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Is your router holding back your fiber internet speeds? How to make sure your network isn’t a bottleneck
You just signed up for one of the fastest fiber plans your provider offers, promising speeds of 5 Gbps or more. But when you connect your laptop or phone, your internet still feels frustratingly slow. It’s easy to blame your internet service provider (ISP) for the underperformance, but the problem could be sitting right in your home: your router.
Your WAN port might not be fast enough to handle your plan, or your router could be using an outdated Wi-Fi standard that puts a ceiling on your speeds. Before you log a complaint with your ISP, it’s worth checking whether your router is actually the bottleneck.
Here are the router-related factors that can hold back your internet speeds, along with what you can do to fix them.
WAN ports
One of the most common reasons for slower internet speeds is an undersized WAN port. Even if your internet provider offers a 1 Gbps plan, if your WAN port doesn’t support it, you’ll be getting much lower speeds than that.
Even on a gigabit Ethernet connection, 6% of the speed is consumed by frame headers, gaps between frames, and TCP/IP headers, giving you a throughput of around 940 Mbps before anything else goes wrong. Thus, you’ll first need to ensure that your WAN port supports the high internet speed offered by your provider.
Data from OpenWorld shows that gigabit-tier subscriptions grew 29% year over year, and around one-third of subscribers in the U.S. are now provisioned for gigabit speeds. ISPs are also now designing routers around this problem.
Along with WAN, another thing you need to pay attention to is the LAN port on satellite nodes. Many Wi-Fi 7 mesh kits have a 2.5 GbE WAN port but only a 1 GbE LAN port, which can cap your satellite throughput at about 940 Mbps again.
To put it in a nutshell:
- If your internet plan speed is up to 900 Mbps, you need a 1 GbE WAN port.
- If your speed ranges from 1 to 2.5 Gbps, you will need a 2.5 GbE port.
- Above that speed, you will need a 10 GbE port, along with a matching LAN port and cabling.
Outdated Wi-Fi standards: the wireless ceiling
As per a recent survey conducted by Ookla, four Wi-Fi generations dominate the U.S. market. Wi-Fi 4 has a share of 13%, whereas Wi-Fi 5 registers a 33% share. Wi-Fi 6 has by far the largest market share, with 52.3% of U.S. consumers relying on it, whereas Wi-Fi 7, which came along in early 2024, had grown to just 1.8% by the first quarter of 2025. This means that 7 in 10 connections in the U.S. are still on Wi-Fi 5 or older.
The same report also outlines the median download speeds on all four standards. Wi-Fi 4 registers the lowest speed at around 41.6 Mbps. Wi-Fi 5 shows a speed of 226.66 Mbps, whereas Wi-Fi 6 clocks at 374.76 Mbps.
So, even if you have a 1 Gbps plan from your internet provider, using any of the three older Wi-Fi standards would not deliver the highest maximum speed promised by your provider.
Wi-Fi 6E is a considerable improvement over the earlier Wi-Fi 6 standard, clocking median download speeds well above 700 Mbps, whereas the latest Wi-Fi 7 offers a median speed of 764.15 Mbps.
These are all median figures, and the exact speed will depend on the provider you choose. This begs the question: do you need Wi-Fi 7 for gigabit speeds? Not necessarily. While users can get speeds of 1 to 4 Gbps on Wi-Fi 7, for most homes on gigabit or slower plans, Wi-Fi 6E is still enough.
The dual-band problem
Even if you have a decent Wi-Fi connection, there’s the old “802.11 performance anomaly” that can slow down your internet. Wi-Fi works like a single lane instead of a four-lane highway. Only one device can transmit on a given channel at a time, and each device has to check if the airwaves are clear before it sends anything.
Now, this was okay when households used to have one or two devices. However, as Park Associates highlights, an average U.S. internet home has around 17 connected devices, including smart TVs, smart doorbells, game consoles, plugs, and thermostats, and each one of them is queuing up for the same airtime.
And on a dual-band router, they all have to squeeze into the 2.4 GHz and 5 GHz bands. What’s worse is that the slowest device can bring down your internet speed even for the fast-performing devices. This happens because Wi-Fi routers give each device an equal turn to process the data.
However, a 6 Mbps device can use up to nine times more airtime than a 54 Mbps device to send the same amount of data, and the total network speed would collapse to 6 Mbps.
The two bands are also pretty tight on space. The 2.4 GHz band has only three non-overlapping channels: 1, 6, and 11. Whereas the 5 GHz band has more room, it fills up quickly when routers bond channels together for higher speeds.
This means that if you have a lot of devices, especially older ones that are slow and hog up a lot of your Wi-Fi airtime, your overall connection speed would drop, even if you have the latest router or the highest-speed offering.
Here’s what you could do:
- Move smart home devices to 2.4 GHz and keep fast devices on 5 or 6 GHz using separate network names.
- On 2.4 GHz, pick channel 1 or 11 rather than 6. Channel 6 is a common default and often the busiest, so check which is quietest in your home with a free Wi-Fi analyzer app.
- Turn on airtime fairness if the router offers it. Some routers offer this function so that slow devices do not hog your connection.
This is why Wi-Fi 6 introduced Orthogonal Frequency-Division Multiple Access (OFDMA), which lets the router accommodate various devices in a single transmission instead of queueing them up.
A tri-band router might help you if it adds an additional 6 GHz band instead of a second 5 GHz one. In the U.S., 6 GHz adds around 1,200 MHz of fresh spectrum. Even better, older devices cannot use it at all, so it stays uncongested.
Router processing limits
Your router necessarily decides what to do with every piece of data that passes through it, and it has limited processor capacity for this purpose. Modern routers can get around this with the help of built-in speed-boost chips, such as NAT acceleration or hardware acceleration.
However, there are some features that force the router’s processor to inspect every piece of data, which bypasses the speed-boost chip. These include virtual private networks (VPNs), some traffic management (QoS) settings, firewall rules, and security scanning.
For example, routers cannot handle VPN encryption as fast as computers can. So, running a VPN on your router can reduce speed and add delays. For instance, a user getting 1 Gbps fiber speed saw speeds fall to 220-250 Mbps with the router’s OpenVPN client switched on.
This is why it’s recommended to switch off the features you don’t use, such as bandwidth limits or built-in security scanning, and run a VPN on your laptop or phone rather than on the router.
Out-of-date firmware
Just like your phone, your router also runs software called firmware that must be regularly updated to fix any bugs and security vulnerabilities. However, most people never install these updates.
In a Consumer Reports survey, it was found that two in five Americans weren’t even sure when their router was last updated. Make sure that you check your router’s app or settings page for any new updates and turn on automatic updates if your router offers them.
Using the wrong port
The router you use often has one fast port and other slower ports. For instance, Google Fiber’s multi-gig router has a single silver 10-gig port, and the other ports top out at one gig.
So, if you have plugged your device or router into one of the slower ports, you’ll never get more than 1 Gbps of speed, no matter how fast your plan is. Look for the port labeled 10G, 5G, or 2.5G (it's often a different color) and use that one for your main connection.
How can you test your internet speed?
Before checking the speed your internet provider is offering, you’ll need to ensure that your testing environment is well prepared. Pause all activities that consume a high level of internet bandwidth, such as downloads, streaming, cloud backups, or game updates.
Then plug your computer directly into the provider’s equipment with an Ethernet cable without using your router or any other equipment. This way, you’ll get the actual speed your ISP offers and is able to deliver.
Next, plug the same device into your router with a cable and test again. If the speed comes out lower than the direct Ethernet cable test, it is likely that the router is the bottleneck.
Additionally, you’ll need to test multiple times, as a single reading does not give conclusive evidence of lower speeds. Test next to the router and then in the rooms where you actually use the internet, and compare both with your wired results. For example, on a gigabit plan, you can expect speeds of 400-700 Mbps over Wi-Fi.
Also, if you are on a multi-gig plan, you’ll need to run the speed test on the Speedtest app rather than in the browser, since many browsers top out at about 3 Gbps. So, it might not show you your actual full speed.
How to troubleshoot slow internet due to the router?
If you’re experiencing slow internet speeds and want to ensure that your router isn’t the culprit, here are some troubleshooting steps you can take.
- Restart your router: This is often the simplest fix and can clear out any glitches that build up in your router over time. The FBI and the NSA now recommend rebooting your home router at least once a week.
- Move it to a better spot: Place your router in a central location, high up on a shelf rather than on the floor. Keep it away from thick walls or metal objects. Every obstruction between you and your router can cut down the Wi-Fi speed.
- Keep the firmware updated: If you have not updated your router’s firmware in a long time, check your router’s app or settings page for updates and turn on automatic updates if it offers them. These updates can fix any bugs that might be slowing down your connection.
- Turn off features you don’t use: Features such as bandwidth limits, traffic monitoring, or VPNs can switch off your router’s speed boost. Turn off any features that you’re not actively using and consider running a VPN on your device rather than on your router.
- Use the fastest port and the right band: Make sure to plug your main connection into the port labeled 10G, 5G, or 2.5G, depending on the router you’re using. On Wi-Fi, connect to 5 GHz or 6 GHz when you’re close to the router and leave the 2.4 GHz band for smart home devices with older firmware.
- Turn on bridge mode or IP passthrough: If you’re using your own router along with your provider’s box, you’ll need to use the IP passthrough setting. This hands the connection straight to your router instead of passing it through the provider’s equipment, which might lead to better speeds.
- Replace your old router: If your router is old and you’re already stuck on Wi-Fi 4 or Wi-Fi 5, it might be time to upgrade to a new Wi-Fi standard, preferably Wi-Fi 6 and above.
- Rerun the tests: After you have ensured that there’s nothing on the router’s end that could lead to speed slowdowns, rerun the speed test and check the results. If the speed still comes out lower than what the ISP advertises, reach out to your provider with the issue.
Bottom line
Your ISP might not always be at fault for slow internet speeds at your home. Your router could be the culprit for various reasons. For starters, it might have a lower-speed-capacity WAN port that simply does not support your high-speed plan. Or you might be using an older router with Wi-Fi 4 or Wi-Fi 5, which does not support higher speeds.
Moreover, you might have multiple household devices that may hog the 2.4 GHz and 5 GHz bands on your Wi-Fi, or your router’s firmware may simply be out of date and contain bugs and vulnerabilities.
Ensure that you check your router before reaching out to the ISP. Restarting it can be a good solution that might fix any glitches. Additionally, keep your firmware updated and turn off features you do not use, such as VPN or bandwidth limits, which may slow down your speeds.
Also make sure that you use the fastest port for your main connection. However, if your router is old or you are still using Wi-Fi 4 or 5 for multi-gig plans, it might be time to upgrade to Wi-Fi 6 and above.