China DOS Union

1、Typical Order of Detecting Network Failures via Ping

Under normal circumstances, when we use the Ping command to find the problem or test the network operation, we need to use many Ping commands. If all run correctly, we can be confident that the basic connectivity and configuration parameters are fine; if some Ping commands have operation failures, it can also indicate where to find the problem. The following gives a typical detection order and corresponding possible failures:

- ping 127.0.0.1
This Ping command is sent to the IP software of the local computer, and this command never exits this computer. If it doesn't do this, it means there are some basic problems with the installation or operation of TCP/IP.

- ping local IP
This command is sent to the IP address configured for our computer. Our computer should always respond to this Ping command. If not, it means there is a problem with local configuration or installation. When this problem occurs, LAN users should disconnect the network cable and then resend this command. If this command is correct after the network cable is disconnected, it means another computer may have the same IP address configured.

- ping other IPs in the LAN
This command should leave our computer, pass through the network card and network cable to reach other computers, and then return. Receiving a ping response indicates that the network card and carrier in the local network are running correctly. But if 0 ping responses are received, it means the subnet mask (the code that separates the network part and the host part of the IP address when subnetting) is incorrect, or the network card configuration is incorrect, or there is a problem with the cable system.

- ping gateway IP
If this command responds correctly, it means the gateway router in the LAN is running and can respond.

- ping remote IP
If 4 responses are received, it means the default gateway is successfully used. For dial-up users, it means they can successfully access the Internet (but it doesn't rule out problems with the ISP's DNS).

- ping localhost
localhost is a network reserved name of the operating system, which is an alias of 127.0.0.1. Every computer should be able to convert this name to this address. If it doesn't do this, it means there is a problem in the host file (/Windows/host).

- ping www.xxx.com (such as www.yesky.com Yesky.com)
Ping the address of this domain name, usually through the DNS server. If there is a failure here, it means the IP address configuration of the DNS server is incorrect or the DNS server is faulty (for dial-up users, some ISPs no longer need to set the DNS server). By the way: we can also use this command to realize the function of converting domain names to IP addresses.

If all the above-listed Ping commands can run normally, then we can basically be at ease about the functions of local and remote communication of our computer. However, the success of these commands does not mean that all our network configurations are fine. For example, some subnet mask errors may not be detected by these methods.

Learning and learning~~ Thank you~~

Learning

It is quite useful for checking network faults