Overview of Linux Program Services

Program services are the services that your server will run, and be utilized. These are what makes your server a server generally, and what brings you clients. No matter whether your buyers be paying users (such as in an ISP), or they be donation customers (users that give little or no money towards your server), they are still crucial. They are the purpose that you want a server, so it is critical to feel of them. Linux delivers _Numerous_ services, right here are some of the more common solutions_

_ Shell Solutions (The Safe SHell (SSH), Telnet, Remote Shell, and so forth)_br__ Mail Services (POP3, SMTP)_br__ Web Solutions (Web Hosting)_br__ DNS Services (Domain Name Services)_br__ FTP Solutions_br__ Talk Solutions (through Talked, enables users logged in to chat with each and every other)_br__ Kerberos Services (secure authentication strategies)

Linux delivers many other solutions, of which will be described in detail later. Most of the services lie in the _etc_init.d directory, which is really a set of start off up scripts, but as most services are started at boot, so the _and so on_init.d directory would be a very good location to commence searching for solutions installed…..you can also attempt tel netting to recognized service ports, which are listed as follows_

Telnet_ 23

SMTP_ 25

HTTP_ 80

DNS_ 53

SSH_ 22

Speak_ 517

Kerberos_ 750

FTP_ 21

If you are operating the service, you will get a message that appears like_

_house_ares&gt telnet localhost.localdomain 22_br_Attempting…_br_Connected to localhost.localdomain._br_Escape character is ‘^]’._br_SSH-1.five-1.2.20

Then you are operating the service that is reported. Also, you can download the portscanner nmap from from insecure.org. It is available in RPM formats, as properly as .tar and .tgz formats. When installed, you can invoke it by utilizing the following syntax_

nmap localhost.localdomain_br_Nmap will then output all the open ports on your server. This is also good for scanning other servers on your network, to see what services they are running. If you see a service, such as Sendmail (SMTP service) operating, and you do not want it, I advocate removing it, via commenting out the lines in _and so forth_init.d_sendmail, or by just issuing the following command_

_and so on_init.d_sendmail cease

Then un-installing it, with the package manager for your distribution (i.e. rpm for Red Hat Linux). For instance, to un-set up a rpm package, use the following command_

rpm -e packagename

To see a list of all rpm packages, use the following command_

rpm -qa _ much more

This will send the output to the a lot more command, as we have covered earlier. If a package offers you a dependency error, you will need to un-set up the dependency very first, or you may possibly force the un-set up with the -f choice (_NOT_ advised). You can use the deselect system in Debian Linux to eliminate the unwanted package, just variety_


To bring the deselect menu up. This is far more user-friendly than the rpm utility, if you like interfaces that is. Now, we will move on to certain solutions, the 1st on the list is the apache internet server.