NIS
Requirment package : ypbind
Ypserv
Yp-tools
portmap
Configuration File : /etc/yp.conf
Service start: service portmap start
chkconfig portmap on
ypserv start
service ypbind start
service yppasswdd start
service ypxfrd start
hkconfig ypserv on
chkconfig ypbind on
chkconfig yppasswdd on
chkconfig ypxfrd on
Make sure the portmap service is running:
client# service portmap start
client# chkconfig portmap on
The /etc/hosts.allow file will need rules allowing access from localhost and the NIS master server.
Start ypbind service:
client# service ypbind start
client# chkconfig ypbind on
NFS
Requirment Package: nfs-utils-lib
Nfsiutils-lib-devel
Nfs-utils
Service start : nfs
Portmap
Chkconfig nfs on
Configuration file: /etc/exports
Port no. portmap (111)
Nfs (2049)
DHCP
Requirement package: dhcp
Configuration file : /etc/dhcpd.conf
Service start: dhcpd start
Chkconfig dhcpd on
Port no: server side67, client side 68
SAMBA
Requirement Package: samba-common
Samba-client
Samba-swat
Configuration file : /etc/samba/smb.conf
Service : smb
Port no. 445
FTP
Requirement Package: vsftpd
Service : vsftpd
Configuration file: /etc/vsftpd/vsftpd.conf
Port no. 21
DNS
Requirement package : bind
Bind-utils
Bind-chroot
Caching-nameserver
Configuration file : named.conf
Port no: 53
Service : named
MAIL SERVER
Requirment Package: sendmail
Sendmail-cf
Sendmail-doc
Configuration file: /etc/mail/sendmail.mc
/etc/mail/sendmail.cf
cp /etc/mail/sendmail.cf /etc/mail/sendmail.cf.original
cp /etc/mail/sendmail.mc /etc/mail/sendmail.mc.original
Service : sendmail
Port no: smtp 25
Pop3 110 udp,tcp
Pop2 109
SQUID PROXY SERVER
Requirment Package: squid
Configuration file: /etc/squid.conf
Service start: squid
Port no: 3128
APACHE SERVER
Requirment Package: httpd
Configuration file: /etc/httpd.conf
Service start: httpd
Port no: 8080
Telnet port No. 23
Tftp 69
kerberos 88/tcp krb5 kerberos-sec #Kerberos
kerberos 88/udp krb5 kerberos-sec #Kerberos
nntp 119/tcp usenet #Network News Transfer Protocol
imap 143/tcp imap4 #Internet Message Access Protocol
snmp 161/udp #SNMP
bgp 179/tcp #Border Gateway Protocol
ldap 389/tcp #Lightweight Directory Access Protocol
login 513/tcp #Remote Login
printer 515/tcp spooler
router 520/udp route routed
phone 1167/udp #Conference calling
wins 1512/tcp #Microsoft Windows Internet Name Service
wins 1512/udp #Microsoft Windows Internet Name Service
l2tp 1701/udp #Layer Two Tunneling Protocol
pptp 1723/tcp #Point-to-point tunnelling protocol
radius 1812/udp #RADIUS authentication protocol
radacct 1813/udp #RADIUS accounting protocol
nfsd 2049/udp nfs #NFS server
man 9535/tcp #Remote Man Server
time 37/tcp timserver
rlp 39/udp resource #Resource Location Protocol
nameserver 42/tcp name #Host Name Server
nicname 43/tcp whois
http 80/tcp www www-http #World Wide Web
ntp 123/udp #Network Time Protocol
ssh 22
smtp 25
tftp 69
gopher 70
http 80
imap 143 udp,tcp
snmp 161 udp,tcp
Linux use three important file
1. /etc/grub.conf Grub information file The configuration file (/boot/grub/grub.conf), which is used to create the list of operating systems to boot in GRUB's menu interface, essentially allows the user to select a pre-set group of commands to execute.
2. /etc/fstab File system Information fileThe fstab (/etc/fstab) (or file systems table) file is a system configuration file commonly found on Unix systems. The fstab file typically lists all available disks and disk partitions, and indicates how they are to be initialized or otherwise integrated into the overall system's file system. fstab is still used for basic system configuration, notably of a system's main hard drive and startup file system, but for other uses has been superseded in recent years by automatic mounting. The fstab file is most commonly used by the mount command, which reads the fstab file to determine which options should be used when mounting the specified device. It is the duty of the system administrator to properly create and maintain this file. 
3. /etc/inittab Initialization fileThe inittab file displays and describes the five runlevels. It describes which processes are started at bootup and during normal operation.
Table 3-2. Subdirectories of the root directory
| Directory | Content |
| /bin | Common programs, shared by the system, the system administrator and the users. |
| /boot | The startup files and the kernel, vmlinuz. In some recent distributions also grub data. Grub is the GRand Unified Boot loader and is an attempt to get rid of the many different boot-loaders we know today. |
| /dev | Contains references to all the CPU peripheral hardware, which are represented as files with special properties. |
| /etc | Most important system configuration files are in /etc, this directory contains data similar to those in the Control Panel in Windows |
| /home | Home directories of the common users. |
| /initrd | (on some distributions) Information for booting. Do not remove! |
| /lib | Library files, includes files for all kinds of programs needed by the system and the users. |
| /lost+found | Every partition has a lost+found in its upper directory. Files that were saved during failures are here. |
| /misc | For miscellaneous purposes. |
| /mnt | Standard mount point for external file systems, e.g. a CD-ROM or a digital camera. |
| /net | Standard mount point for entire remote file systems |
| /opt | Typically contains extra and third party software. |
| /proc | A virtual file system containing information about system resources. More information about the meaning of the files in proc is obtained by entering the command man proc in a terminal window. The file proc.txt discusses the virtual file system in detail. |
| /root | The administrative user's home directory. Mind the difference between /, the root directory and /root, the home directory of the root user. |
| /sbin | Programs for use by the system and the system administrator. |
| /tmp | Temporary space for use by the system, cleaned upon reboot, so don't use this for saving any work! |
| /usr | Programs, libraries, documentation etc. for all user-related programs. |
| /var | Storage for all variable files and temporary files created by users, such as log files, the mail queue, the print spooler area, space for temporary storage of files downloaded from the Internet, or to keep an image of a CD before burning it. |
How can you find out which partition a directory is on? Using the df command with a dot (.) as an option shows the partition the current directory belongs to, and informs about the amount of space used on this partition:
|
sandra:/lib> df -h . Filesystem Size Used Avail Use% Mounted on /dev/hda7 980M 163M 767M 18% / |
|
3.1.3.1. Visual
For convenience, the Linux file system is usually thought of in a tree structure. On a standard Linux system you will find the layout generally follows the scheme presented below.
Figure 3-1. Linux file system layout This is a layout from a RedHat system. Depending on the system admin, the operating system and the mission of the UNIX machine, the structure may vary, and directories may be left out or added at will. The names are not even required; they are only a convention.
The tree of the file system starts at the trunk or slash, indicated by a forward slash (/). This directory, containing all underlying directories and files, is also called theroot directory or "the root" of the file system.
Run evel "3" will boot to text or console mode and "5" will boot to the graphical login mode ( "4" for slackware)
| Runlevel | Scripts Directory
(Red Hat/Fedora Core) | State |
| 0 | /etc/rc.d/rc0.d/ | shutdown/halt system |
| 1 | /etc/rc.d/rc1.d/ | Single user mode |
| 2 | /etc/rc.d/rc2.d/ | Multiuser with no network services exported |
| 3 | /etc/rc.d/rc3.d/ | Default text/console only start. Full multiuser |
| 4 | /etc/rc.d/rc4.d/ | Reserved for local use. Also X-windows (Slackware/BSD) |
| 5 | /etc/rc.d/rc5.d/ | XDM X-windows GUI mode (Redhat/System V) |
| 6 | /etc/rc.d/rc6.d/ | Reboot |
| s or S | | Single user/Maintenance mode (Slackware) |
| M | | Multiuser mode (Slackware) |
| he Linux Init Processes: |
| | | | |
The init process is the last step in the boot procedure and identified by process id "1". Init is responsible for starting system processes as defined in the /etc/inittab file. Init typically will start multiple instances of "getty" which waits for console logins which spawn one's user shell process. Upon shutdown, init controls the sequence and processes for shutdown. The init process is never shut down. It is a user process and not a kernel system process although it does run as root.
System Processes:
| Process ID | Description |
| 0 | The Scheduler |
| 1 | The init process |
| 2 | kflushd |
| 3 | kupdate |
| 4 | kpiod |
| 5 | kswapd |
| 6 | mdrecoveryd |
Init config file (Red Hat 7.3-9.0, Fedora Core 1-3): /etc/inittab
