How to configure ssh server in RHEL,Centos,Fedora ?

How to configure ssh server in RHEL,Centos,Fedora?

Step 1:-  First Install openssh client and server In RHEL,Centos,Fedora via yum .Run below command in terminal .

yum -y install openssh-server openssh-clients

Step 2:-  Now verify openssh rpm installed successfully or not .Run below command in terminal .

rpm -qa openssh*


Step3:-  Now go to /etc/ssh directory and edit sshd_config.

vi /etc/ssh/sshd_config

By Default root login enable in ssh.

PermitRootLogin yes 

Change it like below

PermitRootLogin no


 AllowUsers rahul pooja

Uncommet port 22  like below

 port 22

save and exit Press Esc key and type below command

:wq!

Step4:-  Create two users rahul and pooja.

              useradd rahul
              useradd pooja

              Set password of rahul and pooja.
              Run below command

              passwd rahul

enter password of rahul then Press enter and again type same password and press enter

same as follow for pooja user.
passwd pooja

Step5:- now restart ssh service .Run below command in terminal.

                service sshd restart

configure ssh service to start automatically during the system startup on runlevel 3 and 5 .Run below command in terminal.
 
chkconfig --level 35 sshd on


Step 6:-  Open 22 port for ssh server via iptables.Run below command in terminal.

  /sbin/iptables -A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT

To save rule in iptables permanently.Run below command in terminal.

service iptables save


Step 7:-  Login via users rahul and pooja.Run below command in terminal.

               ssh rahul@ip of your ssh server

               ssh -l pooja ip of your ssh server.