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Research Note Topic:
Research Note Description:
is the combination of the two words
, as it is a wall that generates heat or fire to protect the system from the outside world.
Need of Firewalls:-
is safe and secure (No other can access your data). The moment your
the data could be accessed by external users (
) who can steal your data, passwords and credit card number .
What are Firewalls ?
are effective means of protecting a local system or network of systems from network-based security threats while at the same time affording access to the outside world via wide area networks and the Internet.
FIREWALLS DESIGN PRINCIPLES :
Information systems in corporations ,government agencies, and other organizations have undergone a steady evolution:
Centralized data processing system, with a central mainframe supporting a number of directly connected terminals.
Local Area Networks (LANs) interconnecting PCs and terminals to each other and the mainframe.
Premises network, consisting of a number of LANs, interconnecting PCs, Servers, and perhaps a mainframe or two.
Enterprise-wide network, consisting of multiple, geographically disturbed premises networks interconnected by a private Wide Area Network (WAN).
Internet connectivity, in which the various premises networks all hook into the Internet and may or may not also be connected by a private WAN.
What are the Characteristics of a Firewall ?
The following lists are the design goals for a Firewall :
All traffic from inside to outside, vice versa, must pass through the firewall.
Only authorized traffic, as defined by local security policy, will be allowed to pass .
The firewall itself is immune to penetration. This implies the use of a trusted system with a secure operating system.
FOUR GENERAL TECHNIQUES USED TO CONTROL ACCESS :
Determines the types of Internet services that can be accessed, inbound or outbound. The firewall may filter traffic on the basis of IP (Internet Protocol) address and TCP (Transport Control Protocol) port number; may provide proxy software that receives and interprets each service request before passing it on.
Determines the direction in which particular service requests may be initiated and allowed to flow through the firewall.
Controls access to a service according to which user is attempting to access it. This feature is typically applied to userís inside the firewall perimeter (local users). It may also be applied to incoming traffic from external users.
Controls how particular services are used. For example, the firewall may filter e-mail to eliminate spam, or it may enable external access to only a portion of the information on a local Web server.
CAPABILITIES OF FIREWALL :
It provides protection from various kinds of IP spoofing and routing attacks.
It provides a location for monitoring security-related events.
It is a convenient platform for several Internet functions that are not security related.
It can be used to implement virtual private networks.
FIREWALLS HAVE A NUMBER OF LIMITATIONS:
Firewalls must be updated with a list of inappropriate banned websites, as new sites appear very quickly.
Firewalls are not an effective protection against software viruses. We recommend that all users install anti--virus software.
Often Firewalls are positioned between an Internet router and the internal LAN, this results in a network bottleneck. Careful consideration should be paid to where a firewall is placed. We recommend that the firewall is installed between a switch and an Internet router.
Firewalls cannot protect against 'back doors', where a single network user has installed a separate Internet connection. To prevent this, companies should put an effective Internet access policy in place.
Equipped with the correct password, hackers can gain access to your network in spite of a firewall. To solve this, all passwords should be changed regularly.
The firewall does not protect against internal threats, such as disgruntled employee or an employee who unwittingly cooperates with an external attacker.
TYPES OF FIREWALLS
There are three types of firewalls:
Prof. Ashay Dharwadker