Redhat Linux Network Security

Discussion in 'VHDL' started by, Dec 4, 2007.

  1. Guest

    Redhat Linux Network Security

    Covering everything about security would take several volumes of
    books, so we can only look at the basics. We can take a quick look at
    the primary defenses you need in order to protect yourself from
    unauthorized access through telephone lines (modems), as well as some
    aspects of network connections. We won't bother with complex solutions
    that are difficult to implement because they can require a
    considerable amount of knowledge and they apply only to specific

    Instead, we can look at the basic methods of buttoning up your Linux
    system, most of which are downright simple and effective. Many system
    administrators either don't know what is necessary to protect a system
    from unauthorized access, or they have discounted the chances of a
    break-in happening to them. It happens with alarming frequency, so
    take the industry's advice: Don't take chances. Protect your system.

    Weak Passwords

    Believe it or not, the most common access method of breaking into a
    system through a network, over a modem connection, or sitting in front
    of a terminal is through weak passwords. Weak (which means easily
    guessable) passwords are very common. When these are used by system
    users, even the best security systems can't protect against intrusion.

    If you're managing a system that has several users, you should
    implement a policy requiring users to set their passwords at regular
    intervals (usually six to eight weeks is a good idea), and to use non-
    English words. The best passwords are combinations of letters and
    numbers that are not in the dictionary.

    Sometimes, though, having a policy against weak passwords isn't
    enough. You might want to consider forcing stronger password usage by
    using public domain or commercial software that checks potential
    passwords for susceptibility. These packages are often available in
    source code, so they can be compiled for Linux without a problem.

    File Security

    Security begins at the file permission level and should be carried out
    carefully. Whether you want to protect a file from snooping by an
    unauthorized invader or another user, you should carefully set your
    umask (file creation mask) to set your files for maximum security.

    Of course, this is really only important if you have more than one
    user on the system or have to consider hiding information from certain
    users. However, if you are on a system with several users, consider
    forcing umask settings for everyone and set read-and-write permissions
    only for the user, and no permissions for everyone else. This is as
    good as you can get with file security.

    For very sensitive files (such as accounting or employee information),
    consider encrypting them with a simple utility. There are many such
    programs available. Most require only a password to trigger the
    encryption or decryption.

    More information visit
    , Dec 4, 2007
    1. Advertisements

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. Hiranya Samarasekera

    running tomcat as a service in redhat linux

    Hiranya Samarasekera, Aug 20, 2003, in forum: Java
    Hiranya Samarasekera
    Aug 20, 2003
  2. yongsing
    Knute Johnson
    Feb 14, 2004
  3. Private
    Michael Borgwardt
    Dec 11, 2004
  4. Daniel
    Apr 12, 2005
  5. U. George
    U. George
    Aug 11, 2005

Share This Page