Setting up CentOS

Note - Login as root for all the commands below.

To enable telnet

yum install telnet-server

vi /etc/xinetd.d/telnet and change 'disable=no'

chkconfig telnet on

/etc/init.d/xinetd start

To enable FTP

/etc/init.d/vsftpd start
Starting vsftpd for vsftpd:         [ OK ]

If you want the vsftpd service to start and stop when recycling (rebooting) the machine, you can create the following symbolic links:

ln -s /etc/init.d/vsftpd /etc/rc3.d/S56vsftpd
ln -s /etc/init.d/vsftpd /etc/rc4.d/S56vsftpd
ln -s /etc/init.d/vsftpd /etc/rc5.d/S56vsftpd

Now before getting into the details of how to configure Red Hat Linux for root logins, keep in mind that this is VERY BAD security. Make sure that you NEVER configure your production servers for this type of login.

Configure Telnet for root logins

Simply edit the file /etc/securetty and add the following to the end of the file:

pts/0
pts/1
pts/2
pts/3
pts/4
pts/5
pts/6
pts/7
pts/8
pts/9

This will allow up to 10 telnet sessions to the server as root. 

How to add user to sudoers list

1. Open terminal and type visudo
2. Under the line, root ALL=(ALL)   ALL add <user> ALL=(ALL)  ALL
3. Save

How to enable 'switch user' option

http://jorgenmodin.net/index_html/archive/2008/03/12/how-to-enable-switch-user-in-gnome-on-centos-5