Re: Good UPS for network equip?

From: w_tom (w_tom1_at_hotmail.com)
Date: 07/23/04 

Date: Fri, 23 Jul 2004 06:58:01 -0400

  You see no evidence that a cable has lockup up the router
because you have not yet run those comprehensive
diagnostics. You are not doing what your car mechanic must
do to not be sued. You are not doing what your doctor does
before perscribing medicine. You are speculating this must be
a power problem only becasue the routers master reset cleared
the problem. First thing you should have done is run those
diagnostics. Make the intermittent into a solidly repeateable
problem.

  Again, do you know the cables are wired correctly
internally? Did you run comprehensive diagnostics to see the
problem, then swap out with a know good cable, run the
diagnostic again, and see no failure? From the symptoms as
described, a long list of reasons could create the problem.
One of those reasons is most likely in a low bandwidth
environment. One of many reasons for lockup would be a cable
not properly assembled. Network would work sometimes; then
eventually lock up. Lockup is then cleared by the router
master reset that only occurs with power removal. And this is
only one of many possible reasons for the failure.

  With this one type of failure, you could ping all you want
and that still would not create the failure. Again, I
probably have a generation plus experience on you with this
stuff. Experience based upon design - not just simplistic
part swapping. Having been there, the quickest and most
reliable solution to this problem was provide previously -
including the loope. Having experience, the only reason a
power glitch can cause your problem is if that entire line of
routers is defective by design. Defect in all routers of that
design which means that router works in 99 locations and
becomes intermittent in one. Your symptoms are also of
problems that have nothing to do with power. If you had a
problem created by power, then the entire line of routers is
defective - and you used a better design.

  You did verify power by running an extension cord between
outlets so that a meter can confirm wiring? If power was a
problem, then the meter is the first thing you used to confirm
building wiring (and no, those little cubes with three lights
would not detect the type of failure you were looking for).

  Diagnostics are so simple to obtain and execute that it
takes longer to make a second trip to that office.
Diagnostics were created to solve just this type of problem.

 In the meantime, what did the lights on the router for each
cable and on each NIC report both during operation and during
the outage. Once problem happens, then which computers can
ping or not ping which other computer (which is why you left a
batch file script on the desktop of each machine so that the
user can execute that test and report back).

  Possible reasons for your failure: miswired cable.
Impropely connected RG-45 plug to cable. Serious safety
ground problem with the office wiring. Defective
(intermittent) NIC in any one computer.

  Restarting electronics will always cure the intermittent.
Clearing failure is the job of the master reset circuit that
all computer electronics must have. A defective state machine
is always reset by the master reset; therefore the
intermittent is always cleared. That does not say anything
about power. It only says the master reset circuit works.

DaveC wrote:
> Environment: small 4-person medical office. These are not huge
> bandwidth-using people.
>
> Equipment: 1 PC, 3 Macs connected via 10-baseT to Netgear RP614v2
> router. Router firmware is current release.
>
> Symptoms:
> 1. Every 2 weeks, or so, suddenly no one connected to the router
> can access the 'net. No one was attempting to use the internet
> at the time of the failure, they just found that their computer
> couldn't print to the network printer. I can ping the "immediate"
> router (that their computer is plugged into), but not the one
> beyond (that the printer and DSL router are plugged into).
>
> Replaced the router, as it seemed defective.
>
> Then, on one weekend, an office worker was present when the "lights
> flickered", and network symptom occurred. I started thinking about
> power problems, and office workers confirmed that the lights would
> flicker several times a week.
>
> Restarting the router fixes the symptom, every time it occurs.

Relevant Pages

  • Re: Good UPS for network equip?
    ... You see no evidence that a cable has lockup up the router ... diagnostics. ... do you know the cables are wired correctly ... master reset that only occurs with power removal. ...
    (sci.electronics.misc)
  • Re: Good UPS for network equip?
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  • Re: Good UPS for network equip?
    ... You see no evidence that a cable has lockup up the router ... diagnostics. ... do you know the cables are wired correctly ... master reset that only occurs with power removal. ...
    (sci.electronics.basics)
  • Re: Good UPS for network equip?
    ... How do you activate a computer's master reset after computer ... Either press the master reset button, or power ... is problem in the router or is it something ... Run those manufacturer diagnostics and use alternative ...
    (sci.electronics.misc)
  • Re: Good UPS for network equip?
    ... How do you activate a computer's master reset after computer ... Either press the master reset button, or power ... is problem in the router or is it something ... Run those manufacturer diagnostics and use alternative ...
    (sci.electronics.repair)
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