Prof. Michael P. Harris, CCNA, CCAI
Director, Cisco Networking Academy
Computer Science Department
ITSY 1300 - Fundamentals of Information Security
(Version 20070911)
Lab #02 - Computer Security Overview
Network Security policies:
An organization's information is one of its most valuable assets. Network security is
becoming increasingly important as networks become larger and more complex.
Today's mobile and telecommuting users require access locally as well as from
outside the network. Threats to an organization's resources can come from internal
as well as external sources. Information theft and destruction as well as resource
access denial are real concerns for users and system administrators. The overall goal
of any information security system is to ensure that information is accurate and
available where and when needed. There are a number of components that must
interact in a comprehensive network security policy.
Physical Access Security - The first line of defense locally to protect network
equipment such as servers, switches, and routers is to keep them in a locked, climate
controlled, and fire protected environment. If equipment is not physically accessible
to unauthorized personnel, there is less chance of accidental or intentional
tampering.
Login / Password Security - Login and password security policy require that any
user accessing a workstation or server have a valid login ID and password. Windows
NT, Windows 2000, Windows XP, Novell Netware, and UNIX all have specific
requirements for creating and changing passwords. The system administrator can
also require that passwords be changed periodically. Setting screen savers that time
out and activate your workstation lock are additional measures that enhance login
security.
File Systems Security - A major component in any comprehensive security policy, file
system security determines who can get to what data and what they can do with it.
System administrators set up file system security based on users, groups, and
permissions.
Virus protection - Viruses can do tremendous damage to individual workstations and
network servers. Many network operating systems and workstations require antivirus software for adequate protection. UNIX is susceptible to virus attacks like other
operating systems, but most viruses are written for Windows based systems because
the viruses can affect more systems faster. In addition, most virus creators are not
familiar with the UNIX environment enough to know how to create a "UNIX" virus.
Remote Access Security - With increases in telecommuting, the network must allow
legitimate users to access resources remotely while protecting them from
unauthorized access. Access servers and software provide this function.
Internet Firewalls - Organizations that maintain Internet web sites need protection
from hackers. Various software and hardware solutions are available to help ensure
that web servers are available to provide services to legitimate users.
Data backups - A comprehensive security policy must include regular backups of
important data to minimize downtime in the event of a security breach or disaster
such as fire or flood. Backup media such as tapes should be kept offsite in a climate
controlled secure environment. Test restores of data should be performed
periodically to ensure that data can be recovered from the backups.
Disaster Recovery Plan - A written plan is needed that identifies critical data and
documents by functional department within an organization. It describes protective
measures and steps necessary to ensure that the organization can continue to
operate and get back to business quickly with minimum impact to customers.
Audits - Security audits should be performed periodically to ensure that the
organization and its users are following the security policy and preparing adequately
for disaster recovery. Security Audit tools are also available for system
administrators to analyze and detect security loopholes such as files with open
permissions.
Summary:
The primary function of system security is to deny access to unauthorized users.
Keeping computer information secure is important to the user and the system
administrator. By protecting their files and accounts from unauthorized use, users
are also protecting their job and reputation. Standard security features include:
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user passwords that restrict access to the system
file and directory protection with permissions
files that control remote logins and commands on individual workstations
other features that enable system administrators to check for security breaches.
On-Line QUIZ:
http://www.delmar.edu/Courses/ITSY1300/Labs/SecurityPolicy.html
(Drag and drop the correct answers beside the matching descriptions.)