Telnet

Telnet service is use for remote logging from one host to another host.

Data always transfer into plain format.

    Port number            = 23

    Package                  = telnet-server, telnet

    Configuration File    = /etc/xinetd.d/telnet

    Log file                    = /var/log/secure 

Installation  and configuration 

               #yum install telnet* -y

               # vim /etc/xinetd.d/telnet

In this file edit this-

               Disable = no

after that save the file and restart the service 

              # service xinetd restart

Note:- Telnet service is not enable for root user by defaults.

Telnet User Monitoring tool

                      # who

                #w

                #pinky

                #tail –f /var/log/secure 

On client Side  :-

              # telnet ip of telnet server (Ex. telnet 172.17.1.1)

To allow root user for telnet

              # vim /etc/pam.d/remote

Comment here this line

              # Auth    required  pam_securitty.so

after that save this file.

Check the session process of Telnet user

                    # who –u 

Rules allow/deny for  telnet user

              # vim /etc/xinetd.d/telnet

Insert here rules 

            No_access = IP Address

            Example= 172.17. {5,6,7,8} .example.com 172.17.1.1/16

            Only_from = IP address

            Access_time =give here time (Example10:00-12:00 18:00-20:00)

            Log_type = FILE give here location (example /var/log/kaushal)

            Log_on_sucess +=USERID PID DURATION HOST

            Per_source  = give here host value 

For more option:-

              #man xinetd.conf