Summary


In this chapter, you learned some simple yet fundamental techniques to help protect your Linux computer system against network attacks, break-ins, and inadvertent security lapses.

First, you learned to use the Security Level Configuration tool to choose a basic level of software firewalling (also known as packet filtering) for your Linux system. You then learned to create exceptions to the firewalling rules to allow the types of network traffic you need to allow so that you can provide the services you want to provide. You also learned how to enable and disable SELinux, should you feel that your computer is in a vulnerable enough position to require the extra level of assurance that SELinux offers.

Next, you learned about advanced use of file permissionsincluding some potentially dangerous types of permissionsand how to locate files that have been assigned them.

Then, you learned to restrict use of the su command, perhaps the most powerful and dangerous command in Linux security, to a special group of users who belong to the privileged wheel account.

Finally, you learned to limit the amount of time a remote login session can remain inactive before the system decides that it's a risky session and terminates it.

Although these security measures are only a beginningimportant servers should be fully secured according to a Linux security guide or book and further protected with SELinuxthey do represent enough basic security to get you up and running without obvious risks.



    SAMS Teach Yourself Red Hat(r) Fedora(tm) 4 Linux(r) All in One
    Cisco ASA and PIX Firewall Handbook
    ISBN: N/A
    EAN: 2147483647
    Year: 2006
    Pages: 311
    Authors: David Hucaby

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