Super classic! Recommended five Linux network monitoring tools (1)

BKJIA is just as important as monitoring network traffic and protecting data and computers. Understanding the most basic network fault diagnosis and troubleshooting skills helps you save time and costs. Each Linux release comes with a large number of command line tools to help you diagnose network problems. In addition, there are many open-source tools that can help you track annoying network problems.

BKJIA recommended topics: exhibition hall for Linux monitoring tools

In this article, I will recommend five command-line and open-source free Linux network monitoring tools to you to learn some simple commands in advance. When you need to use them to diagnose network problems, you will be more comfortable. I will use Ubuntu 10.04 as a test desktop platform, but these tools can work well in other Linux distributions or different versions.

Classic ping

If you do not want to use the Linux Command Line from the terminal, you can skip this section. In fact, the Linux Command Line is not so terrible, especially in terms of network problem diagnosis, the information displayed by most commands can help you determine what happened. Some command line tools may require root permissions or at least sudo commands.

Figure 1 ping

First, the ifconfig command. Enter this command at the command prompt to display all identifiable network device information. In the following example, you can see eth0, lo device, and wlan0, they correspond to the address 192.168.1.2 allocated by the wired Ethernet device), the loopback connection, and the wireless Ethernet device address 192.168.1.102). They also display the mac address HWaddr of the device and some network communication statistics, in case of network problems, you should first use this command to check whether the IP address is valid and network communication statistics or error messages.

Next, you should run the ping command to check whether your computer can communicate with the outside world. For example, ping a known external IP address such as 4.2.2.1) to quickly check whether your network connection is normal, it also shows the time used by the ping command. For common DSL-type network connections, the time is about 50 ms. The longer the time, the more unstable the network, if the ping packet is lost, the network problem is serious.

After using the ifconfig and ping commands, you should also use the route command. This command can display a string of IP addresses, including the target address and the gateway address that passes through the process, A flag column is also included. After the default gateway, the flag is displayed as G. You can ping the default gateway address to determine whether the connection between your computer and the gateway is smooth.