Linux Dedicated Server Administration
Linux Dedicated Server Administration basics:
UNIX-Like operating systems
Set up authentication & account management before connecting to the network
• All accounts should have strong passwords.
• Administrative or root accounts should have even stronger passwords or passphrases.
• Only use the administrator or root account when absolutely necessary.
• Assign a unique administrative account and password to each individual to better distinguish activities between multiple administrators.
• Use different passwords for administrator or root and general user accounts.
• Force new users to change their passwords when they first login.
• Regularly review the access list or log for users, especially of root and groups. Look for unexpected rights or changes.
• Limit the use of the same password across dissimilar systems (use of the same password on a less secure system may endanger a more secure system).
• Disable or delete old or unused accounts that belong to people who no longer need access.
• Be sure to have a plan and process for securing administrator and root passwords that allows appropriate access to the server in case of illness, turnover, or unforeseen circumstances.
Install and patch the operating system before connecting to the network
• When installing third party software on the dedicated server, consider using the ports or package trees available with each operating system. This ensures that the software is compiled with all available patches on the computer that it will be installed upon.
• See the list below this section for more information on location of patches for various Unix-Like operating systems.
Run minimum number of services
• Turn off unnecessary services.
• Turn off linuxconf and IRC.
• Disable telentd service, if SSH is installed. Otherwise restrict access to telnetd service.
• For all computers except for email hubs, make sure that the sendmail daemons are not running in daemon mode.
Install filters or firewall
• Install and configure a packet filtering utility such as TCP wrappers, Ipchains, Iptables or a software or hardware firewall to limit access to the computer. The rules should reflect the acceptable use and security policies that have been defined for the computer.
• Set up and review logs
• Install security related software
• Maintain backups and operational continuity
