Fiber Optic Internet

I should point out that there is also a potential surge path using F-E-F conversion, and that is through the power strip.

Imagine a surge enters your first F-E converter, that then travels to the power strip... :-)

So, nothing is perfect, and this scenario still requires a pretty large strike to bridge the Ethernet AND the power supply to damage elsewhere, but just saying...

OP:

You can’t really get surges over fiber. What can happen though is that they will run fiber to a box OUTSIDE your house, and then transition to Ethernet from outside to inside, and that’s a potential surge source through EM coupling. That coupling is worse the longer the Ethernet cable is. If you have a 5’ run that’s probably OK, but if it’s 20’ or longer it may be worth having an Ethernet isolator.

From what I have read, but now can’t find, the latest thinking on surge protection for Ethernet is to isolate, not ground, surges. The research on Ethernet protection I read is saying that if you ground a surge inside a building (via a MOVs or gas discharge tubes) you actually cause more damage by creating an easy path for high current, and when that lightning flows things melt, including wires and gear on the other end of the "protection." Some research even points to systems that might otherwise survive instead  fail specifically because of Ethernet surge protectors creating a ground path. Because of this, inside a building you want to avoid any Ethernet surge protection which provides a ground path on surge.  Do your grounding outside.

To reduce the chance of lightning induced surges over Ethernet you want one of these instead:

or the significantly more expensive version from Trip Lite:

I have about 60-80' between my router and my entertainment system.  Plenty long to get an induced lightning surge with a little bad luck so I am using the cheap one there.

PS - Avoid Ethernet surge protectors that have ground wires.  They dont' work as well as the isolators.

Hey,

So on that end, protection from surges is a big deal, so pay attention to what actually bridges the outside of your home to the inside. If it’s any form of copper, get an Ethernet isolator (about $40 or less) at the very least. The Ether-Fiber-Ether bridge is also a good idea and one that I use but not for improving audio. :-) I’m just paranoid about surges taking out a significant chunk of my home network.

I have a coax based Internet and so I use a gas discharge tube on the outside, that goes to the modem, and then a custom made E-F-E bridge. It’s basically an air-gapped lightning protection.