Lightning killing cablemodem ethernet port.

GotNoRice

GotNoRice

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A little backstory. The house did not have cable service and is located about a quarter mile away from the road where the cable ISP's lines are. They were not willing to run cable all the way to the house, claiming it would be too expensive. The house uses a well for water, and the little building with the pump in it is much closer to the street. The cable ISP, as a compromise, agreed to run cable to the little well house. The cablemodem in the well house is then connected to the router in the house, almost exactly 100 meters away, via Cat6A. Only the cablemodem and a UPS are located in the well house.

It has worked pretty well for the most part, although it has been picky about wanting to link up at gigabit speeds, which I assume is due to being near max distance (according to gigabit specifications) on the cable.

The most recent issue is that lightning struck the yard and instantly killed the ethernet port on the modem (Arris SB6183). I assume it's more susceptible to this due to the 100 meters of cable in the ground. Thankfully the router on the other end did not seem to be affected.

The UPS I have has two ethernet ports, which I assume are for surge protection, and would seem to be what would be needed for this, however they appear to be passive ports. Unfortunately using the passive ports on the UPS and adding an additional short cable, in addition to the 100 meters on the main cable, is enough to prevent linking up at gigabit speeds as well as cause massive packet loss since the cable seems to already be at it's max length before that.

So I'm sort of brainstorming for ideas at this point. I'm using the opportunity to upgrade the Arris SB6183 to a SB8200 but I don't want to replace a $150 modem every time lightning strikes. I'm thinking of sticking a cheap $20 gigabit switch in there with the modem, as sort of a buffer between the modem and the router. Presumably any surge/lightning strike on the ethernet would take out the cheap switch first, but not sure if it would still continue to the modem or not. Using the cheap switch might allow use of the passive port on the UPS also since, being on another port of the switch, it would no longer basically just be adding extra length onto the 100 meters of the primary cable. Not sure how that would work in practice though, and would love any other ideas.
 
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If you can run a cat5e cable from the shed to your house, why not jut extend the coax cable that distance and move all equipment to the house?
 
Biznatch said:
If you can run a cat5e cable from the shed to your house, why not jut extend the coax cable that distance and move all equipment to the house?
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Interesting question. It's been a couple years since it was first installed. I recall asking the ISP that very question back then but I can't remember exactly what their reason was for claiming it probably wouldn't work. I think the cablemodem is already pretty far from the CMTS.
 
300 meters of Cat 6e is about 3x the recommended distance. Depending on the cost, might consider running fiber from the well house to the residence. Is the current cable directly buried or in conduit?

Was the Cat 6 properly grounded on both ends?

Lighting can be weird. I get DSL via buried copper phone line in a rural location. Had a near hit, felt the thump more then heard it. Didn't hurt the DSL but blew out the ring circuit in an upstream box. I could call out but would not get incoming rings but did get a ring tone. It also blew the protector on the power pole.
 
Dead Parrot said:
300 meters of Cat 6e is about 3x the recommended distance.
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Yeah thanks for pointing that out, I had my numbers mixed up a bit. It's actually about 100 meters.

Dead Parrot said:
Is the current cable directly buried or in conduit?
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The cable is supposedly rated for waterproof/underground/direct burial, and it's also run through flexible plastic tubing.

Dead Parrot said:
Was the Cat 6 properly grounded on both ends?
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No, just plugged directly into the cablemodem on one end and into the router on the other end.
 
Definitely sounds like fiber/media-converter time, just upgrade your flexible tubing to something a bit more robust :)
 
If the flex tube/conduit is large enough, you might be able to get a fish tape though to allow you to pull a fiber set. Pay once for the fiber/media converters and fix the problem.

If the conduit isn't large enough for both, you should be able to use the existing cat 6 as the pull cable and pull it out as it pulls the fiber through. Does have the risk of if something goes wrong, you have no working cables.

In either case, recommend using direct burial rated fiber if it will fit in the conduit. Extra protection against settling rocks or roots rarely hurts.
 
You can get direct burial fiber and run from the shed to the house, use media converters on both ends, won't have to worry about ground differentials and lightning and all that jazz with a fiber cable.

Or you can put in conduit and fish cable through. I'd just do direct burial if it were me.

First link in google, armored direct burial single mode for $0.50 a foot.
https://www.discount-low-voltage.co...r/6-strand-Singlemode-Armored-006EUC-T4101D20
 
Like others said, fiber is the way to go. I worked for a government entity at one point and we had three buildings on a campus, and they were constantly getting hit by lightning. Initially we added a network line surge suppressor to the buildings. So the cable was
[switch] ------ [surge suppressor] ---------[other building surge suppressor]---------[switch]

That worked for a short while. We tried aerial cable, and buried conduit cables and both had issues. Later we changed everything out for fiber and didn't have an issue anymore.
 
Haven said:
Like others said, fiber is the way to go. I worked for a government entity at one point and we had three buildings on a campus, and they were constantly getting hit by lightning. Initially we added a network line surge suppressor to the buildings. So the cable was
[switch] ------ [surge suppressor] ---------[other building surge suppressor]---------[switch]

That worked for a short while. We tried aerial cable, and buried conduit cables and both had issues. Later we changed everything out for fiber and didn't have an issue anymore.
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Just curious what other issues you were still having? Was stuff still getting taken out by the lightning or are you talking about packet-loss, not linking-up at max-speed, or something else?

The fiber idea definitely makes sense. I'd probably go that route if I was setting it all up for the first time today, and will for sure keep that on the menu for if/when I replace the cable next time. It was *such* an epic pain in the butt laying the cable the first time though (it's not just 100 meters away, it's 100 meters up a hill) that I'd almost rather press my luck with the new modem on the existing cable. Plus the fact that the previous SB6183 lasted over 2 years before the mother of all lightning bolts finally got it. If it had only lasted a month that would be different. For now I went ahead and put a cheap sacrificial gigabit switch in there with the modem so that any surge on the cable will have to pass through that before it gets to the modem. Not sure how much it will help in practice but I don't think it can hurt. Thanks everyone, I do appreciate the advice.
 
I'm very surprised a lightning strike did not take the cable as well. The last time we had a strike the incoming phone lines burned and every device connected was fried including the jumped ground block. That was a direct strike though that actually cracked a couple of windows as well. Sounds like what you had could have easily been a non issue if the cable had been properly grounded. You really need to ground that cable. Not doing so could very well end up killing you or your family when it burns your house down when the next strike comes. That said, as has already been said above, fiber is really the way runs like that should be done.
 
Sounds like you may have a grounding potential difference between the pump house and the main house. What is the coax ground block actually grounded to? At that distance having a ground potential difference isn’t uncommon and makes lightning damage more likely.

Personally I would get a single port drop amp with an active return and place it in the pump house and run coax to the main house. Unground the cable at the pump house and ground the cable to the main house ground at the house.

The loss over 100M of rg6 at 1ghz would be about 18db. I usually use the PCT PCT-MA-B1015-1A which has a 14db gain. If you log into the cable modem and look at the signal levels you will be able to determine if you can afford the extra 4db loss. If you can’t afford the 4db loss you will have to use RG11.

You could actually run 2 amps if you needed to, especially if you have a halfway point near a utility pole or fence post you could mount the amp on. You would power the amp in the pump house with a power inserter in the pump house. The second amp would be powered by a power inserter in the house so no power is necessary where the 2nd amp is mounted.
 
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GotNoRice said:
Just curious what other issues you were still having? Was stuff still getting taken out by the lightning or are you talking about packet-loss, not linking-up at max-speed, or something else?

The fiber idea definitely makes sense. I'd probably go that route if I was setting it all up for the first time today, and will for sure keep that on the menu for if/when I replace the cable next time. It was *such* an epic pain in the butt laying the cable the first time though (it's not just 100 meters away, it's 100 meters up a hill) that I'd almost rather press my luck with the new modem on the existing cable. Plus the fact that the previous SB6183 lasted over 2 years before the mother of all lightning bolts finally got it. If it had only lasted a month that would be different. For now I went ahead and put a cheap sacrificial gigabit switch in there with the modem so that any surge on the cable will have to pass through that before it gets to the modem. Not sure how much it will help in practice but I don't think it can hurt. Thanks everyone, I do appreciate the advice.
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The original cable was aerial cable, it got hit by lightning and was in two pieces when I got there, and two switches were toasted. Then we did conduit, we still had an issue where we toasted a pair of switches after a lightning strike. We replaced the surge suppressors after that. Then it got hit a few more times and eventually I had to replace two switches again.

There were three buildings on that campus, in a small area (half acre maybe). Building 1 was connected to Building 2, which was connected to Building 3. When we did switched to fiber we ran it from Building 1 to building 2 and 3, and fiber from building 2 to building 2. We did it as a mini fiber ring.
 
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