[geeks] Whee! Lightning strikes, AGAIN!

[Lionel Peterson]

On Jul 30, 2009, at 12:51 PM, Barry Keeney <barryk at chaoscon.com> wrote:

> On Wed, 29 Jul 2009, Lionel Peterson wrote:
>
>> On Jul 29, 2009, at 12:20 PM, Barry Keeney <barryk at chaoscon.com>  
>> wrote:
>>
>>> On Wed, 29 Jul 2009, Lionel Peterson wrote:
>>>> The dead switches, router, and cable modem all power on, but have
>>>> dead
>>>> NIC ports, again, discounting the idea a power surge came in the
>>>> power
>>>> line in my mind.
>>>
>>> Well it's still possible that the surge entered from the power grid
>>> and moved to the network devices via a poorly designed device(s)
>>> (switch,
>>> router, etc) that allowed the surge passed it's power supply to the
>>> network cables.
>>
>> Wouldn't a lethal surge take out the system that took the hit?
>
>  Depends, sounds like the NIC's jump in front of the bullit giving  
> thier
> up lives and not passing the charge into the rest of the computer.

That's my assumption.

>> All I
>> lost were NIC ports, the WAN and ETH1 ports on my router, the LAN  
>> port
>> on the cable modem, and *only* the switch ports that had wires  
>> died...
>
>  I can't say for sure that any of this is going to be your problem,
> but could give you some ideas on what else to check...
>
>  It sounds like, from what I remember, you have a larger switch,
> something around 24 ports? They normally have several chips  
> controlling
> the ports, smaller 4-8 port switchs can have as little as one ethernet
> chip. More chips, the more that have to be damaged to cause all the
> dead ports.

My 'dead' network had two 24 port netgear switches, one off the  
router, one in the second floor office. Both have lost between 6-10  
ports (either fried or at least questionable) to me, not worth fixing,  
since I have a Cisco 2950 in the basement, and I'll put a gigabit  
switch in the office. The 2950 is 24x Fast Ethernet, and two Gigabit  
ports (RJ45), that should suffice for now.

>  I would guess that the surge didn't come from the switch and only
> passed thru it using a common path shared by the used ports. Without
> looking inside I would think it was a ground path(s). All the signal
> leads would pass strait into the chip and it would be harder for the
> surge to keep moving to ports on other chips.
>
>  It could be something between the jack and the controller chip(s)
> inside the switch (cap, diode, etc) then it's likely the surge came
> in from the network and passed to other used ports using something
> shared, like a ground. No cable in a port means that the network cable
> was some how required and without it the surge didn't have a path to
> whatever device that died on the cabled ports or into the chip or part
> of the chip controlling that port. Possible damage to the ethernet  
> chips,
> but still working.
>
>  If the surge cable from just the power supply on the switch it would
> likely fry something that would have killed the whole switch or fried
> all the ports controlled by whatever chip(s) have cabled ports  
> attached.
> The surge passed thru controller chip(s) to the network cables, should
> have kill the whole chip.

I'm too disgusted to investigate, but your analysis seems right.

>  If all the systems still work, just bad NIC's, the surge didn't come
> from any of them. Whatever killed the NIC's would likely kill  
> something on
> the system as well, memory, CPU, disk controllers, CD/DVD/hard drives,
> something before passing into the network.

Yep, dead NICs, everything else is fine...

>  If the router still has working network ports (like the switch), it's
> most likely the cable modem that passed the surge in. If you plan on
> using ethernet cable surge protection and want to keep it cheap, I'd  
> put
> one between the cable modem and the router. If you're not sure if it's
> the modem or router, use two. One between the modem and the router,  
> and
> one between the router and the switch.

Linksys WRT54L, lost WAN and first Ethernet port - it's about to  
become an AP, unless my insurance company wants it.

>  Also a good idea to double check the electrical outlets, they could  
> have
> grounding problems as well. It's also possible that there is something
> in the house wiring done wrong or badly. If you can have someone  
> take a
> general look it couldn't hurt. I've got a friend who's an electrican  
> so
> something like this cost a 6-pack

Good idea, thanks.

>  I also check the ethernet cables (kind of hard if they're in walls)  
> for
> damage. Small cridders sometimes like to chew on them or they were
> damaged as they were pull thru and there might be a short(s)

I've got a cable tester, that gets me part-way there...

>  Nope this helps...

It does, thanks.

Lionel