Command details for Linux network communication

Command--------------------------------------------------------------------------------------network communication: Write function: Send a message to a user (The other party must log in, should not be received) scene: 1: Now the Linux server has 2 users working: Root, Leyangjun 2:root in Beijing Leyangjun in Shanghai 3: Two people are simultaneously logged in the system work exchange similar to QQ, real-time communication root:w  Rite Leyangjun (Write command) This is my test,hello! (written content) Ctrl+d end input leyangjun:message from [email protected] .....  Information this is my test,hello!    This message is the root of the two: wall (all user) feature: Broadcast information to all users, everyone on the server can receive broadcast content example: Wall Leyangjun Hao man! Ctrl+d End Three: Ping test network connectivity Ping 192.168.11.1 and Windows is different, as long as you do not press CTRL + C it will not stop ping ping-c 3 192.168.11.1 means ping host 3 times introduction C number of times Ping is 64 bytes ping-s 65507 192.168.11.1 (ping packet max bytes is 65507 bytes) Experience Sharing: Note that sometimes you can ping the answer packet to prove that the network has no problem 1: First we have to look at the ICMP response speed,  Time Value 2: Observe the packet loss rate, 0% packet loss share: In doing a project test when met, 10 times there is one or two times data can not be entered into the database at that time we daoteng Daoteng finally changed the root cable problem to solve the bird, why? A: The low-end line tester can only test the network cable can be connected, a series of light is not a problem, but the loss rate is not measured. Sometimes there will be loss of packet rate: network cable in the warm summer in winter, there will be stretching, cable production process line cable contact will cause packet loss rate, including many times the network card failure will also cause packet loss rate. Be sure to check your cable, network equipment four: Ifconfig View the network settings information (view the IP address of the host)-a display all network card information eth0 is your actual network card information ifconfig eth0 corresponding IPAddress: Inet addr:192.168.1.55 change IP address: ifconfig eth0 192.168.9.56 (you will find that the next time you restart the original IP is not the IP you changed, because it did not write to the configuration desired file inside) 

Command details for Linux network communication