There’s NO WAY this works - Debunking bogus network splitters.

Ethernet splitters are all over the internet, but aren’t they just a scam to steal from the uninformed? Well, mostly. But with a little knowledge of the history of networking, you really CAN run two devices over a single network cable!

Purchases made through some store links may provide some compensation to Linus Media Group.

FOLLOW US
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MUSIC CREDIT
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Intro: Laszlo - Supernova

Outro: Approaching Nirvana - Sugar High

CHAPTERS
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0:00 Intro
1:15 Andy's Car Collection
1:14 Let's try them out!
2:16 The Headphone Splitter
4:06 What's going on here?
5:40 Networking like it's 1999
6:51 But Linus...
8:55 Outro

[LinusTechTips]

Since reading comments from you beautiful people, we want clarify a couple things. First, the fact that ethernet is digital (as opposed to analog) is not the reason that these splitters don't work. In fact, some digital signals can be split, such as I2C, DTV, or ARINC.

Second, many other commenters are suggesting using these splitters as passive hubs, but while in the past that could have been a possibility, these splitters aren't wired correctly for that . The transmission pins on the sending device need to connect to the receiving pins on the other end. Simply wiring pin 1 to pin 1, 2 to 2, etc. as we see here does not work.

While some of those old/deprecated features of the earlier ethernet standards could have enabled devices similar to these to work with very old network adapters, few, if any modern network adapters support these features and, ultimately, the wiring diagrams presented on the product page for these don't suggest that the seller intends customers to use them in that way.

Our apologies for not making all this obvious in the video! Now here's some link to real solutions:



Purchases made through some store links may provide some compensation to Linus Media Group.

[joshuatatro]

It's honestly impressive these companies realized less technically inclined people would search for "ethernet splitter" instead of an actual switch, then made a product that looked exactly like what said people were expecting, albeit somehow worse and more expensive than a 2-port ethernet switch. If only they had used their powers for good...

[anekroth]

Hi Linus, random network engineer speaking. That splitter might work if you change all of your network interfaces to half duplex. Half duplex would need to be set on both of the computers connected to the splitter as well as the switch port the splitter plugs into. Half duplex uses a protocol called Cable Sense Multiple Access with Collision Detection (or CSMA/CD for short). Its a protocol that harkens back to the days of yore when network devices communicated over a single wire (like token rings and hubs). On a Windows PC you should be able to change the duplex settings from the network device properties in device manager. As for the switch, you will need a managed switch that allows you to change the port settings.

[chrisspellman]

I made this back in college. Had 2 machines and I was lazy and didn't want to run multiple cables and we didn't have access to a bunch of consumer grade switches. There was already a jack at my station so I made my own 'splitter' with 6 Rj45 connectors (3 at each end). My networking instructor was both disappointed and impressed when he saw it. He knew I knew it was wrong. But also, he appreciated the ingenuity of it.

[wfkvr]

I used to make my own splitters in the military when running another cable wasn't possible or feasible. Was back in the Cat5e days, so we only had 100Mbps switch ports at the edge anyway.

Thanks for bringing back some good memories! 😂

[jajssblue]

Time to daisy chain splitters into a Christmas tree of sadness.

[yiddea]

I did this once a couple decades ago. The building facility manager would not cooperate between our two suites, so I used the telephone panel to split each pair to their own phone jack in the closet and connected the switches via a custom cable feeding all 4 pairs back into an ethernet keystone on each end. Performance was good enough to allow us to complete the move from one suite to the other over a week instead of having to do it overnight. Once done, I removed my handiwork from the closet and kept the two dongles as a trophy for my ingenuity. :)

[AntneeUK]

Surprisingly, this video has helped me diagnose a network issue at home today. I noticed that a wired connection between 2 rooms is running at 100Mbps, which led me to think that one internal wire is broken/disconnected. I never realised that we can run 100Mbps with less than all cables before I watched this. Sure enough, pin 4 is coming back disconnected. All the other wires are good. Not the point of the video, but it helped me diagnose the issue 👍

[Aguyinachair]

Working at Radioshack I heard this a thousand times. We had an adapter that was exactly like the adapter featured in the video. They would refuse to buy the slightly more expensive ethernet switch regardless of how much I protested. Some of them came back and usually apologized; others I'm sure went to other stores to avoid seeing my face again lmao

[cazeyexe]

That physical diagram between the garage and living room was perfect and made everything extremely easy to understand. I'd love to see more like that in the future.

[proudbgeeky]

We used to split CAT-5 cable into two cable connections when I was in the Air Force all the time. My unit's mission was to setup deployable PC/telephone equipment in the field and the less cable we had to run the better. We would even drop a ethernet link to a PC and then use the extra wire pairs for telephones.

[Killerpixel]

As someone still occasionally having to deal with the "proper" splitters, I can tell you they've been around for ages. And they're an absolute nightmare. Because the venn diagramm of people who use these, and people who don't document jack shit in their network, is perfectly aligned.

Oh and also, finding replacement ones for situations where the customer absolutely does not want a better solution (because why would you?) has become a giant hassle, because everything is saturated with the "fake ones" as dropshipped e-waste. Thanks for the sponsor by the way, that particular industry absolutely needs to become

[RnAlsation]

This video's sponsor looks like it helps to build many of the experiences I hate about trying to shop online.

[cristi]

Those devices are actually a gold mine for DIY electronics projects (non-ethernet). I recently used a lot of them to split multiple signal wires very cheaply. Ethernet cables are so cheap and they provide 8 wires inside that can be used for anything.. and those devices provide a very nice solution to duplicating the signal

[Mymatevince]

Fun video. What you built here was a Data / Data RJ45 Economiser, you can also buy them in Data / Voice and Voice / Voice. They often have different colour strain relief boots to indicate by glance what they are. Basically on the Voice versions they are wired up using the middle 2 pins (Pin 4 and 5 blue pair) and the brown pair (Pin 7 and 8). They have been around for many years, but not many know about them 👍 The Data / Voice version is sometimes useful for pushing good old fashioned dial tone down the 1 Ethernet cable with 100Mbps internet as well.

[xlipeyt]

Did Linus really advertise for a Dropshipping buisness?

[alanbarber]

I'm glad you're doing more content like this... Useful to send to my less technically smart family when they ask about junk like this.

[brunoschwizer]

These are used sometimes in Industrial applications where there are simple analog signals (24v power or maybe a digital IO or a 0-10V analog Signal) running over an RJ-45 connector. Then there are some use cases where these are practical. Like let's say you have an analog pressure signal that needs to be read by 2 different sources simultaneously.

[seandaugherty]

Actual Ethernet “splitters” do exactly what you did, and split 4 along each line. And I have seen applications where it was the most practical solution, where we had a buried line under asphalt and needed to have two physically separated connections.

[Jernaumg]

These used to be very common (the correctly wired ones). A lot of older offices were wired up with far less structured cabling than we would do now. Worse yet some of it was probably CW1308 for phones. As more and more devices needed connecting up this became an issue, particularly when IP (and later VOIP) phones became more common. One solution was to use a pair of splitters like this to double up your infrastructure. Yes it was janky but it was also MUCH cheaper than re-wiring a building and didn't disrupt the people working there.
Similar looking devices were also common on digital PBXs which used cat5 cables terminated on RJ45 ends but used entirely proprietary signalling. Some of these would actually have worked with the splitters you bought too because you could set up the live pairs on the PBX and phone so that each phone only used one pair and ignored the rest.