Understand the Ping command in one article: the "Swiss Army Knife" of the Internet world, allowing you to control it easily!

In our daily digital life, network connections are like invisible cables that silently connect us to information sources around the world. In this digital world, the Ping command is like a magic wand that can help us explore the mysteries of the network. This article will unveil the mystery of the Ping command and let you easily master this network tool.

What is Ping?

Ping, derived from the English "Packet Internet Groper", is a network tool used to test whether two computers can communicate. In layman's terms, when you use the Ping command, the network will respond to you: "Yes, I'm here!" or silently respond.

How to use Ping?

To use the Ping command, first open your command prompt (Windows users press Win + R, enter cmd and press Enter; Mac users open the terminal). Then, enter in the command line:

 ping [目标地址]

For example, you can try pinging Baidu:

 ping baidu.com

The output result is shown in Figure 1

Figure 1

Interpreting Ping results:

The result of the Ping command is actually the network response speed. The following is an explanation of some key information:

• Time: Usually displayed in milliseconds (ms), this represents the time it takes for information to be sent from your computer to the destination computer and back. The lower the latency, the faster the network.
• TTL (Time To Live): is an important concept in computer networks. It indicates the maximum time a data packet can exist or be transmitted on the network. The main function of TTL is to prevent data packets from circulating infinitely in the network. It can also be used to measure the transmission time of data packets in the network.
• Packet Loss: If you see something like "0% loss", that's good, meaning the information is arriving safely. However, if there is packet loss, it may mean that there is a problem with the network.

Advanced usage of Ping command

Specify the number of times: Sometimes you don't want to ping endlessly, you can add the -n parameter to specify the number of times to ping. For example:

 ping -n 5 baidu.com

Ping interval: The -i parameter can be used to set the Ping interval in seconds. For example:

 ping -i 2 baidu.com

The default result returned by the ping command is shown in Figure 2:

Figure 2

The ping command lacks an important indicator, the timestamp, by default. The timestamp is very important when troubleshooting. Fortunately, the pipe character can be used to add a timestamp to the ping command.

 ping [目标地址] | awk '{print strftime("%Y-%m-%d %H:%M:%S"), $0; fflush();}'

This command uses two common Unix/Linux commands, ping and awk, and combines them with the strftime function to add a timestamp to the ping command output. Let me explain the meaning of each part step by step:

(1) ping [destination address]: This part is the most basic ping command, which is used to test the network connection with the specified destination address.

(2) |: This is the pipe character, which passes the output of the ping command to the next command, which is awk.

(3) awk '{print strftime("%Y-%m-%d %H:%M:%S"), $0; fflush();}': This is the awk command part, which processes the output of ping.

• '{print strftime("%Y-%m-%d %H:%M:%S"), $0; fflush();}': This is an awk block that processes each line of output.
• strftime("%Y-%m-%d %H:%M:%S"): This is a function in awk that is used to format the current time into a specified format, here year-month-day hour:minute:second.
• $0: This represents the entire input line. The print statement in awk prints the formatted timestamp and the entire input line.
• fflush();: This is a command to force the buffer to be flushed, ensuring that each ping output is displayed in time. Therefore, the entire command is to pass the output of the ping command to awk through a pipe, and then awk adds a timestamp to the front of each line, and finally prints the results with the timestamp. As shown in Figure 3

Figure 3

Application Scenarios of the Ping Command

• Troubleshooting: When you visit a website slowly, Ping can help you find out whether it is a network problem or a website problem.
• Network monitoring: System administrators often use Ping to monitor the availability of network devices.
• Security detection: Some network attacks may cause network instability. Ping can be used to preliminarily determine whether the network is under attack.

Conclusion

Although the Ping command seems simple, it plays an irreplaceable role in the network world. By learning and using Ping, you can better understand the stability of network connections, solve network problems, and swim in the digital ocean. Let's hold this network probe tightly and explore a wider network world!