In the present days’ business environment, it is difficult for an organization to conduct business without using computers and networks.
Network provides online working environment but networks are also vulnerable to various threats and problems, therefore organization should ensure network security, in order to:
§ Safeguards their assets
§ Ensure and maintain the data integrity
Network Security is broadly classified as:
§ Physical Security: To protect physical assets like CD, hard disk, etc.
§ Logical Security: To protect logical assets like data, programs, etc.
Level of Security:
And for a burst security of networks, organization normally employs a Security Administrator (SA) who implements the different levels of security for different assets using following steps:
§ Prepare a plan for enforcing security.
§ Identify the assets which require security.
§ Value the assets and accordingly analyze for level of security; more valuable asset require higher level of security
§ Identify various threats to individual assets.
§ Identify the probability of threat occurrence.
§ Identify the amount of losses or exposure in case of security breach.
§ Plan for appropriate controls to avoid threats or security breach.
§ Outline or generate reports on level of security provided to individual assets and network systems, etc.
Techniques of Network Security:
§ Firewall is one of the most popular techniques of network security.
§ Firewall provides logical security to organization data and network.
§ Firewall is a computerized electronic system, installed between organization private network and public network from unauthorized access.
§ Firewall is a control for invasive type of subversive threats.
§ Firewall is like an insulator which insulate organization private network from invaders coming through public network.
Types of Firewall:
To understand the types of firewall. First of all understand this example:
§ Have you ever gone to a seminar or program of Minister? You must have noticed that before entering into venue you are first checked for invitation card whether you are authorized to attend program or not.
§ Then again you are checked by security guard for any other (malicious) item which is not allowed.
§ Similar to these, these are two types of firewalls; first firewall just check the data packets coming into private network for authorization, and second firewall check the content of data packets to find out any malicious data in the data packets, which may create the problems for data in the private network.
Network Level Firewalls:
§ This firewall check the source address of incoming data packets to find out whether the data packets are authorized to enter in the private network, or not.
§ To do this checking, network firewall maintains the address list of authorized sources from which the data packets are allowed in the private network.
§ Network firewall rejects the data packets from unauthorized sources.
Application Level Firewalls:
§ This Firewall provides higher level of network security.
§ As mentioned earlier, this firewall checks the data contents of incoming data packets to find out any unauthorized activities in data packets.
§ This Firewall is very complex and expensive to setup.