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Back in the day, when Wi-Fi routers weren’t as popular, you would find most people using RJ45 Ethernet cables to connect their computers to the internet. Even now, lots of users default to a wired internet connection when they want a reliable setup with no network drops. For instance, gaming setups, workstations, and servers work without any interruptions when connected to the internet via an Ethernet cable. That’s also a big reason why brands sell specific Ethernet cables for gaming, tangle-resistant flat Ethernet cables for better cable management, and even blue Ethernet cables for a distinct look in commercial setups. If you’re confused with so many cable types, don’t worry — you’ll be relieved to know that SlashGear has a guide on how to choose the right Ethernet cable for your computer.

If you already have a few of these RJ45 cables lying around, there’s actually quite a lot that you can do with them apart from connecting your computer to the internet. For example, you can connect a printer to your computer via an Ethernet cable instead of using Wi-Fi or USB. Similarly, you can share your computer’s internet connection or even transfer large files that would otherwise take a lot of time. So, whether you have a PC or a laptop that has an Ethernet port that’s not in use, here’s how you can repurpose it without using it to access the internet.

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If you’ve ever tried to move 4K video files, or large backups, or anything that’s made up hundreds of gigabytes of data between two computers, using Wi-Fi to do it can take hours. USB flash drives, or even the fastest portable SSDs, require you to first copy the data from computer and then paste it on the other, adding unnecessary time to the process. If you’re looking for a more seamless solution, your Ethernet port offers a more direct, faster alternative. Simply plug an Ethernet cable directly into the ports of both computers. Thanks to Auto-MDIX technology present on most network cards from the last decade, the connection is automatically configured. Next, dive into the network adapter settings on both PCs to manually assign them static IP addresses on the same subnet, such as setting the first PC to 192.168.1.1 and the second to 192.168.1.2, both with a subnet mask of 255.255.255.0.

Once configured, enable file sharing in Windows or macOS, right-click the folder you want to transfer, and share it with the local network. You can then access it from the other machine by typing the IP address into your file explorer. This method is advantageous because it bypasses your router, meaning the transfer isn’t slowed down by other devices streaming or gaming on your network. A standard Gigabit Ethernet port will give you transfer speeds of up to 125 MB/s, but if both of your machines happen to have 2.5GbE or 10GbE ports, you can achieve speeds of up to 300 MB/s or 1.2 GB/s, respectively. This is undoubtedly one of the fastest and most secure way to send large files between two computers.

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You may find yourself in a situation where your PC has a fantastic internet connection via your home or office Wi-Fi router, but you have another device, like an office laptop or an old desktop PC without a network card, that lacks Wi-Fi capabilities. In these scenarios, you can use your PC’s Ethernet port to share its internet connection — effectively turning your computer into a makeshift router or personal hotspot. You can do so by plugging one end of your Ethernet cable into your PC that’s connected to the internet, and the other into the device that needs internet access. On Windows, navigate to the Network Connections panel, right-click the adapter that currently has internet access, and select its properties. Under the Sharing tab, simply check the box to allow other network users to connect through this computer’s internet connection and select your Ethernet adapter from the dropdown menu.

Your PC will instantly begin routing internet traffic to the connected device. This trick is an absolute lifesaver in hotels or other public places that use captive portals with web logins. Some devices like portable gaming consoles or even older smart TVs may struggle to load the login screen, but you can still use this method by using a USB-C to Ethernet adapter. This way, you only have to authenticate the connection on your primary device. Furthermore, if your router is too far away for your device to get a good wireless signal but your PC has a powerful, high-gain Wi-Fi antenna, using your PC for tethering provides a much more stable, hardwired connection for lag-free gaming or streaming.

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A Network Attached Storage (NAS) device is essentially a personal cloud server for your home or office, typically plugged into a central router so that any device on the network can access its contents. However, if you are a solo creative professional, like a video editor or a music producer, you might want to bypass the network entirely and hardwire the NAS directly into your workstation for maximum performance. After all, you’re going to be the only one accessing the stored files. You can achieve this by plugging an Ethernet cable directly from the LAN port on the back of the NAS into the Ethernet port on your PC. Just like the PC-to-PC file transfer method, you need to ensure both devices can communicate by assigning them static IP addresses.

Access your NAS’ control panel to assign its Ethernet port a static IP like 10.0.10.1. Then, head into your PC’s network settings and assign its Ethernet adapter an IP address in the same range, such as 10.0.10.2. You can then seamlessly map the NAS drives directly in your operating system using that IP address. The primary advantage here is fast speeds. Many modern NAS enclosures come equipped with 10-Gigabit Ethernet (10GbE) ports, and utilizing those speeds over a traditional network would require purchasing an expensive 10GbE network switch and upgrading your router. By wiring the NAS directly to a 10GbE PCIe card in your PC, you save hundreds of dollars on networking equipment while ensuring that large transfers are never bottlenecked by network traffic from other users in the house.

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Printers are some of the most user-unfriendly devices out there. We’ve all experienced the frustration of a wireless printer mysteriously dropping its connection right when a document urgently needs to be printed. While most network printers are designed to be connected to a router to serve the entire home or office, you can actually wire a network printer directly to your PC’s Ethernet port to create an ultra-reliable, isolated printing station. To set this up, connect the Ethernet cable from the LAN port on the back of the printer straight into your computer. Next, use the screen on the printer to navigate to its network settings and turn off DHCP. Then, manually assign a static IP address, such as 192.168.8.60. You will then need to match this subnet on your PC by going to your Ethernet adapter settings and setting a static IP like 192.168.8.61.

Finally, when adding a printer in your PC’s settings, bypass the automatic search and choose to add it manually using a TCP/IP address. Enter the printer’s static IP to let your OS install the necessary drivers. You finally have a reliable printer setup since a direct connection eliminates the need for troubleshooting associated with printers dropping off the network. Furthermore, this is an excellent setup from a security standpoint. If you are printing sensitive documents, legal contracts, or confidential client data, keeping the printer completely off the grid ensures that nobody else can access the printer’s memory.

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If you use two computers side-by-side, managing two separate keyboards, mice, and other peripherals can clutter up your desk and affect your workflow. A hardware KVM switch solves this, but they are often expensive and can end up causing a cable mess. Software KVMs, on the other hand, allow you to share one mouse and keyboard across multiple computers, and (you guessed it) you can run it over an Ethernet connection. Connect an Ethernet cable between the two computers and configure static IP addresses on both machines’ Ethernet adapters so they share the same subnet. Note that you will have to keep both computers connected to the internet via Wi-Fi. 

Next, install a software KVM solution like Barrier or Mouse without Borders. Designate the PC with the physical keyboard and mouse as the server, and point the second PC to the server’s static IP address as the client. While you certainly can run software KVMs over your home Wi-Fi, doing so may introduce latency issues or micro-stutters, especially if other users at home or in your office are also using the router. By routing the software KVM through a hardwired Ethernet connection, you can ensure the latency is pretty much zero. The end result is more space on your desk, cost savings from not buying a hardware switch, and a seamless way to move your cursor between computers.