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Comment by richardw | Hacker News Reader

I’m looking at using fiber and media converters to connect 7 houses and 2 entrances in a security estate. Main reason is to get IP cameras (and shared access to them) at various points but reduce the impact a lightning strike would have. We have a lot of lightning in this area and I’d be bleak if one strike wiped out multiple houses worth of network and gear.

If anyone has done anything like this, advice welcome.

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1) Never never never never use copper ethernet between buildings. If lightning hits a tree or anything even remotely close to a buried cable you could be easily looking at frying every single device on the entire network in all buildings -- not even kidding. This happened to a popular tech youtuber TWICE before he switched to fiber.

2) If you want to know what went wrong and where use switches with SFP slots instead of media converters. This also makes fixing problem cheaper and gives you flexibility in choosing optics. Even if you do go with media converters, use ones with modules.

3) Build intra-building topology with some form of path redundancy. Since the cost of doing anything like this is so heavily weighted in building the physical links, you may find that you can build a redundant ring topology (only one extra link) at a 10+gbps at a lower cost than a non-redundant hub and spoke topology at 1gbps if the latter requires longer runs. Well maintained UPS's at each node are more important in rings, so think about this too.

Funny. Your first sentence had me wondering whether you're south african. Then you followed up with lighting strikes :-) Agreed, I think your best option is fibre. A few Mikrotik's (reasonably priced) and SFP modules will work perfect for you. I think just getting your own splicing kit will make this easier for you and allow some experimentation.

Don't forget that outdoor cable oftentimes has a metal strength member in it so it can be run from poles. The underground direct-bury kind of cable has metal armour for rodent-proofing and protection when the ground settles. Just because it's fiber cable doesn't mean you can forget about lightning protection and proper grounding. If the airwaves aren't too congested wireless might be a better option here.

You can always blow metal-free fiber in pipes. I'd use PE pressure pipe of suitable size, pull a string into it with a vacuum cleaner and pull fiber in... Hopefully the fiber survives.

Joburg :)

I ran fiber between my house and detached garage (which also includes my office). Installed some large conduit so the preterminated fiber could be pulled through, ran it just like any other cable (trying not to bend it too much), and installed SFP modules in two Unifi switches. I'd never done anything with fiber before, and it was incredibly easy.

I opted to install twelve strands of single-mode fiber. It's insanely overkill (I'm only using two strands right now), but the cost difference was minimal.

With something as complicated as 9 separate locations, I'd definitely avoid unmanaged media converters. Managed ones will be able to tell you how well, or how poorly, your fiber links are doing.

Metallic ethernet is explicitly not designed to be used between separate buildings so you really should not use it for that application. The physical layer can survive surprising overvoltage conditions, but it is insufficient for lightning strikes and there is no sane way to add surge protection at the building entry as would be done for telco outside plant copper wiring.

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