INTRODUCTION OF LINUX

VENDOR	OPERATING SYSTEM
AT & Bell Labs	SYS-3 & SYS-5
SUN (Standard University Network)	SOLARIS
IBM ( International Business Machines Co-operation)	AIX
SG (Silicon Graphics)	IRIX
SCO (Santa Cruz Operation)	Sco-Unix
BSD (Berkelay Software Distribution)	Fee-BSD
HP (Hewlett Packard)	HP UX

Features of Linux Operating System:

Open Source:

∞   Free Software along with the source Code& Documentation.

Multi Tasking:

∞   Capable of running multiple applications and process at same time.

Multi User:

∞  Allows Multi User to login and use the resource at same time.

Portability:

∞   Can be installed on all Hardware Architecture

Scalablity:

∞   Same Operating System can be used on a desktop to a Uper Computer.

Reliability:

∞   Large Servers have been successfully being running without a single second of down timer.

Security:

In-built  Firewall and SE linux

FHS

FILE SYSTEM HIRERACHY STANDARD

STRUCTURE OF WINDOWS OPERTING SYSTEM:

BASIC COMMANDS

How to Open a Terminal?

Ø Right click open in Terminal

OR

Ø Click On application Terminal

 OR

Ø Click on Alt+F2

To increase Size of Terminal

Ø Ctrl+Shift ’+’

To decrease Size of Terminal

Ø Ctrl+ ’-’

To Get Ful Screen

Ø F11

#### HOW TO CHECK THE PRESENT WORKING LOCATION ####

# pwd

#### TO CHANGE THE LOCATION####

# cd

Ex:   cd  /

        Cd  /usr

        Cd  /var

     Cd desktop

#### TO CHECK THE CONTENTS OF DIRECTORY ####

# ls

#### TO CHECK THE PROPERTIES OF FILES & DIRECTORIES ####

# ll                                                                           

#### TO CHECK THE HIDDEN FILES & DIRECTORIES ####

# ls –a

#### TO CHECK THE INODE NUMBER OF FILES &DIRECTORIES ####

# ls –i

How to Create a File?

->To create the file

There are 3 commands:

Ø cat

Ø touch

Ø vi

CAT(concatenation):

Ø CAT command is a user to create a new text file

Ø To read the file and also append the file

Drawback:

Ø Cat command cannot be used to modify be the files and also to create multiple files.

     #cat > redhat (This is a root file)

     To Save: ctrl+d

TOUCH: Touch command is used to create multiple empty files.

DRAWBACKS:

         

Ø Touch command cannot be used to Write the file, Read the file and also modify the file

Ø Multiple # Touch

         

VI: Visual Interface

EDITOR:  Editor is used to editing adding, modifying and deleting text.

The different editors used

          *WINDOWS: Notepad

          *DOS: Edit

          *Linux/Unix

          -CLI BASED: EX, ED, VI

          -GUI BASED: Emacs,Gedit,nedit,nani,pico

Ø VI editor is a screen oriented text editor written by “Bill Joy” in 1976

Ø This is the most commonly used editor for editing files in Linux

VI EDITOR MODELS:

       

        VI editor has 3 models of operation

Ø Command mode

Ø Insert mode

Ø EX mode(extended mode)

Command Mode:

·        dd                - Delete’s a line

·        ndd              - Delete’s ‘N’ lines

·        yy                - Copies a line

·        nyy              - Copies ‘N’ lines

·        p                  - Put(pastes the deleted or copied text)

·        u                  -Undo(you can undo 1000times)

·        ctrl+r            -redo

·        G                 -Moves the cursor

·        /<word to final> -Finds a word(press for next)

INSERT MODE:

·        i                   -Inserts the texts at the current cursor

                       Position

·        I                   -Inserts the text in beginning of line

·        a                  -Adds the text after the current cursor

                       Position

·        A                  - Adds the text at the end of line

·        o                  -Inserts the text one line below current

                       Cursor position

·        O                 - Inserts the text one line above current

                            Cursor position

EXTENDED MODE:

·        q                  -Quit without saving

·        q!                 -Quit forcefully without saving

·        w                  -Write(save)

·        wq                -Save and Quit

·        wq!              -Save and Quit forcefully

·        se nu           -Set line numbers

·        se nenu        -Removes line numbers

### TO CREATE A FILE WITH DATA ####

# cat > (filename)

# cat > linux

This is linux

Press ctrl+D to save & quit the file

# cat linux (to read the file)

#### TO APPEND THE DATA WITHOUT OVERWRITING ####

# cat >> linux

Added data by root

Press ctrl+D to save & quit the file

# cat linux (read the file)

#### TO CREATE MULTIPLE FILES WITHOUT DATA ####

# Touch unix solaris redhat

# ls (to check)

#### TO CREATE A DIRECTORY ####

# mkdir <dir_name>

# mkdir zoom

# ls (to check)

# cd zoom (to enter into dir)

# cd (to come out)

#### TO CREATE A MULTIPLE DIRECTORIES ####

# mkdir zoom1 zoom2 zoom3 zoom4

# ls (to check)

#### TO CREATE A PARENT DIRECTORY ####

# mkdir –p world/asia/india/ap/hyd/dsnr/zoom

# ls –R world (to check)

#### NAVIGATION OF DIRECTORIES ####

# cd world/asia/india/ap/hyd/dsnr/zoom

# pwd (to check)

# cd .. (to come 1 step back)

# cd ../.. (to come 2 step back)

# cd ../../.. (to come 3 step back)

# cd – (to go at last working directory)

# cd (to go at user home directory)

# pwd (to check)

#### TO CHECK AND CHANGE THE DATE & TIME ####

# date (to check)

# date –s “wed Mar 19 12:00:00 IST 2014”

#### TO CHECK THE CALENDER ####

# cal (for current month & year)

# cal 2014 (for year)ot be

# cal 5 2014 (for particular month & year)

#### TO OPEN THE CALCULATOR ####

# bc

1+2+3

7

Type „q‟ to come out

#### TO GET THE HELP RELATED TO ANY COMMAND ####

# man <command name>

# man cat (for example)

Type „q‟ to come out

#### TO SHUTDOWN THE SYSTEM ####

# init 0

#### TO RESTART THE SYSTEM ####

# init 6

#### TO SEARCH FILES OR DIRECTORIES ####

# find / -iname <filename or dirname>

#### TO ACCESS ANY LOCATION IN GUI ####

# nautilus <Path>

# nautilus /etc (for example)

#### TO COPY A EXISTING FILE WITH NEW NAME ####

# cp <source_file> <new_name>

# cp linux unix

# ls (to check)

# cat unix (to read)

#### TO COPY FILE INTO DIFFERENT LOCATION ####

# cp (filename) (destination)

# cp linux /opt

# ls /opt (to check)

#### TO COPY MULTIPLE FILES ####

# cp unix redhat solaris /opt

# ls /opt (to check)

#### TO COPY DATA FROM SOURCE FILE TO DESTINATION WITHOUT

OVERWRITING ####

# cat (source_file) >> (destination_file)

# cat linux >> redhat

# cat redhat (to check)

#### TO COPY A DIRECTORY ####

# cp –rv (source_dir) (destination)

# cp –rv zoom /opt

# ls /opt (to check)

#### TO COPY MULTIPLE DIRECTORIES ####

# cp –rv zoom1 zoom2 zoom3 /opt

# ls /opt (to check)

#### TO COPY COMPLETE DATA FROM PRESENT WORKING LOCATION ####

# cp –rv * /media

# ls /media (to check)

#### TO CUT & PASTE FILE OR DIRECTORIES ####

# mv (source_dir or file) (destination)

# mv zoom /mnt

# ls (to check)

# ls /mnt (to check)

#### TO RENAME A FILE OR DIRECTORY ####

# mv (existing_name) (new_name)

# mv zoom1 zoomgroup

# ls (to check)

#### TO REMOVE A FILE OR DIRECTORY ####

# rm (filename)

# rm –rf (directory_name)

### TO OPEN THE TASK MANAGER ####

# ps –aux

#### TO KILL THE PROCESS OF RUNNING APPLICATION ####

# kill -9 (process_id)

# kill -9 2354 (for example)

#### TO CHECK THE CONFIGURATION OF CPU ####

# cat /proc/cpuinfo

#### TO CHECK THE RUNNING PROCESS OF CPU ####

# top

#### TO CHECK THE OS VERSION ####

# cat /etc/redhat-release

#### TO CHECK THE LAST LOGIN TIME ####

# last

(1)USER ADMINISTRATION PRACTICAL STEPS

'#### TO CREATE A USER ####'

# useradd <username>

# useradd tom

'#### TO CHECK THE USER DETAILS ####'

# cat /etc/passwd (for complete details)

# tail /etc/passwd (for last 10 users details)

# tail -3 /etc/passwd (for last 3 users details)

# head /etc/passwd (for top 10 users details)

# head -3 /etc/passwd (for top 3 users details)

# grep tom /etc/passwd (for particular user details)

'#### ASSIGNING A PASSWORD TO USER ####'

# passwd <username>

# passwd tom

Password: 1

Re-Password: 1

'#### TO CHECK THE USER PASSWORD DETAILS ####'

# cat /etc/shadow

# tail /etc/shadow

'#### TO CHECK THE PASSWORD ENCRYPTION TOOL ####'

# passwd -S <username>

# passwd -S tom

'#### TO LOGIN WITH A USER ####'

# su - tom (In root Console)

# exit (to logout)

# gdmflexiserver (to open extra graphical console)

Select the user and enter the password

Create Some Data

Go to root console by pressing ctrl+alt+F1

And check the user data

# ls /home/tom/Desktop

# who (to get the details of active users)

'#### TO LOCK A USER ####'

# usermod -L <username>

# usermod -L tom

# grep tom /etc/shadow (to check)

'!' sign indicates that a user is lock

# gdmflexiserver

Try to login with user tom

'#### TO UNLOCK A USER ####'

# usermod -U <username>

# usermod -U tom

# grep tom /etc/shadow (to check)

# gdmflexiserver

Try to login with user tom

'#### TO CHECK THE MAIL ACCOUNT OF USERS ####'

# cd /var/spool/mail

# ls (to check)

'#### TO CHECK THE GROUP OF THE USER ####'

# tail /etc/group

GROUP ADMINISTRATION

Content of /etc/group:

The information of each group created is stored in a separate line in the file /etc/group

Each record has 4 fields separated by:

As given:

Linux :                 x:                1000:                   ccna,ccnp

  

Group name:                LINUX

Mask password: X

GIP:                               1000

Secondary mask pwd:ccnp

Content of/etc/gshadow:

This fie content the encrypted group pwd

Passwords are encrypted using MD5(message digest version5)

Linux1:abcd8:adminname:ccna,ccnp

Group name:                                             linux

Encrypted pwd:                                        abcd8

List of administrative members:            adminname

List of members:                                      ccnp

'#### TO CREATE A GROUP ####'

# groupadd <group_name>

# groupadd zoom

# tail /etc/group (to check)

'### TO ADD A SINGLE USER INTO GROUP ###'

# gpasswd -a <username> <groupname>

# gpasswd -a a1 zoom

# grep zoom /etc/group (to check)

'### TO ADD MULTIPLE USERS INTO GROUP ###'

# gpasswd -M a2,a3,a4 zoom

# grep zoom /etc/group (to check)

### TO REMOVE A USER FROM GROUP ###'

# gpasswd -d <username> <groupame>

# gpasswd -d a4 zoom

# grep zoom /etc/group (to check)

'### TO MAKE A USER AS GROUP ADMIN ###'

# gpasswd -A <username> <groupname>

# gpasswd -A a2 zoom

# grep zoom /etc/gshadow (to check)

# su - a2 (to check,login as a user)

# gpasswd -d a3 zoom (try to remove)

# gpasswd -a a5 zoom (try to add)

# grep zoom /etc/group (to check)

# exit (logout)

'### TO RENAME A GROUP ###'

# groupmod -n <newname> <oldname>

# groupmod -n zoomgroup zoom

# tail /etc/group (to check)

'## TO REMOVE A GROUP ###'

# groupdel zoomgroup

# tail /etc/group (to check)

PERMISSIONS

Basic file pemissions:

Files and directory attributes:

Unix/linux files have 8 attributes that can be seen with ls –ld

 commands

Ex: [root@comp1~]#ls  -ld mcse

Note: Only the owner or the root can change the permissions

#### TO CREATE A FILE ####

# cat>mcse

This is a root file

#### TO CHECK THE PROPERTIES OF FILE####

# ls    -ld mcse

                                                                                  

#### TO CHANGE THE PERMISSIONS OF FILES FOR OTHERS####

# chmod 455 mcse

#### TO CHECK  ####

# ls     -ld mcse

#### TO CHANGE THE PERMISSIONS FOR GROUP####

# chmod 45 mcse

#### TO CHECK  ####

# ls     -ld mcse

#### TO CHANGE THE  GROUP OWNER####

#groupadd mcse

#chgrp mcse

#### TO CHECK  ####

# ls     -ld mcse

#### TO CHANGE THE  OWNER####

#chown ccna mcse

#### TO CHECK  ####

# ls     -ld mcse

ACL

Access control list:

Ø Access control is used to apply different permissions for different users& different groups

Ø ACL is imolemented with the help of “setfacl”.

Ø To check the ACL we can use the command”getfacl”

          To apply different permissions for different users

#### TO CREATE A FILE ####

# cat>mcse

This is a root file

#### TO CREATE A USER ####

# useradd u1

# useradd u2

#### TO APPLY ACL ####

#setfacl   _m  u:U1:r,u:U2:w,u:U3:rw  ccnp

#### TO CHECK  ####

#getfacl ccnp

#### TO ALLOW USER  TO ENTER INTO ROOT####

#chmod 666/root

#### TO VERIFY THE RESULT  LOGIN&USER####

#su_u1/ su u1

#### TO APPLY ACL FOR GROUPS####

#groupadd mcse

#groupadd ccna

#groupadd ccnp

Create users to add in  group:

# useradd m1

# useradd m2

# useradd c1

# useradd c2

# useradd n1

# useradd n2

To add all users into group:

#gpasswd  -M m1,m2      mcse

#gpasswd  -M c1,c2         ccna

#gpasswd  -M n1,n2        ccnp

#### TO APPLY DIFFERENT PERMISSIONS FOR DIFFERENT  FOR GROUPS####

#setfacl   _m  g:mcse:4;g:ccna:2;g:linux:6  ccnp

#### TO CHECK  ####

#getfacl ccnp

#### TO VERIFY THE RESULT  LOGIN&USER####

#su m1

#### TO COMEOUT  ####

#exit

PARTITIONS

DIVIDING OF HARDDISK SPACE INTO LOGICAL VALUES:

Advantages:

Ø Installing OS into multiple partitions

Ø To store the data

Ø To check the size of Harddisk

Types of Harddisks and no. of Partitions

#fdisk  -l

#### TO CHECK THE TYPES OF PARTITIONS ####

#parted

There 4 stages of creating Partition:

1^st Stage:

Ø Verify linux partition by assigning sizes

2^nd Stage:

Ø Activating/updating partition KERNEL

3^rd Stage:

Ø Formatting

4^th Stage:

Ø Mounting

Ø Accessing your new partition with the help of directory

'Step 1:-Check the Existing Partitions'

# fdisk -l (to check)

'Step 2:-To create a New Partition'

# fdisk /dev/sda

Press 'm' for help

Press 'p' to check the exisiting partitions

Press 'n' to create a new partition

Enter the Size: +1G (for example)

Press 'p' to check

Press 'w' to save & quit

'Step 3:-Activate the New Changes to Kernel'

# partx -a /dev/sda (run this 2 times)

'Step 4:-Format the Partition'

# mkfs.ext4 <partition_no>

# mkfs.ext4 /dev/sda8 (for example)

'Step 5:-To Use the Partition-Create Mount Point'

# mount <partition_no> <mount_point>

# mount /dev/sda8 /mnt

# mount (to check)

# cd /mnt (to access the partition)

# ls (to check)

'lost+found' dir is the indication of partition

# mkdir zoom{1..100} (create some data)

# ls (to check)

'#### TO CHECK THE FILESYSTEM OF PARTITIONS ####'

# blkid

'#### TO CHECK THE FREE SPACE OF THE PARTITION ###'

# df -h

'#### TO CHECK THE USED SPACE OF THE PARTITION ####'

# du –sh

'#### TO CHECK THE FREE SPACE OF THE HARDISK ####'

# parted

Type: print free

Type: quit (to come out)

'#### TO REMOVE THE MOUNT POINT(LINK) ####'

# umount <partition_no>

# umount /dev/sda8 (for example)

# mount (to check)

'#### TO DO THE PERMANENT MOUNTING ####'

# vim /etc/fstab (open this file)

Come at last & do the changes as given below

/dev/sda11 /mnt ext4 defaults 0 0

'partition_no' 'mount_pt' 'filesystem'

:wq(save & quit the file)

# init 6 (reboot the pc)

# mount (to check the permanent mount point)

LVM(LOGICAL VOLUME MANAGER)

Ø Creating a new partition

Ø Updating the partition

Ø LVM

Ø Formatting

Ø Mounting

è      LVM is a method of Hard disk space into logical  

         Volumes that can be easily resized.

è      With LVM the hard drive or set of hard drives is

          Allocated to one or more physical volumes.

è      The physical volumes are then combined into

 Volume groups.

è      Fetch volume group is divided into logical volumes,  

Which are formatted with a file system like ent3 and are then mounted

##### TO IMPLEMMENT LVM ON PARTITIONS #####

'Step 1:-Create 3 Raw Partitions'

# fdisk -l (to check)

# fdisk /dev/sda (to create-see partition notes)

# partx -a /dev/sda (to update kernel)

'Step 2:-Create Physcial Volume'

# pvcreate <partition_no's>

# pvcreate /dev/sda{12..14} (for example)

# pvdisplay (to check)

'Step 3:-Create Volume Group'

# vgcreate <vg_name> <partition_no's>

# vgcreate zoom /dev/sda{12..14}

# vgdisplay (to check)

'Step 4:-Create Logical Volume'

# lvcreate -L <size> <vg_name> -n <lv_name>

# lvcreate -L +500M zoom -n linux

# lvdisplay (to check)

'Step 5:-Format LV & Mount to Use'

# mkfs.ext4 /dev/zoom/linux

# mkdir /lvm (create new dir for mount point)

# mount /dev/zoom/linux /lvm (to mount)

# mount (to check)

# cd /lvm (access mount point to use LV)

# mkdir zoom{1..100} (create some data)

# ls (to check)

# df -h (to check the free space of partition)

'Step 6:-To Resize the Partition'

# cp -rv /usr/* /lvm (to make partition size full)

# df -h (check the size)

# lvresize -L +500M /dev/zoom/linux (to resize)

# resize2fs /dev/zoom/linux (to resize filesystem)

# df -h (check the extended size)

'Step 7:-To Remove LVM Concept from Partition'

# umount /lvm (un mount the lv)

# lvremove /dev/zoom/linux (1st remove lv)

# lvdisplay (to check)

# vgremove /dev/zoom (2nd remove vg)

# vgdisplay (to check)

# pvremove /dev/sda{12..15} (3rd remove pv's)

# pvdisplay (to check)

SWAP: Swap is called as Logical RAM. It is used to create

      Free space for the physical RAM.

By making(accessing and sleeping memory into SWAP)

There by a SWAP increases system performances

##### TO CREATE A SWAP PARTITION #####

'Step 1:-Check the RAM size'

# free -m (to check the RAM size in MB)

'Step 2:-Create One Partition'

# fdisk /dev/sda (to create)

Press 'n' to create new partition

Enter the size: +4G (for example 4GB)

Press 't' to change the ID of Partition

Enter Partition No:16 (for example)

Press 'L' to get the list of availabel ID's

Enter 82 for swap

Press 'p' to check

Press 'w' to save & quit

'Step 3:-Update & Format the Partition'

# partx -a /dev/sda (to update)

# mkswap /dev/sda16 (to create swap filesystem)

# blkid /dev/sda16 (to check)

'Step 4:-Enable the Swap Service'

# swapon /dev/sda16 (to enable)

# free -m (to check RAM size)

# swapon -s (to check the status of swap partition)

'Step 5:-To Disable the Swap Service'

# swapoff /dev/sda16 (to disable)

# free -m (to check the RAM size)

# swapon -s (to check the status)        

FTP SERVER

FTP SERVERS ARE TWO TYPES:

Ø DOWNLOADING

Ø UPLOADING

FTP(File Transfer Protocol):

Ø FTP is one of the oldest member of tcp/ip protocol stack and still in common use

Ø As the name suggests, it is optimized for transferring files

NOTE: This was introduced by USRVM

FTP SERVER FOR LINUX/UNIX:

VSFTPD: Very Secure FTP Document

Ø It is inbuilt application.

Ø It is securable

WUFTP: Washington Universities(St.LOUIS) FTP

PROFTPD: Professional FTP document.

Aim:  FTP server is used to transfer the file in the form of

          Uploading/Sending and Downloading/Receiving the files

Category: It is a independent service i.e., it can used in any OS.

Package: VSFTP

Configuration file: vi/etc/vsftpd/vsftpd.config

Default path: /var/ftp/pub

Port Numbers: 20-DATA TRANSFER,21-CONTROL CONNECTION   

##### TO CONFIGURE THE FTP SERVER #####

'Step 1:-Check the IP & Assign the Hostname'.

# ifconfig (to check ip)

# hostname ftp.zoom.com

# vi /etc/hosts (provide host entry with ip)

Come at last & provide the ip and hostname as given below:-

192.168.0.100 ftp.zoom.com

:wq(save & quit the file)

# vi /etc/hostname (to make host permanent)

Remove localhost.localdomain and add ftp.zoom.com

:wq(save & quit the file)

'Step 2:-Install the Package'

# yum install vsftpd* -y

'Step 3:-To Provide Downloading'

# cd /var/ftp/pub (for downloading)

# touch linux{1..5}.xls (add files for downloading)

# ls (to check)

'Step 4:-Restart the Service'

# service vsftpd restart

# systemctl enable vsftpd.service (to enable permanently)

# systemctl list-unit-files | grep vsftpd.service (to check)

'Step 5:-Stop the Firewall Service If Enable'

# service firewalld stop (stop firewall service)

# systemctl disable firewalld.service (to disable permanently)

# service iptables stop (stop iptables service)

# systemctl disable iptables.service

DISABLE SELINUX SERVICE PERMANENTLY

# vim /etc/selinux/config (open selinux conf file)

Go to line number 7 & change the Status as given below

SELINUX=disabled

:wq(save & quit the file)

# init 6 (restart is required to update selinux service)

'Step 6:-Check the Result From Client'

IN THE CLIENT PC

# yum install ftp* -y (install this command)

# ftp <server_ip>

# ftp 192.168.0.100 (for example)

Username: ftp (for public user)

Password: enter

ftp> ls

ftp> cd pub

ftp> ls (to check files)

ftp> mget linux* (to download multiple files)

ftp> bye (logout)

# ls (to check the downloaded files)

# firefox ftp://192.168.0.100 (to access in gui)

'Step 7:-To Provide Uploading - Go to FTP SERVER'

# cd /var/ftp (in ftp server pc)

# mkdir upload (create one dir for uploading)

# chmod 777 upload (give full permission)

# vim /etc/vsftpd/vsftpd.conf (open configuration file)

Go to the line no.29 & remove # sign

:wq(save & quit the file)

# service vsftpd restart

'Step 8:-To Upload - Go to Client PC'

# touch unix{1..5}.xls (create some files to upload)

# ftp 192.168.0.100 (access ftp server)

Username:ftp Password:enter

ftp> ls

ftp> cd upload (for uploading)

ftp> prompt (to avoid confirmation)

ftp> mput unix* (to upload multiple files)

ftp> bye (to logout)

TO CHECK THE UPLOADED FILES - GO TO FTP SERVER & CHECK IN THE

LOCATION /var/ftp/upload

# ls /var/ftp/upload (in ftp server pc)

'#### TO BLOCK PUBLIC USER ACCESS ####'

# vim /etc/vsftpd/vsftpd.conf

Go to line no.12 & Replace YES with NO at last

:wq(save & quit the file)

# service vsftpd restart

TO CHECK THE RESULT: GO TO THE CLIENT PC & TRY TO ACCESS FTP

SERVER AS A PUBLIC USER

'#### TO BLOCK A PARTICULAR NORMAL USER ACCESS ####'

# cd /etc/vsftpd

# vi ftpusers (open this file)

At the Normal User Name at last line to block

tom (for example)

:wq(save & quit the file)

# service vsftpd restart

TO CHECK THE RESULT: GO TO THE CLIENT PC & TRY TO ACCESS FTP

SERVER AS A NORMAL USER (tom)

'#### TO BLOCK THE ALL NORMAL USER ACCESS ####'

# vim /etc/vsftpd/vsftpd.conf

Go to line no.16 & Replace YES with NO at last

:wq(save & quit the file)

# service vsftpd restart

TO CHECK THE RESULT: GO TO THE CLIENT PC & TRY TO ACCESS FTP

SERVER AS ANY NORMAL USER

DNS(DOMAIN NAMING SYSTEM)

DOMAIN NAMING SYSYTEM:

Ø The DNS is a hierarchical naming system where each level of name separated by a”. ”

Ø It resolves user friendly domain names into computer friendly IP addresses

Ø It also resolves IP address into domain

Ø It provides a centralized database for resolution

ZONE:

Ø Zone is a storage data base which contains the all records.

There are 2 ZONES:

Ø Forward look up zone

Ø Reverse look up zone

Forward look up zone:

Ø Used for resolving Host name to IP addresses

Ø It maintains Host to IP addresses mapping information

Reverse look up zone:

Ø Used for resolving IP addresses to Host name

Ø It maintains IP addresses to Host mapping information

RECORDS

SOA Record:

Ø Start  of authority

Ø It is the first record in zone file

NS Record:

Ø Name  server

Ø Identifies the DNS for each zone

A Record:

Ø Address

Ø Maps a host name into an IP address

CNAME Record:

Ø Canonical name(Alias)

Ø Maps on alias name to hostname

PTR Record:

Ø Pointer

Ø Maps on IP address to a host name

MX Record:

Ø Mail exchange

Ø Maps on a domain name to host name

Aim:DNS server is used to resolve name into IP address and IP

         address into Host name with help of Forward look up zone 

         and Reverse look up zone

Category: It is a independent service can be us as OS.

Package: BIND

Config files: vi/etc/named.config

Default path: var/named,              Port Number: 53

#### TO CONFIGURE THE DNS SERVER ####

'Step 1:-Check the IP & Assign the Hostname'

# ifconfig (to check)

# hostname dns.zoom.com

# vi /etc/hosts (provide host entry with ip)

# vi /etc/hostname (to make host permanent)

'Step 2:-Install the Package'

# yum install bind* -y

'Step 3:-Edit 1st Main Configuration File'

# vim /etc/named.rfc1912.zones

Set the line no & do the modification

line no 19-23 for FORWARD LOOKUP ZONE (FLZ)

line no 31-35 for REVERSE LOOKUP ZOME (RLZ)

(Line no:19-23)

zone "zoom.com" IN {

type master;

file "forward";

allow-update { none; };

};

(Line no:31-35)

zone "0.168.192.in-addr.arpa" IN {

type master;

file "reverse";

allow-update { none; };

};

:wq(save & quit the file)

'Step 4:-Create Zone Files in DNS Database'

# cd /var/named (to access dns database)

# cp -p named.localhost forward (for FLZ)

# cp -p named.loopback reverse (for RLZ)

# ls (to check)

# vim forward

Do the modification as given below near the objects

SOA dns.zoom.com. rname.invalid. (

NS dns.zoom.com.

dns A 192.168.0.100

:wq(save & quit the file)

# vim reverse

Do the modification as given below near the objects

SOA dns.zoom.com. rname.invalid. (

NS dns.zoom.com.

100 PTR dns.zoom.com.

:wq(save & quit the file)

'Step 5:-Edit 2nd Main Configuration File'

# vim /etc/named.conf

Go to line no.11 & add self system ip,as given below

listen-on port 53 { 127.0.0.1;192.168.0.100; };

Go to line no.17 & allow query to all,as given below

allow-query { localhost;any; };

:wq(save & quit the file)

'Step 6:-Edit 3rd M.C.F'

# vim /etc/resolv.conf

nameserver 192.168.0.100

:wq(save & quit the file)

'Step 7:-Restart the Service'

# service named restart

# systemctl enable named.service

'Step 8:-To Check the DNS Configuration'

# dig dns.zoom.com (to resolve with name)

# dig -x 192.168.0.100 (to resolve with ip)

NOTE:-If you got Answer:1,then configuration is correct

If you got Answer:0,then configuration is incorrect

'Step 9:-To Check the Configuration from Client'

Go to Client PC

# vi /etc/resolv.conf (in client pc)

nameserver 192.168.0.100

:wq(save & quit the file)

# dig dns.zoom.com.

# dig -x 192.168.0.100

# ping dns.zoom.com (to check the ip)

'TO ADD THE SERVERS INTO DNS,BELONGS TO SAME DOMAIN'

(1)Configure One Server in Separate PC (for ex:ftp server) with

the Hostname: ftp.zoom.com IP:192.168.0.99 for example

(2)Add this Server Entry with IP into DNS - FLZ file

# cd /var/named (in dns server)

# vim forward (open flz)

add the entry as given below

NS dns.zoom.com.

NS ftp.zoom.com.

dns A 192.168.0.100

ftp A 192.168.0.99 (for ex:ftp server ip)

:wq(save & quit the file)

# service named restart

(3)To check the Result-Go to Client PC & Add the DNS

Ip into resolv.conf file & try to access FTP Server with

name (ftp://ftp.zoom.com)

APACHE

WEB SERVER

WEB SERVER: To host web pages which contains information

Web server in Unix/Linux:

Ø Tux –in-Kernel web server that supports only text

Ø Apache- The most popular web server

Ø AOL- American Online Free web server

Ø Sun one- web server frm sun previously called as iplanet

Apache:

Ø Apache is a free and open source software

Ø The application is available for a wide variety of OS

Including linux,unix& windows

Ø The majority of all web servers using apache server are Linux web server

Ø It supports virtual hosting

Virtual Hosting:

Ø Hosting more than one web site on a single server is called as Virtual Hosting

Ø Types of Virtual Hosting:

§  Name based virtual hosting

§  Ip based virtual hosting

§  Port based virtual hosting

AIM:  Web server is used to host the web pages ,to publish the

           information to the publisher

Category:  It is independent service

Package: httpd.rpm

Configuration: vi/etc/httpd/conf

Default path: /var/www/html

Port number: 60

Service: httpd

###TO CHECK THE IP ADDRESS###

#ping 192.168.0.250

###TO ASSIGN HOST NAME###

#hostname www.zoom.com

#vi/etc/hostname

###TO INSTALL THE PACKAGE###

#yum install http –y

###GO TO CONFIGURATION FILE###

<virtualHost                                                  *:80>

Server Name                                                 www.zoom.com

Server Admin                                                root@www.zoom.com

Document Root                                            /var/www/html

Directory Index                                             zoom.html

</virtualHost>

###GO TO DEFAULT PATH###

#cd /var/www/html

###CREATE WEB PAGE USING HTML###

#vi    zoom.html

<html>

<body bgcolor=blue>

<marquee><h1>welcome</h1>

</marquee>

</html>

###RESTART THE SERVICE###

#systemCH            restart                             httpd.service

#iptube      -F

#setenforce 0

###TO CHECK WEB PAGE###

#vu/etc/hosts

###TO ACCESS FROM IP ADDRESS###

#vi/etc/httpd/conf/httpd.com

:s nu

G  i

<virtual host 192.168.0.18:80>

Esc

:nq

#systemCH restart httpd.service

###TO HOST WEB PAGE ON DIFFERENT PORT NUMBERS###

<isten2007

192.168.0.18:2007>

DHCP(DYNAMIC HOST CONFIGURATION PROTOCOL)

Aim: DHCP server is used to assign the ip address automatically

Category:  It is independent service

Package: dhcp

Configuration: vi  etc/dhcp/dhcp.conf

Working: It works on  “DORA” process

                    D=Discovery

                    O=Offer

                    R=Request

                    A=Acknowledge                             

Port number: 61(DHCP Server),             68(DHCP CLIENT)

Service: dhcpd

#### TO CONFIGURE THE DHCP SERVER ####

'Step 1:-Install the package'

# yum install dhcp* -y

'Step 2:-Copy Sample Files Data into Main File'

# cd /usr/share/doc/dhcp*

# ls (to check)

# cp dhcpd.conf.example /etc/dhcp/dhcpd.conf

'Step 3:-Edit the M.C.F'

# vim /etc/dhcp/dhcpd.conf

Set the line no's & Do the changes from line no.47-53

(line no:47-networkaddress,48-ip range,49-dns ip,50-domain name,51-

gateway,52-broadcast ip,53-time)

subnet 192.168.0.0 netmask 255.255.255.0 {

range 192.168.0.160 192.168.0.190;

option domain-name-servers 192.168.0.250;

option domain-name "ldap.zoom.com";

option routers 192.168.0.254;

option broadcast-address 192.168.0.255;

default-lease-time 700;

:wq(save & quit the file)

'Step 4:-Restart the Service & Check Result'

# service dhcpd restart

# systemctl enable dhcpd.service

GO TO LINUX CLIENT:-

# dhclient -v (to get dynamic ip)

# ifconfig (to check dynamic ip)

IN THE CLIENT PC - DYNAMIC IP YOU WILL BE GETTING FROM REVERSE ORDER

FROM DHCP SERVER

'Step 5:-For the Dhcp Reservation'

# arp (client_pc_ip) to get the mac address

# arp 192.168.0.190 (for example)

Copy the MAC Address & Paste in M.C.F

# vim /etc/dhcp/dhcpd.conf

Go to line no.76 & paste mac address as given below

hardware ethernet 00:07:e9:00:02:69;

Go to line no.77 & Reserve the Ip as given below

fixed-address 192.168.0.160;

:wq(save & quit the file)

# service dhcpd restart

TO CHECK THE RESULT - GO TO THE PARTICULAR MAC ADDRESS CLIENT:-

# dhclient -v (run this command)

# ifconfig (to check reserved ip)

MAIL SERVER

To exchange the mail communication

Unix/Linux based mail server

Ø Send mail

Ø Post fix

Ø Qmail

Ø Gmail

Ø Exim

Aim:   Mail server is used to exchange mails for the

            Communication purpose

Category:  It is independent service

Package: postfix

Configuration: vi  /etc/postfix/mail.conf

Working: It works on  “DORA” process

                    D=Discovery

                    O=Offer

                    R=Request

                    A=Acknowledge                             

Port number: INCOMING SERVICES       POP3-110,       imap-143

                             OUTGOING SERVICES     SMTP-25

Service: POSTFIX

###TO CHECK THE IP ADDRESS###

#ifconfig

#ping 192.168.0.250

###TO ASSIGN HOST NAME###

#hostname mail.zoom.com

I

esc

:wq

###TO INSTALL THE PACKAGE###

#yum install postfix –y

###GO TO CONFIGURATION FILE###

#vi   /etc/postfix/main.cf

:se    nu                                                        

75 --mail.zoom.com

83--www.zoom.com

113—remore

116—adding#

###CREATE USERS###

#useradd  u1

#useradd  u2

###ASSIGN THE PASSWORD TO USER###

#passwd U1

#passwd U2

###RESTART THE SERVICE###

#systemCH            restart                             postfix.service

#iptube      -F

#setenforce 0

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