What is the 2.5G Ethernet port on a router used for?

There are many obvious and hidden benefits of fiber optic internet. One of the big benefits of its development is that multi-gigabit home internet has become a reality across the country: You can get speeds of eight gigabits per second (Gbps) from Google Fiber in the city or through Greenlight Networks in the mountains and lakes of upstate New York. With that kind of power, you need the right equipment and know-how to use it, including those new 2.5G Ethernet ports on your modem and routers.

As their names suggest, 2.5G and 2.5GbE Ethernet ports offer speeds of up to 2.5 gigabits per second between two points. It’s a happy medium between the 1G port you’ll see on your home modem and routers and 10G Ethernet, which requires more infrastructure and is primarily used in enterprise networks. That said, you may find faster 5GbE ports on some high-end routers. 2.5G and 5G Ethernet were incorporated into a 2016 revision of the Ethernet standards governed by IEEE Part 802.3 – yes, you probably know Part 802.11 as the overall specification for Wi-Fi. But what exactly can you do with 2.5G Ethernet? And what do you need to benefit from it?

Obviously, you need to check your modem, routers, and terminals to see if they support 2.5G Ethernet. Ports should be clearly labeled with their rated speeds. This is the easy part.

As for actual connections, 2.5G and 5G Ethernet can run over cables designed for 1G home internet use. Keep in mind that we are talking about twisted copper wires which may or may not be shielded from interference. Generally speaking, this means that an Ethernet cable must be able to deliver its best speeds over short, straight spaces, and that connection quality can be hampered by excessive length and curves in the path. Cable manufacturers typically promise rated speeds over a maximum distance of 328 feet or 100 meters.

Ethernet cables are classified by speed rating. Ideally, you would want to find Category 6 or 6a cables if you plan to use 2.5G or 5G near the 328 foot limit. They are designed to deliver gigabit speeds over their entire length and up to 10 Gbps at approximately 120 feet, depending on cable routing and conditions. That said, some users have reported on Reddit that they were able to achieve speeds of 2.5Gbps over Category 5e and 5 wires over shorter distances. If you are checking the installed cable, be sure to look for any screen printed or embossed printing identifying its speed category.

A 2.5 Gbps internet connection is excessive for many of today’s high-demand tasks, like 4K or 8K streaming, which maxes out at 120 megabits per second (Mbps), and competitive or cloud-based gaming, where latency is the most pressing issue. However, if you regularly move large files across the web to your PC or, better yet, to a home server or NAS, a 2.5G connection will allow you to move terabytes across space much faster than ever before. Content creators and torrent users may find this particularly useful. You can also get a shorter Ethernet cable for smart use: connecting your PC to another computer or local storage or anything else you can directly connect with. You’ll never experience a file transfer the same way again.

Of course, there’s always the classic mission of a pair of humble RJ45 connectors: bringing your 2.5Gbps Internet to the other side of your house. Once there, you can connect to a Wi-Fi router so you can use your phone in the bathroom.