement of the logically smallest influential component is smart, fast, and efficient. It involves trusting by analogy that the shortest distance between two points is indeed and always a straight line. And, the concealed and slick benefit of this gambit is that if it does NOT solve the problem at hand, that negative result is itself often a highly useful and powerful piece of information that informs subsequent decision-making.

NK7B
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Ria - N2RJ, Elmer

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We had a procurve fail last week. Alert popped up and I had the noc guys go investigate. Entire thing was frozen. HP swapped it out. No downtime as we are fully redundant.

Even expensive switches fail but we are pushing terabytes of traffic hourly through those things.
(Edited)
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Ria - N2RJ, Elmer

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When I was lead admin at a large financial we had to replace HBAs pretty often as well, as much as one per week. No idea why other than the fact that we had so many. Meanwhile in Trinidad as a sun field tech I only remember replacing HBAs and GBICs at customer sites a few times and usually in rough industrial environments like ammonia and methanol plants and oil/gas installations. Go figure.
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Jim Gilliam

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I had my Vonage phone fail with the same problem. I solved my problem by powering down both the cable modem and router and sequentially brought them back up. Problem solved.

Jim, K6QE

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Norm - W7CK

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I've had a hard time keeping POE switches operating long term.  Seems every 4 years I'm swapping one out.