Linux system service startup and the prohibition and the corresponding port number

/Etc/services view system default services and ports corresponding to the individual DAEMONS (services) of startup and shutdown scripts are placed in/etc/init.d/, but REDHAT system is put into the/etc/rc.d/init.d inside, as regards the control parameter file superdaemon is placed in/etc/xinetd.d inside.

Standalone (independent startup) and superdaemon (super service) standalone as the name implies, standalone is directly perform the service scan line stalls and let the executable directly loaded into memory, operation, this way to start this service can be made with a quick response. Generally speaking, this kind of services launch scrip will place the/etc/init.d/directory underneath this, so you can often use: [/etc/init.d/sshdrestart] like to start this service; With a super service superdaemon as mains, to manage some network services in the use of the inside CENTOS4.3 is xinetd this superdaemon, this way start network services while in response speed be slow, however, can provide some additional through superdaemon control, for example control when to start, when you can be online, the IP can even come in, whether to allow simultaneous online and so on. Usually profile in/etc/xinetd.d/, but needs to be set is finished to [/etc/init.d/xinetdrestart] to start again. If you want the system to switch off the PORT25, above the simplest approach is to first identify the PORT25 's startup process. # Netstat-tnlp TCP00127.0.0.1: 6310.0.0.0: * listen1171/cupsd//22, the port is opened by the program cupsd. If the program is not visible, use the CUPSD nmaplocalhost to view native ports, will show port and the corresponding procedures. # Whichcupsd/usr/sbin/cupsd//identify cupsd program location. If not found, WHICH is used to LOCATE with the formal notation to find this directive. # Locatecupsd | grep '/cupsd $ '/usr/sbin/ssd use RPM to treatment: # rpm-qf/usr/sbin/cupsd cups-1.1.17-13//identify the program name # rpm-qccups | grepinit/etc/rc.d/init.d/cups//identify program startup. #/Etc/rc.d/init.d/cupsstop//stop program.