Conduct network physical examinations at home on a monthly, quarterly, half-year, and annual basis to uncover three hidden dangers that have been hidden for two years

Last month, the hard drive of his cousin's NAS died without warning. He went through the chat history to find the SMART screenshots from three years ago. He died on the spot. After reading what happened to him, I looked back at my home: optical modem has not been in the backend in four years. The configuration backup of the router was done the year it was replaced. The UPS has not been drilled for power outage since it was purchased. To put it bluntly, the network equipment at home is just like a car. It is not worth looking at if it is broken. It needs to be maintained regularly. Taking advantage of a weekend, I checked my home from beginning to end in four cycles: monthly, quarterly, half-yearly, and yearly. I found three hidden dangers that had been hidden for two years. This article will explain the judgment criteria and periodic table in one go.

Make it clear first: The physical examination is about thunder, not illness

Many people have no concept of "network physical examination" and think that normal Internet speed means good health. In fact, most of the faults in home networks do not occur suddenly, but are accumulated slowly.: The light attenuation drifts two to three dB a year, and when it drifts to around -28, it starts to drop out in the middle of the night. ； The capacitor ages a little every year and will crash in the summer after three years. ； If you don’t change your password for three years, Chongwang’s dictionary will have already reached its eighth round. By the time you really feel something is wrong, something has probably already happened.

There is only one idea for physical examination: Find out the trends that are “getting bad” before they are bad. . Therefore, the core action is not to cultivate, but to "leave bases and make comparisons." On the day of installation, what was the light attenuation, speed measurement, and equipment? Copy them all. ； If you look at it again after a while, it will be clear at a glance which direction the numbers are going. I wrote these numbers on a piece of paper and stuck it on the inside of the weak current box cover. Four years later, I still add notes to this piece of paper. It works better than any memo.

Two things I do every month that take less than ten minutes in total

The principle of monthly inspection is "no fuss", just look at it. The first thing is to log on to the router’s backend homepage and scan the fields on the running status page.: WAN port IP, running time, number of connected devices, memory usage . If the WAN port changes from the public network address to one starting with 100.64, it means that the operator has cut you into the large intranet, and the way home remotely is cut off on the spot. You would never know this unless you look at it. If the running time often returns to zero, it means that the machine is restarting repeatedly, and you need to check the power supply and heating direction.

The second thing is to pick a speed test during the evening rush hour (most typical around 9pm) and write down the numbers. There are particularities to posture when measuring speed: Plug in the network cable directly, turn off downloading and backup, and test again. I’ve written all the specific pitfalls in this article. . The evening peak speed test once a month is more convincing than any single speed test - my Gigabit speed was stable at around 940 last year, but fell to 880 during the same period this year. This slowly declining curve is the strongest evidence when you report to the operator for repairs.

Quarterly: Equipment roll call, I cleared out seventeen zombies

The highlight of the quarterly inspection is the equipment inventory. Open the router’s device list and read through them one by one.: Who is this station, who is that station. I have 62 devices in my home, I really can’t remember them without naming them. Don’t panic and block the device you don’t recognize. Click Three tips for recognizing people walk through: Look at the online time patterns, check the top six manufacturers of MAC, and eliminate them one by one. This time I cleared out two zombies during roll call.: There are more than a dozen disposable devices that have been eliminated long ago in the device list (a mobile phone that a relative came to visit and an old tablet that I replaced), and there is also a more hidden one - the static IP binding table. The HP printer sold in 2023 is still nailed to the device list. 192.168.31.15 superior. This kind of entry is harmless in itself, but when you manually assign this IP to a new device one day, a mysterious fault of "on and off" will occur, and you will not be able to figure it out after a long time of searching.

Do two small things when calling your name:: The first is to rename familiar devices and make notes ("living room TV" "parents' mobile phone") so that you can locate problems at a glance next time ； The second is to turn off the guest network - a relative left the guest WiFi on for half a month. This has happened to me more than once.

Once every six months: Firmware, backup, UPS discharge testing

This half-year period is a hands-on period, with three things. The first thing is the firmware. Router firmware policy I am in Automatically upgrade the article Wrote the conclusion: The stable version has automatic upgrade enabled. Don’t mess with the firmware of Optical Mode yourself, wait for the operator to push it. Just take a look at the version number every six months. Don’t be obsessive and feel uncomfortable if you don’t see the new version. I also checked the surveillance camera in the yard. The firmware has not been updated in three years. This kind of equipment should be stopped and replaced according to the old rules.: Change the password and don’t expose the port. Follow the checklist in the safety self-inspection section .

The second thing is configuration backup. Router background export config.bin , save one copy each on your computer and network disk. This file is dozens of KB and does not take up space if it is stored for ten years. However, if the main router is struck by lightning one day, the new machine can be restored to the same state in ten minutes - the broadband account, WiFi name and password, and static binding are all included. Backup paths and several pitfalls I’ve written it before, so I won’t repeat it. During my physical examination, I found that my backup was from two years ago. After importing the new one, the old one was not deleted.: Old backups are also assets, and the new configuration can be rolled back if there is a problem.

The third item is the UPS discharge test. This is the second hidden danger that I uncovered during this physical examination. I have two UPS at home, the one with NAS is 600VA. The year I bought it, the drill lasted 47 minutes. . This time, I unplugged the mains power and took another test. There were only 18 minutes left. The lead-acid battery had been used for three and a half years. It is normal for it to decay to this extent. However, 18 minutes is enough for "waiting for the NAS to shut down safely", but not enough for "waiting for me to get home and handle it manually". I bought a battery of the same specifications online for 115 yuan and replaced it myself, it only took five minutes. Another one with an optical modem router The small UPS is still on the four-hour block ,healthy. This test is really recommended: Batteries are consumables, and you never know how much power they have left.

once a year: Comparing the light attenuation base, finding out the 4 dB caused by the tie

The annual inspection is the most important thing, and the core is light decay. The received optical power measured by the master the year my optical modem was installed was -19.2dBm, which is copied on the sticker. Enter this time 192.168.2.1 Look - my home has changed the bridging. Before I can use the backend of optical modem, I need to assign a static IP to the computer first. I wrote an article about the ins and outs of this step. ——At first glance, -23.5. It has drifted 4 dB in four years and is still in the healthy zone (-8 to -27), but the trend is wrong.: At this rate, it will be patched in another four to five years. From -28 and above, there will be bit errors, interruptions, and disconnections in the middle of the night.

Follow the leather thread to find the reason, The third most common method of self-examination based on light failure ： Straighten the thread, wipe the head, and reinsert. Finally, the culprit was found in the weak current box - when I was sorting out the weak current box, I saw a clear picture. A tie tied the leather cord and the network cable together to form a small right angle. Optical fibers are afraid of bending but not pulling. If the bending radius is less than 5 cm, light will leak out. Cut the cable tie and coil it into a big circle, and then see that the light attenuation returns to -21.8, which is 2 dB back. The remaining attenuation is due to the natural aging of the cold connector and optical module. There is no other way to do it. Record it in the bottom number and continue to observe.

The rest of the annual inspection is all physical work: Dust off the weak current box (the dust collected over four years can cover the heat dissipation holes. Organize weak current box Do the same thing) ； Run the two NAS disks again SMART interpretation , focus on whether the remapping and RAW values ​​to be mapped are zero, and how much the number of power-on hours has increased. ； Take a look at the water level of the storage pool. If it exceeds 80%, you should plan to expand or clean it. Don’t wait until it is full before rushing around.

ending: Paste this periodic table on the weak current box, just follow it

Put four years of physical examination experience into a table, that’s all:

My sequence suggestion is also simple: For the first time, the "baseline" must be completed first - light attenuation, speed measurement, equipment inventory, and configuration backup. These four are the benchmarks for all subsequent comparisons. Without them, the physical examination becomes a blind test. Then just scroll through the periodic table. The most valuable of the three hidden dangers is the cable tie. It costs a pair of pliers to recover 2 dB. According to the speed of light attenuation and drift, it is equal to two years of life gained in vain. Network equipment, if you pay attention to it, it will save you ten points when it goes offline in the middle of the night.