Basic network faults and troubleshooting

You may encounter many network failures in your daily life , However, every time something goes wrong, I don't know what to do , Just wait and wait , This is a big taboo for internal scrolling , So we can make the simplest investigation , And repair

When we encounter that there is no network link after we have connected to the network, we can try to test computers and routers / Switch link

1, Check Intranet

ipconfig

 

First, we can test the network connectivity ： 

Find the default gateway we ping it

ping  Your gateway  -t
##-t It's continuous ping It is a parameter , Usually used for real-time viewing , Press ctrl+c To terminate 

## If it's not connected here, we'll check the link between the computer and the router ##

Until now, what we have checked is as shown in the figure ：

If everything here is normal, our intranet will be very ok If you can't access the Internet, check the switches on the external network and router （ Without a switch, it's a bare cat ）

Generally, company switches are in weak current wells , The school computer room classroom is usually in the weak current box in the front or back

Network topology ：

notes ： The switch is recommended to find a professional network worker, otherwise the damage will be very serious

2, Check external network

win+r Input CMD Open Command Prompt Input ：

ping baidu.com
##ping Baidu's website to check the connection and disconnection of the network 

  What should I think of so much data ？

  Figure understanding （ Notebook as your current device ）：

Here some people will say ：“ I won't open any Internet software to have a look ？”

Oh, if so, it would be a big mistake  ！ As a person who comes to check information, he must be very diligent and voluminous , I won't make do with a lot of work .

1, If you open penguin's software when there is no Internet , Your login account may drop as ： some q music , Some news video

2, You can't see your current delay , I don't know whether the current network is suitable for me , For example, big data requires network delay , Back end requires network stability , Security testing requires the network to be relatively quiet （ Do security testing , It belongs to that kind of network security major, which requires relatively few devices in the network , Prevent accidental killing and interference with the results ）.

Then what should I do in this situation ？

1, Maybe the router is stuck （ The equipment tested is mi 3a  Installed opwrt Set for effect vlan And interference （ Isolation ）） unable ping The gateway may be open for isolation

2, The external network may be between the router and the switch. This should be carefully checked （ There is a problem with the bird food on the switch here ）

Finally, check the order of network problems ：

Software before hardware , Test more equipment , Don't do it blindly ;

Common sense of network security ： Remember not to divulge your IP Address 【ipv4,ipv6】