DIY 'invisible' fiber retrofit solves degraded Ethernet in NYC townhouse
A homeowner replaces a failed Cat6 cable with thin apartment-grade fiber optics to avoid wall damage and contractor costs.
What to know
- Thin fiber optic cables originally designed for apartment retrofits offer an alternative to ripping walls when Ethernet cables fail or new runs are needed.
- The cables are inexpensive, available on Amazon and AliExpress, and can achieve 10 Gigabit speeds while remaining nearly invisible when installed along baseboards and door jambs.
- Commenters debated whether the original Ethernet degradation likely stemmed from connector termination issues rather than cable failure, suggesting diagnosis before replacement.
- Multiple users confirmed the technique works at scale—one reported a 300-unit apartment complex using identical fiber retrofits from AT&T.
The dispute Whether fiber retrofit should be the first choice versus troubleshooting existing Ethernet termination or deploying simpler alternatives like MoCA. · positions read across 10 posts and comments
Fiber retrofit is a practical, proven solution that works at scale and is widely available for retrofits.
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“This is how my apartment complex retrofitted all 300ish units with AT&T fiber.”
favorited · Hacker News ↗
The original Ethernet problem is likely connector termination, not cable failure, and should be diagnosed before replacing infrastructure.
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“If your CAT6 is down to 100 Mbps, check that all the conductors have been properly crimped into the connector -- or consider re-crimping.”
elevation · Hacker News ↗
Alternative technologies like MoCA and powerline adapters are simpler and non-destructive options worth considering first.
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“GoCoax/MoCA is a fantastic non-destructive option if your copper can handle it.”
zamalek · Hacker News ↗
_mpn_ NYC townhouse owner and blogger
How it unfolded 3 developments, newest first · click a bar or a number to jump articlespostscomments
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Technicians recommend fiber diagnostics and highlight cable thickness advantages
Commenters with networking experience noted that fiber cables as thin as 0.6mm (fishing-line thickness) can achieve 10 Gigabit speeds and support tight bend radii, while others suggested the original Ethernet issue likely stems from connector termination problems rather than cable failure.
“The best part is that you can get such cabling down to 0.6mm thin (akin to fishing line) and get it pre-terminated, meaning you don't have to drill holes anywhere as it can easily fit through doorways and supports very tight bend radii without breaking.”
— mscdex -
Related: https://michael.stapelberg.ch/posts/2020-08-09-fiber-link-ho...As to the author's core complaint (CAT5/6 degrading to 100mbps), I've found that the issue is almost always the termination at the jacks. Reseating the wires with a punchdown tool, or failing that, cutting a bit more off the ends and ensuring that the pair twists run all the…
2 more of the top 3 · 6 posts in this stretch
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I recently switched to "invisible" fiber after having used various generations of MoCA/G.hn/Powerline ethernet over the years. The best part is that you can get such cabling down to 0.6mm thin (akin to fishing line) and get it pre-terminated, meaning you don't have to drill holes anywhere as it can easily fit through doorways and supports very…
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This also comes in translucent type - basically looks like fishing line so very close to actually invisible. When it's against a wall you can't see it unless you've got a flashlight and are centimeters away.And it'll carry 10gig just fine.Good stuff even though it's a bit of a pain to route it along a path that makes sense, has the right bend…
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Commenters share experiences with apartment fiber retrofits and alternative solutions
Hacker News discussion revealed multiple users with firsthand experience installing similar fiber systems. One commenter described a 300-unit apartment complex retrofit by AT&T using the same approach, while others offered troubleshooting tips for Ethernet degradation and discussed alternative technologies like MoCA, powerline, and G.hn.
“This is how my apartment complex retrofitted all 300ish units with AT&T fiber. Fiber runs from your building's telecom room to a small hole they drilled above everyone's front door, then along baseboards and around door jambs until it reaches ~the center of the unit.”
— favorited, Hacker News commenter · source -
This is how my apartment complex retrofitted all 300ish units with AT&T fiber. Fiber runs from your building's telecom room to a small hole they drilled above everyone's front door, then along baseboards and around door jambs until it reaches ~the center of the unit (concrete walls...) in the living room.It is genuinely invisible until you get up…
2 more of the top 3 · 4 posts in this stretch
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If your CAT6 is down to 100 Mbps, check that all the conductors have been properly crimped into the connector -- or consider re-crimping. It's possible the building has shifted and damaged the fished cable, but it's more likely the problem is with the connector(s).
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GoCoax/MoCA is a fantastic non-destructive option if your copper can handle it. Just make sure you install a filter at your ingress point to prevent sending data to neighbors (MoCA does have encryption, but why trust math when you can trust physics and math?).
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NYC homeowner documents DIY fiber retrofit for degraded Ethernet
A townhouse owner published a detailed account of replacing a failed Cat6 cable with thin apartment-grade fiber optics, achieving ~300 Mbps while avoiding wall damage and contractor costs. The author used a MikroTik CRS304-4XG-IN switch and SFP+ transceivers with SC connectors, choosing removable adhesive over superglue for future flexibility.
“So yes, even if you don't have fiber to the home, fiber is still useful in a home network. As it saved me from having to hire a contractor and possibly tear our walls.”
— _mpn_ (author)
What people are saying 4 voices from 1 site · best of 10 · verbatim
- What is the actual local link speed between endpoints using iperf3, rather than ISP speed test results?
- How does the total cost of a fiber retrofit (including transceivers and switch upgrades) compare to alternatives like MoCA or re-terminating existing Ethernet?
- Nov 3
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Exactly this. And if not this, it’s the transceiver. And when you crimp, pay attention to the tricky color pair routing so common mode noise is rejected properly.
- Nov 2
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Apalrd had a video on this a few months ago, "Hidden ETHERNET at home using FIBER":*
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I'd be curious to see what the actual link speed is between the two endpoints, rather than a speed test out to the ISP. Are you able to do a speed test with something like iperf3 locally?
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I confess, I've read this twice and I don't really get what's going on here; and I have both MoCA and Powerline going on in my house as well, so I'm like -- why not one of those?