Can’t fish Ethernet? Use “invisible” fiber instead

https://momandpop.network/2026/11/02/cant-fish-ethernet-use-invisible-fiber-instead/

30•_mpn_•1h ago

Comments

elevation•1h ago

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).

no_carrier•47m ago

Network engineer of 20+ years here, but I'm struggling with this 'fished' terminology. Does it mean when a cable is pulled through on a piece of string?

phyzome•40m ago

Yep! Might be a more common term among electricians.

topspin•26m ago

> Does it mean when a cable is pulled through on a piece of string?

That is often exactly what is meant. The problem of running Ethernet through existing structures has spawned a bunch of tools, including glow-in-the-dark "fish tape."

The process is often brutal, and looks like tug-of-war when it takes a couple men to pull the bundle through a couple 90 degree turns. As such, we have "plenum" cable, which is much tougher than typical patch cable, because the latter would just get shredded inside the structure, or snap when pulled with a few hundred lbs of force.

tylergetsay•12m ago

For really long runs in industrial settings they have battery powered pullers that use a really strong string.

mmastrac•44m ago

It's definitely pair damage, but could also be a drill or other nick (ie: making potlight holes), or even stapled wire.

Recrimping is always the best first step. Sometimes running 2.5gb instead of gigabit will help too.

_mpn_•26m ago

I tried recrimping the connectors. It did nothing.

jrm4•56m ago

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?

dale_glass•47m ago

Fiber is much nicer. You can get as much bandwidth as you'd ever want.

10G is trivially doable on cheap hardware. You can also go 100G, 200G or 400G over the exact same cable, it just costs a lot more on the endpoints.

If you run anything modern you probably can benefit from 10G at least. A NVME does 8 GB/s easily, it's a real pity to limit speeds to 1 gigabit. And Ethernet past 1 Gbps quickly gets pretty terrible to deal with, so might as well go with fiber then.

toast0•26m ago

10G on twisted pair isn't too bad either. Used enterprise NICs are cheap on eBay. New low cost cards are available, too (still costs more than used gear, but if you want lower power or multigig, it's worth a look). Switches aren't so cheap, but IMHO, 10g-baseT is comparable to sfp+ and a transceiver on each end.

Obviously, if something is wrong with your existing cabling, 10g-base-t is probably not going to work either. 10G is probably the limit for twisted pair, but I think it'll hold up as a reasonable speed for a long time.

dale_glass•16m ago

10G on twisted pair is terrible, it's power hungry and the SFP modules have a tendency to overheat. You need decent ventilation and not have 10G twisted pair connectors next to each other. Also only goes to 30M or so.

IMO, if you want 10G just go with fiber, it's less of a pain and more reliable. With twisted pair you may find out that the module overheats at times and the link drops out.

favorited•55m ago

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 close. You're far more likely to notice the spots where someone got sloppy with the glue in some corner than the fiber itself. With proper attention to detail during installation (and assuming you have white door jambs and baseboards) it would be basically invisible.

_mpn_•25m ago

This also happened in my previous place with Verizon Fios (pre-war co-op rental), but only in the hallways. In the unit Verizon ran thicker fiber.

dale_glass•50m ago

You can fish standard fiber very well too. It's thinner than pretty much all network cable.

The biggest part is the LC connector, and you can just take that apart and put it back together -- just remember which was the left and which was the right wire.

That should save the need for special hardware.

readthenotes1•46m ago

I guess there is no point in taking a picture of invisible fiber

dale_glass•43m ago

You can see it:

https://momandpop.network/wp-content/uploads/2026/11/PXL_202...

Zoom in on the black box. There's an orange ethernet cable plugged in, and the other plug is the "invisible" fiber.

xbar•30m ago

This was helpful. I found the invisible fiber hard to see.

zamalek•44m ago

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?).

_mpn_•24m ago

I do not have Coax running in the house. If I did I would've used it.

But our townhouse was renovated in a post-cable era so Coax was never put in. If it was a 1-2 decades older it would've had coax.

rbanffy•40m ago

Last time I cabled my house I laid out two cables between the switch and every spot, precisely for this reason. I think now I’d lay fiber as well, for future use.

bluGill•29m ago

I've seen technology change far too much to do anything for future use. I remember running RG58 coax between rooms for ethernet. Then cat 3 for 10baseT. I came close to running fiber at one point but it would have been the wrong size fiber for anything modern (62uM still works but is out, and it would have been terminated wrong. If you want a future proof, you run yourself conduit from each room to a central data closet and put a string in there so you can pull whatever cable you want when you want it.

mscdex•23m ago

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 tight bend radii without breaking (exceeding G.657.B3). Also, pairing it with bidirectional transceivers means you only need to run one cable to each endpoint.

_mpn_•12m ago

Mine is 0.9mm thin, but still excellent. In fact I got mine tangled and yet it works great.

Quite frankly, people should be doing fiber LANs more, even if the WAN is coax or wireless.

sonicvroooom•16m ago

German here, living in single digit distance to military areas.... The shit they buried under argon et al decades ago, man ... tap in if you have the patience ... gives you seconds around the globe

wyager•12m ago

These days you can get a cheap-o chinese fiber splicer kit for like $500-800. They work pretty well and are in many ways simpler than terminating ethernet. Super convenient for wall pulls and so on.

pak9rabid•12m ago

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?