how to check network status in linux

1. Use the ip command to view basic network information. Enter ip a to obtain the local IP, subnet mask, MAC address, etc., and use ip route to view the routing table. 2. Test network connectivity by ping, such as ping google.com or ping IP address, no response may involve DNS, network interruption or ICMP blocking issues. 3. Use ss or netstat to view the connection status, such as ss -tuln | grep port number, to confirm whether the service listens for the correct port. 4. Using nmcli is suitable for desktop users to view network management status, such as nmcli dev show that can display the connection status and IP acquisition method. The above methods can be selected and used according to different scenarios. Mastering IP and ping is the basic requirement, while SS, Netstat and NMCli depends on the environment.

Want to know how to check network status in Linux? In fact, there are quite a lot of methods, and most tools are installed by default. The following common methods can basically meet daily inspection needs.

Use ip command to see basic information

This command now almost replaces the old ifconfig and is recommended to use it first.
enter:

 ip a

You can see basic information such as the local IP address, subnet mask, and MAC address.
If you want to see the routing table, you can use:

 ip route

If you just want to confirm whether a network card is working properly or whether the IP is misaligned, use this command the fastest.

Test network connectivity with ping

If you just want to see if you can access the Internet or whether a certain server is accessible, the easiest way is to ping the target address, such as:

 ping google.com

Or ping the IP directly:

 ping 8.8.8.8

If there is no response, it may be DNS problems, network blockage, or the other party blocks ICMP requests. At this time, you can try other methods to investigate further.

Use ss or netstat to view the connection status

These two commands are used to view the network connection, listening port and other information on the current system.
For example, if you want to know if there is a program listening on port 80, you can execute:

 ss -tuln | grep 80

Or use netstat (some systems are not installed by default, and the net-tools package may be required):

 netstat -tuln | grep 80

Output:

• t means TCP
• u means UDP
• l Only services that display listening status
• n Display address and port in digital form

If you find that a service should be running but does not appear here, it may be that the service is not started, or the configuration file is written in the wrong port.

Use nmcli to view network management status (suitable for desktop users)

If you are using a GNOME desktop environment, it is likely that NetworkManager is behind it to manage the network. You can try this now:

 nmcli

It will list the current connection status, IP acquisition method, device type, etc.
For example, if you want to see the details:

 nmcli dev show

This is useful when switching Wi-Fi on your laptop or troubleshooting the connection status, especially when there is a problem with the graphical interface settings.

Basically, these are the methods, just select different commands according to different scenarios. Like ip and ping are almost essential skills, while ss and nmcli will depend on your usage environment to determine whether you need to master it.

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