Top 10 network commands under Linux

In order to better use Linux, we must know some necessary network commands of Linux and better understand the performance of Linux.

1. curl

The curl command is a file transfer tool that uses URL rules to work under the command line. It supports file upload and download, so it is a comprehensive transmission tool. However, according to tradition, curl is called a download tool. As a powerful tool, curl supports many protocols including HTTP, HTTPS, ftp, etc. It also supports features such as POST, cookies, authentication, downloading partial files from specified offsets, user agent strings, speed limits, file sizes, progress bars, etc. . To automate web page processing and data retrieval, curl can help.

The curl command can be used to perform operations such as downloading, sending various HTTP requests, and specifying HTTP headers. If the system does not have curl, you can use yum install curl to install it, or you can download and install it. curl outputs the downloaded file to stdout and outputs the progress information to stderr. Use the --silent
option to not display progress information.

curl URL --silent

2. wget

The wget command is used to download files from the specified URL. wget is very stable, and it has strong adaptability in situations with very narrow bandwidth and unstable networks. If the download fails due to network reasons, wget will continue to try until the entire file is downloaded. If the server interrupts the download process, it will contact the server again and continue downloading from where it stopped. This is useful for downloading large files from servers that have limited connection times.

3. ping

The ping command is used to test the network connectivity between hosts. Executing the ping command will use the ICMP transport protocol to send a message requesting a response. If there is no problem with the network function of the remote host, it will respond to the message, thus knowing that the host is operating normally.

4. traceroute

The traceroute command is used to trace the entire path of data packets when they are transmitted on the network. The default packet size sent is 40 byte.

Through traceroute we can know the path that information takes from your computer to the host at the other end of the Internet. Of course, the path a data packet takes from the same starting point (source) to the same destination (destination) may be different every time, but basically the route taken is the same most of the time.

traceroute measures how long it takes by sending small packets to the destination device until it returns. Each device on a path is traceroute tested three times. The output includes the time (ms) of each test and the name of the device (if any) and its IP address.

5. The host

host command is a commonly used analysis domain name query tool and can be used to test whether the domain name system is working properly.

6. Whois

is used to find and display information related to the specified user account and domain name, including domain name registration time, owner, email, etc. Similar commands : tracepath, host, nslookup, who, pwd.

7. ifplugstatus

The ifplugstatus command can tell you whether there is a network cable plugged into the network interface. This command is not pre-installed in Ubuntu. Use the following command to install it

sudo apt-get install ifplugd

This command can view the status of all network interfaces or the status of a specified network interface

8. ifconfig

The ifconfig command is used to configure and display the network parameters of the network interface in the Linux kernel. The network card information configured with the ifconfig command will no longer exist after the network card is restarted and the machine is restarted. If you want to store the above configuration information in your computer forever, you need to modify the configuration file of the network card.

9. ifdown/ifup

The ifdown command is used to disable the specified network interface. The ifup command is used to start the specified network interface;

10. netstat

The netstat command is used to print the status information of the network system in Linux, allowing you to know the network status of the entire Linux system.