What does the Mercury Tenda router network port light mean? A small light can detect Gigabit or 100Mbps, whether it is connected or not, and it can even catch a thief if it flashes wildly in the middle of the night.

I got up at two o'clock that night to go to the bathroom. I passed by the TV cabinet and glanced at the router. The light on the WAN port flashed as if my heart had stopped. The frequency was so fast that it was blinding. Everyone in the family is asleep, who is running traffic? I stood there and watched for half a minute, and suddenly I realized something: I see this row of small lights every day, but I have never really understood what they are reporting. The next day, I did an experiment with the Mercury D191G at home and the smaller Tenda AC10. I plugged and unplugged the wires one by one and checked every state. I even caught a computer secretly uploading data using this light. This article explains the basics of Mercury Tengda network port lights in one go.

Check out the lights first: This row of lights is completely different from the SYS lights.

The lights on the router panel are managed by two groups of people. The SYS light and WiFi light are lit by firmware, and the router's system controls them, so some models can turn them on and off in the background. The network port light is different; Directly driven by the switching chip , whichever port the data passes through, the light of that port flashes, and the system level does not handle it at all. This distinction has practical consequences: I searched through the backend and couldn't find the option to turn off the network port light. I thought it was too bright so I had to stick it on. How to turn off the indicator light if it is too bright? In that article, I tried five backends and all came to the same conclusion.

The network port light layouts of Mercury and Tenda are basically the same.: Each network port corresponds to one or two small lights. The old machine has one port with a single color light ； The new machine with a speed indicator has two lights on one port - one to tell "communication and activity", and the other to tell "whether it is running Gigabit or 100M." WiFi6 machines like the Tenda AX12 have two WiFi 6 chips, the Mercury D191G also has two WiFi 6 chips per port, and the old AC10 that I have made has only one WiFi 6 chip. Before looking at the lights, count the number of lights in each port of your machine. The interpretation method will be different later.

There is another confusion that is easy to make: The flashing rhythm of the network port light is completely out of sync with the SYS light. The SYS light flashes slowly every second, which is the system heartbeat. ； The network port lights are data-driven. If there is heavy traffic, they will flash together, but if there is no traffic, they will be basically quiet. Some people see the SYS light flashing slowly and think the machine is going down, and see the network port light flashing wildly and think it is hacked. Both are false alarms. The division of labor between the lights must be clearly distinguished first. Mercury indicator light meaning and Tenda indicator light meaning The two articles cover all about panel lights, and this article focuses on the row of network ports.

Four state interpretation: What does it report if it is always on, flashes quickly, flashes slowly, or does not light up?

A single network port light has three states, plus "off" counts as four states, let's talk about them one by one.

Always on ： There is a device plugged into this port, the link has been negotiated, and the physical connection is open. Note that the constant light only means "pass" and does not mean that there is data flowing. When your NAS is in standby, the light on that port is basically always on, and the light is still on when the hard disk is asleep. This is normal, and don’t think that the flow is cut off.

flash mob ： Data is passing through this port. The frequency of flashing is directly related to the amount of traffic. When the download is full, the light is almost always on, but when the traffic is low, it will jump a few times sporadically. I saw a certain light flashing wildly in the middle of the night. It wasn't because it was haunted, but because the device connected to this port was transmitting data.

Flash slowly or jump occasionally ： Trace data is usually background noise such as device keep-alive packets and ARP broadcasts. Late at night when all the equipment in the house is on standby, the network port light blinks occasionally, which is so normal that it can no longer be normal.

Not lit ： There are two situations: one is that the port is not plugged in, or the line is plugged in but the peer device is not powered on, the link is not established, and the light is not on. The other is that the cord is plugged in, the device is on, but the light does not come on, then there is a problem, which will be discussed separately later. Remember the first iron rule of interpretation first: A port that doesn't light up doesn't necessarily mean it's bad, and a port that lights up doesn't necessarily mean it's clear. ——When the negotiation was at the bottom of 100Mbps, the light was still on, but the speed had dropped.

Two-color rate light: Green Gigabit and Orange 100M, one light saves a trip to the backstage

For models with two lights, the second one is the speed light. The rules for Mercury Tengda are the same.: Green is Gigabit negotiation, orange is 100M . This light is my favorite zero-cost physical examination tool. The Gigabit broadband home speed test card is 94 MB. First, I squatted down and took a look at the color of the speed light on the WAN port. The orange color basically solved the case - the negotiation dropped to 100 MB. LAN port speed article Here I calculated the 100M port in detail. The machine itself is a 100M port. If this light is orange, it is the final verdict.

But there are two situations where this lamp will "lie", so you have to be careful. The first is that the network card of the device plugged in is a 100 Mbit/s, or the network cable is a four-core one. Gigabit cannot be negotiated, and the machine light on the Gigabit port is still orange. The light did not lie at this time. It is someone at both ends of the link that is holding back. You can tell whose fault it is by changing the port on your laptop and plugging it in again. The second type is the most negative: The wire cover is printed with Category 5e, and the core wire is a fake copper-clad aluminum wire. It can negotiate Gigabit over a short distance. The light is green, but the speed cannot go up. This requires a speed test. Speed ​​test posture The rules in that article must be correct before drawing a conclusion.

The old AC10 I used when I was little had one port and one monochromatic light, and no speed light. This kind of machine can only go to the backend if it is judged to be 100M or 100M.: Mercury enters 192.168.0.1 or melogin.cn , Tengdajin tendawifi.com , click on the status details of the corresponding network port in "Device Management" or "Running Status" and look at the line "Negotiation Rate". There is also a faster view on the computer side: In Windows, right-click the network icon on the taskbar, click "Network and Internet Settings" and click Ethernet. The "Link Speed" on the status page says 1000/1000 means Gigabit, and 100/100 means it is suppressed. It only takes three minutes to look at each other.

That light flashing wildly in the middle of the night is my old buddy who catches traffic thieves.

Back to that night at the beginning. The WAN port light flashes wildly, indicating that a device is using external network traffic. Want to know who it is, the method is stupid but effective: Look at which light of the LAN port flashes together. . The WAN port and a certain LAN port flash wildly at the same time, and the traffic goes out from that port - the device plugged into that port is the suspect. My house has a simple structure. There are only four wires under the TV cabinet and router.: Desktops, NAS, TVs, switches. What flashed that night was the desktop port. I checked the next day and found that the automatic synchronization of a certain network disk client was turned on, uploading all the more than 40 GB photos I had inserted the day before. The process is turned off and the lights are on the spot.

This method of catching thieves is suitable for households where the wiring is clearly connected. Each port corresponds to a fixed device and can be identified at a glance. If all devices are relayed through a switch, and only the switch port can be seen flashing on the router, you have to go to the switch and continue looking, layer by layer. By the way, if you want to see how much traffic each device is running, there are numbers in the background device list. Xiaomi’s article checks 100MB The idea is the same. You can also see the status page of Mercury Tengda. The light is responsible for telling you "who is running now" and the background tells you "how much you have run".

There is also a kind of crazy flash that needs to be recognized separately: If a certain light flashes and stops regularly at three or four in the morning, it's not a thief. It's probably the NAS or surveillance system doing planned tasks. This is the point for backup and video archiving. My NAS runs incremental backups at three o'clock every night, and the light flashes on time for twenty minutes. Once I get used to it, I feel at ease - the light lights on time, indicating that the task has not failed. It's really a system-level problem. Don't rely on the light. Reading the log is more accurate than staring at the light.

Don’t panic if the light doesn’t come on. The five sources are arranged in this order.

The cable is plugged in, the device is on, but the light is not on. The most feared thing at this time is to directly sentence the router network port to death. First, rank them in five steps from low to high.

Step 1 has the highest hit rate. The four-core cable is an old stock cable from the 100M era. When plugged in to a Gigabit device, the link can be established and the light is on, but the speed is locked at 94M. ； To the extent that the light doesn't light up at all, it's probably because more than two cores of the crystal head are connected falsely or they're not pressed in at all. Anyone who has had a crystal head knows how useless this job is when your hands get wet. Crystal head wiring I scrapped six of that article before summing up the lessons. It would save me a lot of trouble to go back and read it when checking the threads. If the wire is running in the wall, the four-core and eight-core wires cannot be seen directly. Use a line tester to test it. Only four of the eight lights will light up and the answer will come out. The complete troubleshooting idea for the wire inside the wall is as follows What should I do if the network cable in the wall is broken? In that article, the method of finding breakpoints by dichotomy was tested and found to be useful.

Step 4 is a knowledge point that is easily missed: The lamp beads themselves can also break. The switching chip is working normally, the link is open, and the background status page is all normal, except for the lamp that is burned out. Don't worry about this. The lights are for people to see, not for the network. The reverse is also true - don't use the light as the only judge. If the light does not come on, check the link first. If there is no problem with the link, then doubt the light. , don’t reverse the order. If you really want to sentence a mouth to death, the standard is that the mouth on the background status page cannot be negotiated, not that the light does not turn on.

ending: Three sentences to take you out the door

The row of Mercury Tenda network port lights is condensed into three sentences. first sentence: If it is always on, it means communication. If it flashes quickly, it means there is data. If it is not on, check the line first. , four-state interpretation is a basic skill, and the lights flash wildly in the middle of the night to count whose mouth it is first. second sentence: If you have a two-color speed light, look at the color, green Gigabit and orange 100 Mbit. , the speed test card is 94 megabytes. First, squat down and look at the lights. A light saves a trip to the backstage. The third sentence: The light is an indicator, not a referee , whether the link is passable, how many megabytes to negotiate, and ultimately the status page and speed measurement will prevail. Lamp beads will be broken, and fake wires will deceive the lights. Only the numbers in the background do not lie.

A little tidbit at the end: Even the router system cannot control whether the network port light flashes or not. It is an instinctive reaction of the switching chip. So don't expect any firmware update to add a "network port light off" function for you. It's really noisy, and the light-shielding sticker will take care of it. ； I really think it's flashing suspiciously, so I'll first follow the instructions in this article to look at the light and catch the thief - after all, a free small light can do half of the traffic monitoring work, so it's useless if you don't use it.