How to change the LINUX daemon and disable the port

Daemon knowledge linux has many daemon. most servers use daemon. At the same time, the Daemon completes many system tasks, such as job planning process crond and printing process lqd. Info & nbsp; | & nbsp;

========================================== Daemon knowledge ============================================
In linux, there are many daemon processes, and most servers use daemon. At the same time, the Daemon completes many system tasks, such as job planning process crond and printing process lqd.

A brief introduction to common daemon processes:
Kudzu (hardware detection) sshd (remote connection) inetd (network connection) ldap (Directory Access Protocol)

Linux running level:
The most commonly used is 3, 5.

Run level 0: it is used for shutdown. when it is started, it will be used for shutdown.
Run level 1: In Single user mode, only the root account is allowed to log on, mainly for system maintenance.
Run level 2: enables all users to log on, but does not enable NFS working, that is, there is no network function
Run level 3: enables all users to log on and have complete functions. It contains functions not available in run level 2, but is in text mode after startup.
Run level 4: defined by the user, but it is identical to run level 3 by default,
Run level 5: Similar to run level 3, the only difference is that the graphic interface is used after the startup,
Run level 6: restart. Restart immediately after startup

Chkconfig changes the running level of the daemon:
You can use the MAN Chkconfig command to view help information.
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Use the Netstat command:
Netstat-tn view current open port
Netstat-tnl: port used to view the listener status

Use Lsof with netstat to check which program is started on the corresponding Port:
Lsof-I: 111 view the PID value and COMMAND of the program Port 111
Kill 9441 close the port with PID 9441

Ntsysv graphical tool to disable unwanted services