Why is the PC network port always disconnected, the computer network cable will always be disconnect

I'm also experiencing this symptom. I asked the telecom repairman and he said the reason was:

Now summer is the peak of electricity consumption, especially at night. The voltage of the cat (modem) is too low, causing the connection to drop, which is unavoidable, and it should not be possible to play during the day. (I'm helpless too!) Do you have the following two symptoms?

The computer tray says: Local Connection.

The network cable is not plugged in. In addition, there are 4 lamps on the modem (cat) power

linkdata

Ethernet is the first of these four lights (one).

Steady on: When the second one drops the line, it stays on when it can't be flashed.

The third one should be foil.

Sometimes it doesn't light up.

The fourth one should be severant.

b) The modem (cat) light suddenly jumps off and only the first and second lights stay on, and the other two flash. You can find it if you play a game for a few minutes, there should be a sale in the computer city (or to the electronic components sales store), because the cat has a voltage regulator module inside, so you have to buy a switching voltage regulator power supply between, if you buy 9V directly unstable, because the voltage drop of the voltage regulator module is. The output current is slightly greater than yours.

The current of the original cat power supply (generally greater than 800mA), so that the switching regulated power supply can have a stable output and is not easy to burn out. If my answer is helpful to you, I hope it will be accepted, thank you.

You can do the following tests:

1. Use a line tester to detect whether there is a problem with the network cable, and the network cable 1 2 and 3 lines will be broken and the local connection X will occur.

2. The crystal head of the network cable is aging, and the metal piece cannot contact the metal connector of the network card.

3. The network cable is broken, that is, the middle is cut.

4. If the network cable is too long or there is interference, the signal is seriously attenuated, and a relay device, such as a router, can be added.

Very typical ARP conflict (it is not excluded that it is a deliberate ARP attack) ARP is simply the relationship between IP and MAC address MAC address is the unique address of the manufacturer to the production of Internet equipment (the MAC address of any Internet device is unique) Intranet ARP conflict This is also a common intermittent network disconnection fault is caused by the repeated use of an IP of the Internet equipment under the LAN The solution is to use a network cable to connect the PC and the route (the route needs to be powered It cannot be plugged into the WAN port) Enter the routing address and password in the address bar of the web page (the factory default value is on the back of the route), as shown in the figure.

This is an example of a Werman route

After entering, find the DHCP setting and separate a certain address segment as the column is to.

Concentrate; It is very common for the IP address obtained by automatically obtaining the IP address to be slow or even sometimes disconnected.

It's very likely that your problem is this fault, and if it still doesn't work, it's a line fault or a device fault.

The line fault and equipment failure I am talking about are divided into intranet and extranet, and the internal and external network is generally speaking, it is your home line and equipment and the operator's line and equipment, and the way to troubleshoot the problem is to plug the network cable out of the modem into the computer, connect it with a broadband connection, and use the command to measure the network failure Click Start Run -Input- ping + space + external network operator address + space + "-t" (for example, ping is ping Heilongjiang Telecom server address as shown in the figure.)

If there is an interruption, the network is disconnected, if it is not the failure of the network cable connecting the modem and modem connection PC of your home, it is the fault of the external network, you can call the customer service ** to the fault repair and wait for the maintenance of the technician (Unicom customer service 10010, Telecom 10000).

If you don't understand anything that is helpful to you, please ask me.

In addition, Shengfeng teaches you how to make the computer achieve the fastest network speed under the condition of fixed bandwidth, fixed network cable (wifi signal), and fixed Internet equipment, that is, the setting of the route, ARP binding, and DNS resolution, first of all, ARP binding, bind the IP (intranet) to the MAC address of the PC, and use it Simply put, it is to set up an IP that belongs only to your own IP for your computer under the local area network, as shown in the figure above, after entering the route, find the ARP binding in the ARP option Fill in the IP and local MAC address to save the settings, and the MAC address query method is as follows: Start-Run-Enter cmdEnter-Enter ipconfig+space+allEnterThe content of the physical address item is the MAC address of this computer.

DNS resolution is to let the router automatically connect to the broadband and give it the nearest or fastest DNS

The method is still to set DNS in the route, which is the same as filling in the DNS in the PC, because the router brand is different, the setting page is also different, and the map cannot be attached.

1) If it is a problem with the broadband itself, first directly connect the broadband network cable to test, if it is a broadband problem, contact the broadband customer service to solve it.

2) If it's a problem with the router, if it can be used originally, it can't be used for the time being, my own practice is to disconnect the power of the router and plug it in, and I'll take a look. In there is a factory reset, from the new strict according to the manual settings can be used, I don't understand, it is not recommended to set it at will (this is under the premise of the correct physical connection, sometimes the router is slow or failed to find the IP address, not that the router is broken).

If it can't be solved all the time, it is recommended to call the customer service of the router, they have **** guidance, I encounter a problem that I can't solve by myself, it is very useful to consult the advice they gave, and they will give the correct advice for your settings or operations.

3) If you turn off the wireless switch, turn it on, if it is a wireless connection with software, it is normal for the software to be difficult to use and often have problems, there is no better way, use a router. In addition, it is caused by the network card driver is not or is not suitable, and whether there is a problem with the network cable interface or network cable.

4) If it is caused by a system problem, it is recommended to restore the system or reinstall it.

5) If you have any questions, please ask me.

In this case, it may be that the network operator has merged the network connection into a local connection, or it may be because the computer has misrecognized the state of the network connection.

There are several solutions to this problem:

Consult your network provider (which is usually the case in public networks, so you can check with your hotel manager, park management, etc.) to see if the network is already included in your local connection. Because local connections can provide network-critical data such as IP addresses and MAC addresses, some network providers include network connections in local connections.

Check to see if your computer is connected to the network through third-party software. There is currently some software that is able to perform assisted dialing when the local connection is normal, resulting in a normal network connection and the system still considers the broadband connection to be unconnected. Therefore, try to use software that can report network conditions to the system to prevent such errors from occurring.

Check that your computer's wireless card is enabled and connected to an active wireless network. Because some computers do not recognize the wireless network card normally, the wireless network card has been connected to the network and the system still thinks that the broadband connection is not connected. If this happens, you can try to reinstall the NIC driver.

Dear, hello, the computer is poisoned, reinstall the system!

There is a problem with your computer system, it is recommended that you reinstall the system!

There are 2 possibilities for this: 1If the line is not good, call your network operator and ask them to check the line or your adsl is unstableIt is possible that the network card is not good, and there is a problem with the driver, and this solution can be replaced by a notebook or other desktop to try it.

In short, try to use the elimination method in two aspects to find the right cause and solve the problem.