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

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: Buy a TP-Link 5 Port Gigabit Ethernet Switch: lmg.gg/lp5ev Buy a TP-Link 5 Port Ethernet Switch: lmg.gg/3F5f5 Purchases made through some store links may provide some compensation to Linus Media Group.

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...

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

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.

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! 😂

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.

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. :)

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.

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 👍

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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

I've been using 100Base Ethernet cable splitter pairs quite successfully for years. Yes, they work the way that your made yours. Thank you for explaining important considerations, limitations, and how they work! Here's why I use them: A good application for a 100Base Ethernet cable splitter is in a managed network that has Mode A PoE clients located in extreme temperature environments away from a local power supply. Although weatherized industrial PoE-powered managed PoE switches are available for use in such applications (e.g. PoE security cameras, especially where you have a cable to one camera and need to add a second camera nearby), the cost of these switches is much higher than the indoor switches in your links. Adding a managed switch can add additional maintenance needs (unless it is an automatically maintained network, which can also drive up the cost of the switch) and it adds another point of failure (including attracting possible theft of an outdoor switch that costs more than a the equipment connected to it). The passive cable splitter pair never requires maintenance, it requires no power, it is compact, it's extremely reliable in harsh environments, it can consolidate network device surge protection to one end, and it's very inexpensive. For 100Base Ethernet Mode A PoE, it just works and keeps on working.

Even back in the 90s I was able to buy working 10Base-T splitters that properly split the pairs to yield 2 connections. First supplier in mind was BlackBox, supplier of many amazing doohickeys for various types of serial and network connections. Nothing at all new about this stuff. I even had the occasion to split jacks on a single pull, as you demonstrated. I punched 2 pair into one jack and 2 pair in the other at both ends of a single CAT5 line. Done properly it worked like a charm for 10Base-T and even 100Base-T with enough twists per inch cabling. BlackBox also made wall jacks for this purpose, where all you had to do was punch the wires the same way on both ends as indicated on the jacks' punchdowns. I had a cabler test one of my own such connections with his Fluke, and they both tested okay for 100Mb, but that's not the same as two full connections lighting up all eight wires at once. I'm sure such a contraption wouldn't rate anywhere near good enough for 1Gb, even with great care with the tight pair twists in CAT6e. In the installations I directed I made damn sure to use professional cablers, good cable, good jacks and blocks, and tested-to-spec 568B connections. I always pulled extra, so need 1 but pull 2, 2 pulls 3, 3 pulls 5, etc. I also only terminated 568B, even for phones. Our phones were 4-wire links, and with either 568A or 568B the 2 center pair tracked for 4-wire phone systems. The jacks we used were also shouldered to properly hold either an RJ45 or RJ11 or RJ14 plugs. We used those lines for Ethernet, telco, and even serial with RTS/CTS and even a few times DTR/DSR...I wired my own RJ45 to DB9 and DB15 connectors for such things so I could use even 568B patch cables for serial printers. Those were the days. I'm surprised anyone sells such crap as you found. The plans for proper Ethernet splitters are still out there, and aren't even that arcane. I'd be shocked if there weren't already PCB prints ready to go with minimal case requirements. You could even build a hub or switch into a case of that size, provided it could also pull power from maybe a USB. The trick then would be whether the network switch on the other side permits switches or hubs, which in any business office they SHOULD NOT without an exception process through the networking owner. No secret guest connections.

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.

As an electrician, I've always used (network) switches for connecting devices, however, the splitters work great for use in lighting control devices wired with Cat5E. Send power to a power pack module then Cat5e to a sensor or wall switch or another power pack. Splitters started coming with ceiling occupancy sensors awhile ago making installation easier.

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.

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 bigger.......

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

2:39 It'll also lower the impedance presented to the headphone amplifier quite significantly if multiple low impedance headphones share a single headphone jack (assuming all headphones are connected in parallel); this could cause the amp's protection circuit to kick in or (if there isn't any protection) damage the amp.

While working in the business of networks and telecommunications I can confirm he's right. Those fake splitters had a use back in the days for some connection types, like an analogue telephone line or even ISDN lines. But it's really no use in computer networks. You'll need a real splitter like he described in the video. I also want to comment that it's a good sum up of the topic even for people not having a deep insight in networks. 👍🏼