POE switches and lightning

Marshall Eubanks tme at americafree.tv
Fri May 14 17:52:37 CDT 2010


On May 13, 2010, at 2:26 PM, Mark Mayfield wrote:

> About a month ago, we had a lightning strike near our main campus.   
> We lost one POE Cisco 3560 completely (apparently blown power  
> supply), and in a separate but nearby building, another 3560 lost  
> the ability to deliver POE, but continued to operate as a switch.   
> Both had to be replaced. Both were on wiring closet type UPS'es with  
> surge suppression, and those were unaffected.
>
> Mark
>
> -----Original Message-----
> From: Caleb Tennis [mailto:caleb.tennis at gmail.com]
> Sent: Thursday, May 13, 2010 10:37 AM
> To: North American Network Operators Group
> Subject: POE switches and lightning
>
> We had a lightning strike nearby yesterday that looks to have come  
> inside our facility via a feeder circuit that goes outdoors  
> underground to our facility's gate.
>
> What's interesting is that various POE switches throughout the  
> entire building seemed to be affected in that some of their ports  
> they just shut down/off.  Rebooting these switches brought  
> everything back to life.  It didn't impact anything non-POE, and  
> even then, only impacted some devices.  But it was spread across the  
> whole building, across multiple switches.
>
> I was just curious if anyone had seen anything similar to this  
> before?  Our incoming electrical power has surge suppression, and  
> the power to the switches is all through double conversion UPS, so  
> I'm not quite sure why any of them would have been impacted at all.   
> I'm guessing that the strike had some impact on the electrical  
> ground, but I don't know what we can do to prevent future strikes  
> from causing the same issues.  Thoughts?
>
>

It is not clear to me from the above if there are copper circuits  
coming into the building, but lightning can certainly zap those as  
well. In very high impact areas (such as mountaintops or Miami) it is  
a good idea to mandate that all incoming / outgoing circuits are on  
fiber, without exception.

Marshall

>
> Confidentiality Statement: The documents accompanying this  
> transmission contain confidential information that is legally  
> privileged.  This information is intended only for the use of the  
> individuals or entities listed above.  If you are not the intended  
> recipient, you are hereby notified that any disclosure, copying,  
> distribution, or action taken in reliance on the contents of these  
> documents is strictly prohibited.  If you have received this  
> information in error, please notify the sender immediately and  
> arrange for the return or destruction of these documents.
>
>





More information about the NANOG mailing list