The Internet speed at home is slow, how can I tell if the speed is limited by the router? The house I rented was affected by this trick, and I found the root cause of the disease in five minutes after searching the backstage.

This happened when I was renting an apartment. The first night I moved in, I felt something was wrong with the internet.: The router left by the landlord is a Tenda AC10, and the broadband is 300M, but when I checked the speed of my mobile phone over and over, it was just over 30M. I can make do with watching videos, but sending a file can make people anxious to death. My first reaction was that the broadband was falsely marked, my second reaction was that the router was old, and my third reaction was that the mobile phone network card was not working - one in each of the three directions, nothing. Finally, in an inconspicuous corner of the router's background, I found a speed limit rule. My mobile phone was limited to 30M by the previous tenant. Delete the rule and the speed test goes directly to 287M.

After that, I helped two friends check for the same problem. One was because the elderly at home set a speed limit and forgot about it because he was afraid that his children would be addicted. The other was because the installer "kindly" evened out the bandwidth for each device before he left. What these things have in common is that: People who are speed-limited don’t know it. The symptoms are exactly the same as "slow network". They are especially prone to thinking about the aging of the broadband and router, and they are wasting their money. . I have written an article before about how to limit the speed of a device. How does the router limit the speed of the device? , from the perspective of "I want to limit others" ； This article, on the other hand, writes from the perspective of "I am restricted", how to find it, where to find it, and how to delete it.

First distinguish: The speed limiter "slow" has a face, which is different from other slows.

There are many reasons why the Internet is slow, but slow speed has a very unique appearance. I will compare it with several other common slow methods. You can check the symptoms first.:

The key is the first one: 「fixed value」 . The speed limit rule is a hard upper limit. The router will cut the traffic of your device until it does not exceed the line, so what you measure is a flat line - the 300M broadband is limited to 30M. If you measure it ten times, the ten times are between 29 and 31. The fluctuation is abnormally small. However, the slowness due to "physical reasons" such as broadband congestion and poor signal fluctuates. It drops to 50M during peak hours and returns to 280M in the middle of the night. The curve is alive. That's what got me convicted the night I rented a room.: After six consecutive measurements, they were all around 30M, and the standard deviation was as small as if drawn with a ruler.

There is also an auxiliary judgment method: Change equipment test . Most of the speed limit rules take effect based on the device (MAC address). Your mobile phone is limited. Take your wife's mobile phone and a WiFi to test it. She has a full speed of 30M against you, so it is basically limited based on the device. If all the devices in the home are limited to the same number, it is the speed limit of the whole machine or the total QoS limit. In the case I encountered myself, the installer's "good-intentioned equalization of bandwidth" meant that each device in the family was limited. On the other hand, if someone else's phone is faster but yours is slower, don't be quick to doubt the speed limit. First check to see if you are connected to the 2.4G band. If the band negotiation rate drops, it means "you are the only one who is slower". How to locate who is using bandwidth The ideas in that article can be directly transferred.

Set the speed test posture correctly first, otherwise it is easy to accuse the router unjustly

Before turning to the backend, you must first do a solid job in speed measurement, otherwise the data will be inaccurate and it will be embarrassing for a good router to be wronged. three rules:

First, Test again using network cable and WiFi . WiFi itself has losses. It is normal for 300M broadband wireless to measure 240M, but if it is wired to measure 30M, it is a flaw. Later, I checked the order for a friend. He had been using his laptop to test wirelessly, and the speed was 290M. The instant the Internet cable was plugged in, it was 30M. The limit was due to the rules on the wired side, and there was no limit on wireless. The couple almost bought a new router for this. Wired speed measurement can best reveal the speed limit.

second, Tested more than three times in a row during the same period . A single speed measurement is greatly affected by fluctuations, and the speed limit is determined by "stability." You cannot see the fixity after a single measurement. Three values ​​squeezed into a small narrow band (such as 29.6, 30.2, 30.4) are the face of the speed limit.

third, When measuring speed, don’t let other devices grab the network . If someone at home is watching videos or uploading to a network disk, the number you measure will be lowered. That means you are really "robbed", not restricted. How to find devices that are using traffic? Three steps positioning That article is very detailed, so read it first and then come back to test it, so that the data will be clean. In addition, it is best to use a tool recognized by the operator to measure speed. Specifically, which one is accurate and which posture counts? Troubleshooting that Gigabit only runs 200 The first section is about this.

Take a small notebook and write down the numbers after measuring.: Device name, wired or wireless, three values. Check the background later to find the rules for the device name.

Five backends, where are the speed limit rules hidden?

Below are the five backends I have visited. The locations are different but the ideas are the same.: Advanced device list, then click on the details of your device and look for words like "speed limit" and "speed limit". The premise is that you can enter the backend - if you don't know the password, first look at the sticker on the back of the router, and then read the note left by the installer. If it doesn't work, you can only reset (at the cost of reconfiguring the entire house). MAC clone article I talked about the problem of changing the machine and reconfiguring it. Resetting is just as painful. If you can’t get to this point, you won’t do it.)

I will talk about a few places that are easy to miss. One is 「Master switches such as "intelligent speed limit", "QoS" and "bandwidth allocation" ： They are not rules for a single device, but the router itself dynamically allocates bandwidth according to "who is more important and who takes priority." The characteristic of this kind of restriction is that "you are suppressed during peak periods, and you are at full speed during idle periods." There is no fixed value. If there are gamers at home or those who have implemented children’s Internet access control, this switch is most likely to be turned on - there is an article on the site about hardware acceleration that mentioned, Some people upgraded to Gigabit and only ran 400 Mbit. , and finally found that it was the parental control function that was holding me back, the same kind of thing. It's easy to verify: Turn off QoS or smart speed limit for ten minutes, then measure the speed, and the number will rise immediately.

The second is Speed ​​limits in children’s Internet control . It is very common to set "Internet time periods" for children's tablets. Some brands' control packages come with "speed limits during non-study periods." The rules are in child control instead of device management, and you can't find them when browsing the device details. If you have children or elderly people at home, remember to click on this menu and take a look. My friend's mother-in-law set up a "slow homework time" setting on her grandson's tablet, and the adults fell victim to it as soon as they used the tablet.

The third is The mobile App and the web backend are not the same view . Rules that are not visible in the background of the web page may be visible in the App, and vice versa. When turning over, read both sides, don't just believe one side.

After finding the rules: Delete it cleanly, don’t leave any tails

Deleting the rule itself is a trivial matter. Click delete, save, restart the WiFi connection (without restarting the router), and then test the speed to verify. But it’s easy to keep three tails:

The first tail, Black and white lists and speed limits are two systems . Some people find that while being speed-limited, they also find that they have been "blacklisted" (during periods of disconnection). Even if they delete the speed-limiting rule, they are still disconnected. That is another rule of the blacklist, and it is deleted in two places. How to separate these two sets, and how to get them back if you pull them wrongly? The article about blocking equipment Let’s talk about it all and deal with it accordingly.

The second tail, After deleting, the speed test is still slow . That means the speed limit is just a superficial layer, and there are other problems underneath. Check down in order: Whether the network cable is a 100M crystal head (a four-core cable will drop 100M when running Gigabit), whether the optical modem is plugged into the 100M port, and whether the broadband package is really enough - these three layers are exactly Troubleshooting article for gigabit broadband only running 200 The main line is passed layer by layer. There is also a hidden one: The mobile phone is connected to 2.4G, and the negotiated speed itself is only one to two hundred Mbits. In this case, even if the speed limit rule is deleted, it will not make any difference. The frequency band issue must be resolved first.

The third tail, After deleting it, it slowly comes back after a few days. . Two possibilities: Either someone at home added the rules remotely on the App (now all Apps can remotely manage it, Mobile phone remote management I wrote about the principle in that article, but the converse is that "others can remotely change your router") ； Or it is a dynamic rule like "smart speed limit", which has no fixed value but will continue to suppress your device. The former made it clear to his family, while the latter simply turned off the main switch. This is one of the reasons why I recommend keeping the router management password yourself. The default password left by the installer can be set by anyone. Change management password It is the first thing you do after moving into a new house or renting a house.

One minute of self-examination to wrap things up

Condensing the entire process into a table, you can start now:

When I rented a house, I spent three nights going from "thinking it was a false broadband standard" to deleting the rules. ； Later, I checked it for a friend, and I was convicted in ten minutes - it's not that I have become better, but that the "fixed speed measurement value" feature is too sharp. Once you know what it is looking for, the speed limit rules cannot be hidden in the background. When the Internet is slow, don’t rush to blame the broadband or change the router. First, take a minute to test the speed three times.: Numbers are alive, questions are on the line ； Numbers are dead, and the problem is probably a forgotten rule lying in the background.