Network Communication commands (relatively simple): 1. writeusrbinwritewrite [user name] is used to send information to the user, provided that the user has logged on to the server host, otherwise, therefore, write is a real-time communication tool
Network Communication commands (relatively simple ):
1. write/usr/bin/write
Write [user name]
Used to send information to a user, provided that the user has logged on to the server host
Otherwise, there is no way to leave a message for him. therefore, write is a real-time communication tool.
End the communication with Ctrl + D
E.g. write guest
2. wall [write all]/usr/bin/wall
Used to broadcast information to all users
Wall [message] [file name]
3. ping/usr/sbin/ping can only be executed by the root user.
Test network connectivity
Ping [option] IP address
Unlike Windows, you must press ctrl + c to stop running.
-C [count]: pingc stops running.
Ping-c 4 192.168.9.5: serves the same purpose as Windows.
-S [size]: change the package size, but there is a certain size limit
Ping-s 6000 192.168.1.1
Appendix: how to troubleshoot network faults in Linux
1) ping the host of the other party. if the host can be pinged, the network is normal.
2) you cannot ping the local IP address.
If the ping is successful, the TCP/IP protocol is correct.
3) the local IP address cannot be pinged. ping 127.0.0.1 and ping back the IP address.
If the ping is successful, it indicates that the TCP/IP protocol is not installed properly. if the TCP/IP protocol is installed, the IP address can be pinged even if there is no Nic.
In addition, even if a host is pinged but cannot be pinged, the network may not be faulty. in many cases, this situation may occur and you will learn it carefully later.
4. ifconfig/usr/bin/ifconfig
Used to view Nic information
The-a option is added by default in Linux, but in UNIX systems, the "-a" option must be added.
E.g. ifconfig
Ifconfig eth0 // view only the physical Nic
Ifconfig ech0 192.168.1.104 // Set the IP address ~, Only temporarily effective
Linux rules: to change the settings, you must write the configuration file