#RUN LEVELS#

 RUN LEVELS ___________________________________________________________

                           RUN levels are the levels or stages in the Linux that are used to do the 

                           Different kinds of works of particular levels.   

1__There are 7 run levels in the Linux .They have there own different works

The each run level start from the [init]  run level is the initialization of a task to do.

Init = initialization.

The 7 run levels are

                                    Run level.                  Works.                                                            Level no.

                                    Init 0                           shutdown system.                                        Level 0

                                    Init 1                           troubleshooting                                            level 1

                                    Init 2                           multitasking, multiuser,  no networking    level 2

                                    Init 3                           for command mode                                      level 3

                                    Init 4                           no use                                                            level 4

                                    Init 5                           GUI mode                                                      level 5                                                            init 6                           restart system                                                level 6

These are the some particular levels that  do there particular works and also they are not commands.ss                    

DIRECTORY STRUCTURE OF LINUX :-

·         /root :- Administrative user DIR when login through root user, the root users home directory. Some system related files or we can store data in this directory

·         /home :- Local user’s home DIR. Anyone can store data in this directory. We can use this directory as D:/

·         /etc :- All configuration files in this Dir file. System installation script, server configuration tools or all schedules in this directory.

·         /bin :- Local users and administrative user executable binary file.

·         /sbin :-only administrative users execute these binary files.

·         /var :- Printer  spooler. Log sheets (log creators)

·         /boot :- booting files, kernel images ( virtual kernel & permanent kernel). Grub boot loader file.

·         /proc :- information about hardware, device, CPU information, memory information.

·         /mnt :- temporary mount directory like CD-ROM, floppy.

·         /usr :- rpm – Linux. Red hat packet manager.

·         /tpm :- temporary files for 10 days.

·         /tft boot :- trival file transfer protocol

·         /dev :- it contains device drivers  files.

·         /opt :- it is for third party software.

·         /lost+found:-it acts as a recycle bin in the command mode and as a trash in The GUI mode.

·         /lib:- it contains the library a file of all software’s to open all software’s request is first gone to the /lib for open the application.

·          /temp:- it contains the all temporary files.

                          

DHCP SERVER CONFIGURATION

Dhcp server is used for to give automatic ip addresses in the network in which it is used………………

1_ automatic ip addressing.

2_ port no is {68}.

3_ main configuration file or the dhcp server is  {dhcpd.conf}  /////    {# vi /etc/dhcpd.conf}

4_ domain/service of dhcp to start is

               

        # service network restart ____________ to restart the service for the network.

        # service dhcpd restart _______________ to start the service of the dhcp server.

5_ installation packages  rpm`s____ are given in the installation { RHEL} DVD In the {

6_ to install the packages of the dhcp go to the directory in the dvd in which the rpm packages are then ..

        Run the command

        #rpm   -ivh  dhcp*    - - aid  - -  force _________ to install the packages from the dvd.

{redhat package }   {install vervosly}                              {forcefully}                  

    {manager}              {enhance}           

7_ to UPDATE the packages of the dhcp _________________”

        # rpm   -uvh   dhcp*    - -aid   - - force _____________ to update the packages  of dhcp.

                        {update}         

8_  to REMOVE the packages of the dhcp or any of the service___________________

        # rpm   -e  dhcp -3.0.5 _______ to erase the packages

                        {erase}

        { remember packages are to be erasing or remove one by one by full name of the packages}

                { but all packages are installed jointly in a single command }

9_ disable firewall ____________________# lokkit _________________________

SERVER   SIDE                                               

                Dhcp server has 6 packages install              

Dhcp server             10.0.0.2 Lokkit disable firewall

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        

#setup ________ to give the ip

# Service network restart __ network service         

# lokkit _disable firewall                                                                                                       

Then insert DVD  and mount with the /mnt                            

# mount /dev/cdrom  /mnt____ mount with .

#ls

# cd Server

# ls  dhcp* __ to check  the dhcp packages.

#rpm   -ivh dhcp* - - aid  - - force

   {4} packages for dhcp.

___ to install dhcp packages.

# rpm  -qa  | grep dhcp* to check if all install                  

This is the all main configuration for the dhcp server on the server side or on the client side

Now how to configure the main configuration file for the dhcp server.

That is             vi /etc/dhcpd.conf_________main configuration file for the dhcp server.

        But   __ we have to copy this file from the other place in the /etc directory because this                      this file is not present at there. So we have to copy that from

                # cp  /usr/share/doc/dhcp -3.0.5/dhcpd.conf.sample    /etc/dhcp.conf   _____to                                                                                                                             copy.

 CLIENT SIDE

                In dhcp client 2 packages are by default install

DHCP CLIENT

                                                                                                                                                       

     # service network restart

    # lokkit_____________

   #dhclient ______- request from client to